UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

(Rule14a-101)

INFORMATION REQUIRED IN PROXY STATEMENT

SCHEDULE 14A INFORMATION

Proxy Statement Pursuant to Section 14(a) of the

Securities Exchange Act of 1934

Check the appropriate box:

ARCA BIOPHARMA, INC.

(Name of Registrant as Specified In Its Charter)

(Name of Person(s) Filing Proxy Statement if Other Than the Registrant)

Payment of Filing Fee (Check the appropriate box)

ARCA BIOPHARMA, INC.

11080 CirclePoint Road, Suite 140

Westminster, Colorado 80020

April 27, 2016, 2018

Dear Stockholders of ARCA biopharma, Inc.:

You are cordially invited to attend the AnnualSpecial Meeting (the “Special Meeting”) of Stockholders (the “Annual Meeting”) of ARCA biopharma, Inc., a Delaware corporation (the “Company” or “ARCA”). The meeting will be held on                 Thursday, June 9, 2016,, 2018 at 9:00 a.m.                  local time at the Boulder Marriott Hotel, 2660 Canyon Boulevard, Boulder, CO 80302.Company’s Headquarters, 11080 CirclePoint Road, Suite 140, Westminster, Colorado 80020.

The matters scheduled to be considered at the meeting are (1) to electapprove amendments to the nomineeCompany’s restated certificate of incorporation, as amended, and authorize the Company’s Board of Directors, (the “Boardif in their judgment it is necessary, to select and file one such amendment to effect a reverse stock split of Directors”), Dr. Linda Grais,the Company’s Common Stock, at a ratio of between1-for-3 and1-for-20, inclusive, such ratio to be determined at the Board of Directors to hold office until the 2019 Annual Meeting of Stockholders, (2) to ratify the selection by the Audit Committeediscretion of the Board of Directors (the “Audit Committee”) of KPMG LLP (“KPMG”) as the independent registered public accounting firm of the Company for its fiscal year ending December 31, 2016, (3) to approve the AmendedDirectors; and Restated ARCA 2013 Equity Incentive Plan, (4) to approve, on an advisory basis, the compensation of the Company’s named executive officers, as disclosed in this proxy statement, and (5)(2) to conduct any other business properly brought before the meeting.Special Meeting. These items of business are more fully described in thisthe enclosed proxy statement, thatwhich you are encouraged to read in its entirety.

In accordance with the Securities and Exchange Commission (“SEC”) rule (“Notice and Access Rule”) that allows companies to furnish their proxy materials (including the form of proxy, this proxy statement and our Annual Report on Form 10-K for the fiscal year ended December 31, 2015, filed with the SEC on March 17, 2016) over the Internet, we intend to send a Notice of Internet Availability of Proxy Materials (“Notice”) on or about April 28, 2016 to ourAll stockholders of record as of April 12, 2016. We will also provide access to our proxy materials over the Internet by April 28, 2016. As a result of the Notice and Access Rule, all stockholders receiving the Notice have the ability to access the proxy materials over the Internet and request to receive a paper copy of the proxy materials by mail. Instructions on how to access the proxy materials over the Internet or to request a paper copy may be found on the Notice. In addition, the Notice contains instructions on how stockholders may request to receive proxy materials electronically by e-mail.

All stockholdersARCA are cordially invited to attend the AnnualSpecial Meeting in person. Whether or not you expect to attend the AnnualSpecial Meeting, please vote your shares as promptly as possible using the enclosed proxy card, or via the Internet or telephone as instructed in the Notice of Internet Availability of Proxy Materials, via the Internet or the telephone, as promptly as possibleenclosed materials, in order to ensure your representation at the AnnualSpecial Meeting. Alternatively, you may follow the procedures outlined in the Notice of Internet Availability of Proxy Materials to request a paper proxy card to submit your vote by mail. Even if you have voted by proxy, you may still vote in person if you attend the Annualmeeting. Please note, however, that if your shares are held of record by a broker, bank or other nominee and you wish to vote at the meeting, you must obtain a proxy issued in your name from that record holder.

Sincerely,

CHRISTOPHER OZEROFF

Secretary, Senior Vice President and General Counsel

ARCA BIOPHARMA, INC.

11080 CirclePoint Road, Suite 140

Westminster, Colorado 80020

NOTICE OF SPECIAL MEETING OF STOCKHOLDERS

TO BE HELD ON                  , 2018

Notice is hereby given that the Special Meeting of Stockholders (the “Special Meeting”) of ARCA biopharma, Inc., a Delaware corporation (the “Company” or “ARCA”) will be held on                 , 2018 at                  local time at the headquarters of the Company, 11080 CirclePoint Road, Suite 140, Westminster, Colorado 80020, for the following purposes:

Please refer to the proxy materials accompanying this Notice for further information about the business to be transacted at the Special Meeting.

The record date for the Special Meeting is                 , 2018. Only stockholders of record at the close of business on that date may vote at the Special Meeting or any adjournment thereof.

By Order of the Board of Directors:

CHRISTOPHER OZEROFF

Secretary, Senior Vice President and General Counsel

WESTMINSTER, CO

                           , 2018

All stockholders are cordially invited to attend the Special Meeting in person. Whether or not you expect to attend the Special Meeting, please vote by proxy, as promptly as possible, to ensure your representation at the Special Meeting.

You may vote by proxy by completing and mailing the enclosed proxy card. If you submit a proxy card, we will vote your shares as you direct. If you submit a proxy card without giving specific voting instructions, those shares will be voted as recommended by our Board of Directors.

You may also vote by proxy via the Internet by going to the websitehttp://www.investorvote.com/ABIO, and following the instructions provided there, or by telephone, by calling the following number:1-800-652-VOTE (8683) using a touch-tone phone and follow the recorded instructions. You will be asked to provide the company number and control number found on the proxy card. Your proxy card, Internet or telephone vote must be received by                  Mountain Time on                 , 2018 to be counted.

We will make all of our proxy materials available on the Internet athttp://www.investorvote.com/ABIO, beginning on or about                 , 2018, and permit voting via the Internet and by telephone as of that date.

If your shares are held by a broker, bank, or other agent, you are considered the beneficial owner of those shares, and your shares are held in “street name.” If you hold your shares in “street name” you will receive instructions from your broker, bank or other agent describing how to vote your shares. If you hold shares in “street name” and do not receive instructions on how to vote your shares, you should contact your broker, bank or other agent promptly and request this information.

Even if you have voted by proxy via one of the procedures listed above, you may still vote in person if you attend the Special Meeting. Please note, however, that if your shares are held of record by a broker, bank or other agent and you wish to vote at the Annual Meeting, you must obtain a proxy issued in your name from that record holder.

ARCA BIOPHARMA, INC.

11080 CirclePoint Road, Suite 140

Westminster, Colorado 80020

NOTICE OF ANNUAL MEETING OF STOCKHOLDERS

TO BE HELD ON JUNE 9, 2016

Notice is hereby given that the Annual Meeting of Stockholders (the “Annual Meeting”) of ARCA biopharma, Inc., a Delaware corporation (the “Company” or “ARCA”) will be held on Thursday, June 9, 2016, at 9:00 a.m. local time at the Boulder Marriott Hotel, 2660 Canyon Boulevard, Boulder, CO 80302, for the following purposes:

1.        To elect the Board of Directors’ nominee, Dr. Linda Grais, to the Board of Directors to hold office until the 2019 Annual Meeting of Stockholders.

2.        To ratify the selection by the Audit Committee of the Board of Directors of KPMG LLP as independent registered public accounting firm of the Company for its fiscal year ending December 31, 2016.

3.        To approve the Amended and Restated ARCA 2013 Equity Incentive Plan.

4.        To approve, on an advisory basis, the compensation of the Company’s named executive officers, as disclosed in this proxy statement.

5.        To conduct any other business properly brought before the meeting.

These items of business are more fully described in the proxy statement accompanying this Notice.

The record date for the Annual Meeting is April 12, 2016. Only stockholders of record at the close of business on that date may vote at the meeting or any adjournment thereof.

WESTMINSTER, CO

APRIL 27, 2016

Pursuant to the Internet proxy rules promulgated by the Securities and Exchange Commission, the Company has elected to provide access to its proxy materials over the Internet. Accordingly, stockholders of record at the close of business on April 12, 2016, will receive a Notice of Internet Availability of Proxy Materials and may vote at the Annual Meeting and any adjournment or postponement thereof. The Company expects to mail the Notice of Internet Availability of Proxy Materials on or about April 28, 2016.

All stockholders are cordially invited to attend the Annual Meeting in person. Whether or not you expect to attend the Annual Meeting, please vote, as instructed in the Notice of Internet Availability of Proxy Materials, via the Internet or the telephone, as promptly as possible in order to ensure your representation at the annual meeting. Alternatively, you may follow the procedures outlined in the Notice of Internet Availability of Proxy Materials to request a paper proxy card to submit your vote by mail. Even if you have voted by proxy, you may still vote in person if you attend the Annual Meeting. Please note, however, that if your shares are held of record by a broker, bank or other agent and you wish to vote at the AnnualSpecial Meeting, you must obtain a proxy issued in your name from that record holder.

ARCA BIOPHARMA, INC.

11080 CirclePoint Road, Suite 140

Westminster, Colorado 80020

PROXY STATEMENT

FOR THE 2016 ANNUALSPECIAL MEETING OF STOCKHOLDERS TO BE HELD ON

JUNE 9, 2016            , 2018

This proxy statement (this “Proxy Statement”) is being furnished to holders of ARCA biopharma, Inc. (sometimes referred to as the “Company,” “ARCA,” “we,” “us,” and “our”) common stock, par value $0.001 per share (the “Common Stock”). Proxies are being solicited on behalf of the Board of Directors of ARCA (the “Board of Directors” or the “Board”) to be used at the AnnualSpecial Meeting of Stockholders (the “Annual“Special Meeting”) to be held on                 Thursday, June 9, 2016,, 2018 at 9:00 a.m.                  local time at the Boulder Marriott Hotel, 2660 Canyon Boulevard, Boulder, CO 80302,headquarters of the Company, 11080 CirclePoint Road, Suite 140, Westminster, Colorado 80020 and at any postponement or adjournment thereof, for the purposes set forth in the Notice of AnnualSpecial Meeting of Stockholders.

ARCA is using the Securities and Exchange Commission (the “SEC”) rule that allows companiesus to furnish theirdeliver a “full set” of our proxy materials over the Internet. As a result, we intend toby mail to all of our stockholders aof record as of                 , 2018 (the “Record Date”). Our proxy materials include the Notice of Internet Availability of Proxy MaterialsSpecial Meeting (the “Notice”) instead of a paper copy of the proxy materials (including the form of proxy,, this Proxy Statement and our Annual Report on Form 10-K for the fiscal year ended December 31, 2015, filed with the SEC on March 17, 2016 (the “2015 Annual Report”), collectively,a proxy card (collectively, the “Proxy Materials”), and we will mail our Proxy Materials on or about                 April 28, 2016. We, 2018. In addition to mailing our Proxy Materials, we will also provide access to our Proxy Materials over the Internet, by                 April 28, 2016. By furnishing the, 2018. The Notice to our stockholders of record, youwill not receive a printed copy ofand the Proxy Materials in the mail. Instead, the Notice instructsStatement instruct you on how to access and review all of the important information contained in the Proxy Statement and Annual Report electronically or to receive a printed version inMaterials via the mail.Internet. The Notice and the Proxy Statement also instructsinstruct you on how you may submit your proxy overvote by mail, the Internet, by toll-free number, or in person at the AnnualSpecial Meeting. Subsequent to receiving the Notice, all stockholders have the ability to access the Proxy Materials over the Internet and request to receive a paper copy of the Proxy Materials by mail. Instructions on how to access the Proxy Materials over the Internet or to request a paper copy may be found on the Notice. In addition, the Notice contains instructions on how stockholders may request to receive Proxy Materials electronically bye-mail.

All stockholders may view and print ARCA’s proxy statement and the 2015 Annual Report, which are available at www.arcabiopharma.com.www.arcabio.com.

QUESTIONS AND ANSWERS ABOUT THESE PROXY MATERIALS AND VOTING

Why didam I receive a notice regardingreceiving these materials?

We have sent you these proxy materials because the availability of the Proxy Materials on the Internet?

As described above, pursuant to rules adopted by the SEC, we have elected to provide access to the Proxy Materials over the Internet. Accordingly, on or about April 28, 2016, we expect to send the Notice to ARCA’s stockholders of record. The Board of Directors is soliciting your proxy to vote at the Annual Meeting. All stockholders will haveSpecial Meeting, including at any adjournments or postponements of the abilitymeeting. You are invited to accessattend the Proxy Materialsannual meeting to vote on the website referredproposals described in this proxy statement. However, you do not need to inattend the Noticemeeting to vote your shares. Instead, you may simply complete, sign and return the enclosed proxy card, or requestfollow the instructions below to receive a printed or electronic set of the Proxy Materials. Instructions on how to access the Proxy Materialssubmit your proxy over the Internettelephone or through the Internet.

We intend to request a printed copy may be found inmail these proxy materials on or about                  , 2018 to all stockholders of record entitled to vote at the Notice.annual meeting.

How do I attend the AnnualSpecial Meeting?

The meeting will be held on                 Thursday, June 9, 2016,, 2018 at 9:00 a.m.                  local time at the Boulder Marriott Hotel, 2660 Canyon Boulevard, Boulder, CO 80302.Company’s headquarters, 11080 CirclePoint Road, Suite 140, Westminster, Colorado 80020. Directions to the AnnualSpecial Meeting may be found at www.arcabiopharma.com.atwww.arcabio.com. Information on how to vote in person at the AnnualSpecial Meeting is discussed below.

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Who can vote at the AnnualSpecial Meeting?

Only stockholders of record at the close of business on April 12, 2016,the Record Date will be entitled to vote at the AnnualSpecial Meeting. On this record date,the Record Date, there were 9,066,348                  shares of Common Stock outstanding and entitled to vote.

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Stockholder of Record: Shares Registered in Your Name

If on April 12, 2016,the Record Date, your shares of our Common Stock were registered directly in your name with ARCA’s transfer agent, Computershare Trust Company N.A., then you are a stockholder of record. As a stockholder of record, you may vote in person at the meetingSpecial Meeting or vote by proxy. Whether or not you plan to attend the meeting,Special Meeting, we urge you to fill out and return the enclosed proxy card or vote by proxy over the telephone or on the Internet as instructed below or return the proxy card we may mail to you to ensure your vote is counted.

Beneficial Owner: Shares Registered in the Name of a Broker or Bank

If, on April 12, 2016,the Record Date, your shares of our Common Stock were held, not in your name, but rather in an account at a brokerage firm, bank, dealer, or other similar organization, then you are the beneficial owner of shares held in “street name” and the Notice isProxy Materials are being forwarded to you by that organization. The organization holding your account is considered to be the stockholder of record for purposes of voting at the AnnualSpecial Meeting. As a beneficial owner, you have the right to direct your broker or other agent regarding how to vote the shares in your account. You are also invited to attend the AnnualSpecial Meeting. However, since you are not the stockholder of record, you may not vote your shares in person at the meeting unless you request and obtain a valid proxy from your broker or other agent.

What am I voting on?

There are four matters scheduled forApproval of amendments to the Company’s restated certificate of incorporation, as amended, and authorization of the Company’s Board of Directors, if in their judgment it is necessary, to select and file one such amendment to effect a vote:reverse stock split of the Company’s Common Stock, at a ratio of between1-for-3 and1-for-20, inclusive, such ratio to be determined at the discretion of the Board of Directors (such proposal, “Proposal No. 1”).

What if another matter is properly brought before the meeting?

The Board of Directors knows of no other matters that will be presented for consideration at the AnnualSpecial Meeting. If any other matters are properly brought before the meeting, it is the intention of the persons named in the accompanying proxy to vote on those matters in accordance with their best judgment.

How do I vote?

You may either vote “For” the nominee to the Board of Directors or you may “Withhold” your vote for the nominee. For all other matters to be voted on, you may vote “For” or “Against” or abstain from voting. The procedures for voting are fairly simple:

Stockholder of Record: Shares Registered in Your Name

If you are a stockholder of record, you may vote in person at the AnnualSpecial Meeting, vote by proxy over the telephone, vote by proxy through the Internet or vote by proxy using athe enclosed proxy card that you may request or that we may elect to deliver at a later time.card. Whether or not you plan to attend the meeting, we urge you to vote by proxy to

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ensure your vote is counted. You may still attend the meeting and vote in person even if you have already voted by proxy.

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Beneficial Owner: Shares Registered in the Name of Broker or Bank

If you are a beneficial owner of shares registered in the name of your broker, bank, or other agent, you should have received a Notice containing voting instructions frominstruction form with these proxy materialsfrom that organization rather than from ARCA. Simply followcomplete and mail the voting instructions in the Notice toinstruction formto ensure that your vote is counted. Alternatively, you may vote by telephone or over the Internet as instructed by your broker or bank. To vote in person at the AnnualSpecial Meeting, you must obtain a valid proxy from your broker, bank, or other agent. Follow the instructions from your broker or bank included with these proxy materials, or contact your broker or bank to request a proxy form.

We provide Internet proxy voting to allow you to vote your shares online, with procedures designed to ensure the authenticity and correctness of your proxy vote instructions. However, please be aware that you must bear any costs associated with your access to the Internet, such as usage charges from Internet access providers and telephone companies.

How many votes do I have?

On each matter to be voted upon, you have one vote for each share of Company Common Stock you ownedown as of April 12, 2016.the Record Date.

What if I return a proxy card or otherwise vote but do not make specific choices?

If you return a signed and dated proxy card or otherwise vote without marking voting selections, your shares will be voted, as applicable, “For” the election ofapproval to effect the nominee for director and “For” Proposals 2, 3 and 4.reverse stock split. If any other matter is properly presented at the meeting, your proxy holder (one of the individuals named on your proxy card) will vote your shares using his or her best judgment.

Who is paying for this proxy solicitation?

We will pay for the entire cost of soliciting proxies. In addition to these proxy materials, the directors and employees may also solicit proxies in person, by telephone, or by other means of communication. Directors and employees will not be paid any additional compensation for soliciting proxies. We may also reimburse brokerage firms, banks and other agents for the cost of forwarding proxy materials to beneficial owners.

What does it mean if I receive more than one Notice?set of Proxy Materials?

If you receive more than one Notice,set of Proxy Materials, your shares may be registered in more than one name or in different accounts. Please follow the voting instructions on each Noticethe proxy cards in the Proxy Materials to ensure that all of your shares are voted.

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Can I change my vote after submitting my proxy?

Yes. You can revoke your proxy at any time before the final vote at the meeting. If you are the record holder of your shares, you may revoke your proxy in any one of the following ways:

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Your most current proxy card or telephone or the Internet proxy is the one that is counted.

If your shares are held by your broker or bank as a nominee or agent, you should follow the instructions provided by your broker or bank.

When are stockholder proposals due for next year’s annual meeting?

To be considered for inclusion in next year’s proxy materials, your proposal must be submitted in writing by December 29, 2016, to ARCA’s Secretary at 11080 CirclePoint Road, Suite 140, Westminster, Colorado, 80020. If you wish to submit a proposal that is not to be included in next year’s proxy materials or nominate a director, you must do so by no earlier than March 11, 2017, and no later than April 10, 2017. You are also advised to review the Company’s Bylaws, which contain additional requirements about advance notice of stockholder proposals and director nominations.

How are votes counted?

Votes will be counted by the inspector of election appointed for the meeting. For Proposal 1, to elect a new director, votesmeeting, who will separately count “For” and “Withhold” will be counted. For Proposals 2, 3 and 4,“Against” votes, “For” and “Against”, abstentions and broker non-votes will be counted.non-votes. Abstentions will be counted towards the vote total for Proposals 2, 3 and 4,Proposal No. 1, and will have the same effect as “Against” votes. Broker non-votes have no effect and willAs described in more detail below, as a “routine” matter, we do not be counted towards the vote total for any proposal.expect a substantial number of brokernon-votes.

What are “brokernon-votes”?

Brokernon-votes occur when banks, brokers or others who hold shares in “street name” for a beneficial owner of shares held in “street name” does not give instructions to the broker or nominee holding the sharesreturn a proxy but provide no instruction as to how to vote.the sharesshould be voted on a particular matter. Generally, if shares are held in street name, the beneficial owner of the shares is entitled to give voting instructions to the broker or nominee holding the shares. If the beneficial owner does not provide voting instructions, the broker or nominee cannomineecan still vote the shares with respect to matters that are considered to be “routine,” but not with respect to “non-routine”“non-routine” matters. Under the rules and interpretations of the New York Stock Exchange, (“NYSE”), “non-routine”“non-routine” matters are matters that may substantially affect the rights or privileges of shareholders,stockholders, such as mergers, shareholderstockholder proposals and elections of directors, even if not contested. Approval of the stock split contemplated in Proposal No. 1 is considered a “routine” matter upon which a broker or nominee may vote without instruction from the beneficial owner.

How many votes are needed to approve eachthis proposal?

How does the Board of Directors recommend that I vote?

4.The Board of Directors recommends that you voteFOR Proposal No. 1.

What is the quorum requirement?

A quorum of stockholders is necessary to hold a valid meeting. A quorum will be present if stockholders holding a majority of the outstanding shares of Common Stock entitled to vote are present at the meeting in person or represented by proxy. On the record date, April 12, 2016,Record Date, there were                  9,066,348 shares of Common Stock outstanding and entitled to vote. Thus, the holders of                 4,533,174 shares of Common Stock must be present in person or represented by proxy at the meeting to have a quorum.

Your shares will be counted towards the quorum only if you submit a valid proxy (or one is submitted on your behalf by your broker, bank or other nominee) or if you vote in person at the meeting. Abstentions and brokernon-votes, if any, will be counted towards the quorum requirement. If there is no quorum, the holders of a majority of shares present at the meeting in person or represented by proxy may adjourn the meeting to another date.

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How can I find out the results of the voting at the AnnualSpecial Meeting?

Preliminary voting results will be announced at the AnnualSpecial Meeting. In addition, final voting results will be published in a current report onForm 8-K that we expect to file within four business days after the AnnualSpecial Meeting. If final voting results are not available to us in time to file aForm 8-K within four business days after the meeting, we intend to file aForm 8-K to publish preliminary results and, within four business days after the final results are known to us, file an additionalForm 8-K to publish the final results.

NO PERSON IS AUTHORIZED TO GIVE ANY INFORMATION OR TO MAKE ANY REPRESENTATION OTHER THAN THOSE CONTAINED IN THIS PROXY STATEMENT, AND, IF GIVEN OR MADE, SUCH INFORMATION MUST NOT BE RELIED UPON AS HAVING BEEN AUTHORIZED. THE DELIVERY OF THIS PROXY STATEMENT SHALL, UNDER NO CIRCUMSTANCES, CREATE ANY IMPLICATION THAT THERE HAS BEEN NO CHANGE IN THE AFFAIRS OF ARCA SINCE THE DATE OF THIS PROXY STATEMENT.What proxy materials are available on the internet?

We will make all of the Proxy Materials available on the Internet athttp://www.investorvote.com/ABIO, beginning on or about                 , 2018, and permit voting via the Internet and by telephone as of that date.

What are the deadlines for submitting stockholder proposals for the 2019 annual meeting?

To be considered for inclusion in next year’s proxy materials, your proposal must be submitted in writing by December 19, 2018, to ARCA’s Secretary at 11080 CirclePoint Road, Suite 140, Westminster, Colorado, 80020. If you wish to submit a proposal that is not to be included in next year’s proxy materials or nominate a director, you must do so by no earlier than March 2, 2019, and no later than April 1, 2019. You are also advised to review the Company’s Bylaws, which contain additional requirements about advance notice of stockholder proposals and director nominations.

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PROPOSAL NO. 1

ELECTION OF BOARDAPPROVAL OF DIRECTORS CERTIFICATES OF AMENDMENT TO THE COMPANY’S

RESTATED CERTIFICATE OF INCORPORATION TO EFFECT A REVERSE STOCK SPLIT

Introduction

The Board has adopted a resolution approving, and recommending to the Company’s Amended andstockholders for their approval, a series of proposed certificates of amendment to the Company’s Restated Certificate of Incorporation provides that(as amended, the “Restated Certificate of Incorporation”) to effect a reverse split of the shares of the Company’s Common Stock at a ratio of between1-for-3 and1-for-20, inclusive, (the “Reverse Stock Split”). The texts of the forms of the proposed certificates of amendment to the Restated Certificate of Incorporation are annexed to this proxy statement as AnnexesA-1 toA-18. Assuming the stockholders approve the proposal, the Board will have the sole discretion under Section 242(c) of Directorsthe General Corporation Law of the State of Delaware (the “DGCL”), as it determines to be in the best interest of the Company and its stockholders, both to select the specific exchange ratio within the designated range of between1-for-3 and1-for-20, inclusive, and also to decide whether or not to proceed to effect a Reverse Stock Split or instead to abandon the proposed certificates of amendment altogether. If a certificate of amendment is divided into three classesfiled with the Secretary of State of the State of Delaware, the certificate of amendment to provide for staggered terms and that each directorthe Restated Certificate of Incorporation will serve for a termeffect the Reverse Stock Split by reducing the outstanding number of three years or less, depending onshares of the class to which the Board of Directors has assigned a director not previously electedCompany’s Common Stock by the stockholders. There are currently no vacancies on the Board of Directors. Vacancies on the Board of Directors mayratio to be filled only by persons elected by a majority of the remaining directors. A director electeddetermined by the Board, but will not increase the par value of Directorsthe Company’s Common Stock, and will not change the number of authorized shares of the Company’s Common Stock. If the Board does not implement an approved Reverse Stock Split prior to filltheone-year anniversary of this meeting, the Board will seek stockholder approval before implementing any Reverse Stock Split after that time.

By approving Proposal No. 1 and the Reverse Stock Split, stockholders will approve each of a vacancyseries of certificates of amendment to the Restated Certificate of Incorporation pursuant to which any whole number of outstanding shares, between and including three and twenty, would be combined into one share of the Company’s Common Stock, and authorize the Board to file only one such certificate of amendment, as determined by the Board in the manner described herein, and to abandon each certificate of amendment not selected by the Board. If approved, the Board may also elect not to effect any Reverse Stock Split and consequently not to file any certificate of amendment to the Restated Certificate of Incorporation. The Board believes that stockholder approval of the series of certificates of amendment granting the Board this discretion, rather than approval of a specified exchange ratio, provides the Board with maximum flexibility to react to then-current market conditions and, therefore, is in the best interests of the Company and its stockholders.

The Company’s Nasdaq Listing Compliance

The Company’s Common Stock is listed on the Nasdaq Capital Market under the symbol “ABIO.” To maintain a listing on the Nasdaq Capital Market, the Company must satisfy the applicable listing maintenance standards established by Nasdaq Stock Market LLC (“Nasdaq”). Among other things, the Company is required to comply with the continued listing requirements of the Nasdaq Capital Market (the “Nasdaq Capital Requirements”). To comply with the Nasdaq Capital Requirements, the Company must meet each of the following requirements:

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To comply with the Nasdaq Capital Requirements, the Company must also meet at least one of the following requirements:

Currently, the Company meets the Nasdaq Capital Requirements, except the $1.00 minimum bid price. Assuming the stockholders approve Proposal No. 1, the Board will determine whether to effect a Reverse Stock Split in the range of between1-for-3 and1-for-20, inclusive, at the ratio determined by the Board to be most likely sufficient to allow the Company to meet and maintain the $1.00 minimum bid price requirement.

Reasons for the Reverse Stock Split

On April 11, 2018, Nasdaq notified us that the bid price of our Common Stock had closed below the required $1.00 per share for 30 consecutive trading days, and, accordingly, that we did not comply with the applicable Nasdaq minimum bid price requirement. We have been provided 180 calendar days by Nasdaq to regain compliance with this requirement. We may be eligible for an additional 180 day extension from Nasdaq.

The Board has considered the potential harm to us of a delisting of our Common Stock and has determined that, if our Common Stock continues to trade below $1.00 per share, the consummation of the Reverse Stock Split is the best way to maintain liquidity by achieving compliance with the Nasdaq Capital Requirements. Approval of Proposal No. 1 will permit us to file one certificate of amendment to the Restated Certificate of Incorporation and the certificate of amendment filed thereby will contain the number of shares selected by the Board within the limits set forth in Proposal No. 1 to be combined into one share of Common Stock.

The Board also believes that the current low per share market price of our Common Stock has a negative effect on the marketability of our existing shares. The Board believes there are several reasons for this effect. First, certain institutional investors have internal policies preventing the purchase oflow-priced stocks. Second, a variety of policies and practices of broker-dealers discourage individual brokers within those firms from dealing inlow-priced stocks. Third, because the brokers’ commissions onlow-priced stocks generally represent a higher percentage of the stock price than commissions on higher priced stocks, the current share price of our Common Stock can result in individual stockholders paying transaction costs (commissions, markups or markdowns) that are a higher percentage of their total share value than would be the case if the share price of the Common Stock were substantially higher. This factor is also believed to limit the willingness of some institutions to purchase the Common Stock. The Board anticipates that a Reverse Stock Split will result in a class, including vacancies createdhigher bid price for our Common Stock, which may help to alleviate some of these problems.

If Proposal No. 1 is approved by the holders of our Common Stock and the Board decides to implement the Reverse Stock Split, the Board will determine the ratio of the Reverse Stock Split, in the range of between1-for-3 and1-for-20, inclusive, as determined in the judgment of the Board to be most likely sufficient to allow us to achieve and maintain compliance with the minimum $1.00 per share requirement for listing on the Nasdaq Capital Market for the longest period of time while retaining sufficient number of outstanding, tradeable shares to facilitate an adequate market. By way of illustration, assuming a per share price of $                , which represents the closing price of our Common Stock on the Nasdaq Capital Market on the Record Date, immediately prior to the filing of the appropriate certificate of amendment to the Restated Certificate of Incorporation, the Board may determine that we should effect a1-for-3 or1-for-20 reverse stock split, with the goal of achieving a bid price of $                 or $                 per share, respectively. Please refer to the section entitled “Effects of the Reverse Stock Split” below for more

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detailed examples of the effects of the range of ratios.

We believe that maintaining listing on the Nasdaq Capital Market will provide us with a market for the Common Stock that is more accessible than if our Common Stock were traded on the OTC Bulletin Board or in the “pink sheets” maintained by the OTC Markets Group, Inc. Such alternative markets are generally considered to be less efficient than, and not as broad as, the Nasdaq Capital Market. Among other factors, trading on the Nasdaq Capital Market increases liquidity and may potentially minimize the spread between the “bid” and “asked” prices quoted by Market Makers (as defined in Nasdaq Rule 5005). Further, a Nasdaq Capital Market listing may enhance our access to capital, increase our flexibility in responding to anticipated capital requirements and facilitate the use of our Common Stock in any strategic or financing transactions that it may undertake. We believe that prospective investors will view an investment in us more favorably if our shares qualify for listing on the Nasdaq Capital Market as compared with the OTC markets.

We expect that a Reverse Stock Split of our Common Stock will increase the market price of the Common Stock so that we are able to maintain compliance with the Nasdaq minimum bid price listing standard. However, the effect of a Reverse Stock Split on the market price of the Common Stock cannot be predicted with any certainty, and the history of similar stock split combinations for companies in like circumstances is varied. It is possible that the per share price of the Common Stock after the Reverse Stock Split will not rise in proportion to the reduction in the number of directors, shall serve for the remaindershares of the full term ofCommon Stock outstanding resulting from the Reverse Stock Split, effectively reducing our market capitalization, and there can be no assurance that class and until the director’s successor is duly elected and qualified. The Company may reducemarket price per post-reverse split share will either exceed or increase the sizeremain in excess of the $1.00 minimum bid price for a sustained period of time. The market price of our Common Stock may vary based on other factors that are unrelated to the number of shares outstanding, including our future performance.

In order to maintain the listing on the Nasdaq Capital Market, we must maintain compliance with the Nasdaq Capital Requirements. As of June 30, 2018, the Company’s Market Value (as defined in Nasdaq Rule 5005) of Listed Securities (as defined in Nasdaq Rule 5005) was $7,741,647, our market value of Publicly Held Shares (as defined in Nasdaq Rule 5005) was $7,650,869 and our stockholders’ equity was $8,998,000. Even if we meet the bid price requirement, if we are unable to comply with the other Nasdaq Capital Requirements, Nasdaq may determine to delist the Company’s Common Stock from the Nasdaq Capital Market.

The Board does not intend for this transaction to be the first step in a series of Directors by resolution adopted by the affirmative voteplans or proposals of a majority of the directors.

There are currently two Class III directors, whose terms expire at the annual stockholders’ meeting in 2018, two Class II directors whose terms expire at the annual stockholders’ meeting in 2017, and one Class I director, whose term expires at the annual stockholders’ meeting in 2016. The Board of Directors has nominated one Class I director, Dr. Linda Grais, for election to the Board of Directors, for a three-year term ending on the date of the annual meeting in 2019 or until her successor is duly elected and qualified or appointed.

If elected at the Annual Meeting, Dr. Grais would serve until the 2019 annual meeting and until her successor has been duly elected and qualified, or, if sooner, until the director’s death, resignation or removal. It is the Company’s policy to encourage directors and nominees for director to attend the Annual Meeting. Three of the Company’s directors then on the Board of Directors attended the 2015 Annual Meeting of Stockholders in person, and two attended by telephone.

Directors are elected by a plurality of the votes of the holders of shares present in person or represented by proxy and entitled to vote on the election of directors. The nominee receiving the highest number of affirmative votes will be elected. The person nominated for election has agreed to serve if elected. The Company’s management has no reason to believe that the nominee will be unable to serve.

Director Qualifications and Diversity

The below paragraphs provide information, as of the date of this proxy statement, about the nominee and current members of the Board of Directors, including age, all positions currently held, principal occupation and business experience for the past five years. In addition to the information presented regarding each nominee’s specific experience, qualifications, attributes and skills that led the Board of Directors to conclude that such director or nominee should be able to serve as a director, the Board of Directors also believes that all of the directors and nominees have a reputation of integrity, honesty and adherence to high ethical standards. They each have demonstrated business acumen and an ability to exercise sound judgment as well as a commitment to service to ARCA and the Board of Directors.

Our Nominating and Corporate Governance Committee considers diversity in the director identification and nomination process. The Nominating and Corporate Governance Committee seeks nominees with a broad diversity of experience, professions, skills, geographic representation and backgrounds. Such Committee does not assign specific weights to particular criteria and no particular criterion is necessarily applicable to all prospective nominees. ARCA believes that the backgrounds and qualifications of the directors, considered as a group, should provide a significant composite mix of experience, knowledge and abilities that will allow the Board of Directors to fulfill its responsibilities. Nominees are not discriminated against on the basis of race, religion, national origin, sexual orientation, disability or any other basis proscribed by law.

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NOMINEEFOR ELECTIONFORA THREE-YEAR TERM EXPIRINGATTHE 2019 ANNUAL MEETING

THE BOARD OF DIRECTORS RECOMMENDS

A VOTE IN FAVOR OF THE NAMED NOMINEE.

Linda Grais, M.D.

Dr. Grais, age 59, has served as a member of the Board of Directors since May 2007. Dr. Grais has been a director of Ocera Therapeutics, Inc., a public biopharmaceutical company, since January 2008 and became President and Chief Executive Officer of Ocera in June 2012. Dr. Grais served as a Managing Member at InterWest Partners, a venture capital firm from May 2005 until February 2011. From July 1998 to July 2003, Dr. Grais was a founder and executive vice president of SGX Pharmaceuticals Inc., a drug discovery company. Prior to that, she was a corporate attorney at Wilson Sonsini Goodrich & Rosati, where she practiced in such areas as venture financings, public offerings and strategic partnerships. Before practicing law, Dr. Grais worked as an assistant clinical professor of Internal Medicine and Critical Care at the University of California, San Francisco. Dr. Grais received a B.A. from Yale University, magna cum laude, and Phi Beta Kappa, an M.D. from Yale Medical School and a J.D. from Stanford Law School. Since September 2015, Dr. Grais has served on the board of PRA Health Sciences, a public contract research organization. Dr. Grais is an appropriate nominee to the Board of Directors because of her diverse training and experience as both a medical doctor and a lawyer, her experience as a founder and senior executive of a pharmaceutical company, and her experience as an investor in new life sciences companies. She also has extensive experience with and knowledge of the Company’s business from her service on the Board of Directors of the Company since 2007.

DIRECTORS CONTINUINGIN OFFICE UNTILTHE 2017 ANNUAL MEETING

Michael R. Bristow, M.D., Ph.D.

Dr. Bristow, age 71, was one of the founders of ARCA in September 2004, and has served as a Director since that time. Dr. Bristow has also served as the Company’s President and Chief Executive Officer since July 2009. Previously, Dr. Bristow served as the President and Chief Executive Officer of the Company from September 2004 to November 2006, and as the Company’s Chief Science and Medical Officer from November 2006 to July 2009. Dr. Bristow is a Professor of Medicine and the former Head of Cardiology at the University of Colorado Health Sciences Center, where he has been since October 1991. Dr. Bristow was one of the founders of Myogen, Inc. and served as Myogen’s Chief Science and Medical Officer from October 1996 to February 2006 and as a Scientific Advisor to Myogen from February 2006 until the acquisition of Myogen by Gilead Sciences, Inc. in November 2006. Dr. Bristow is an appropriate member of the Company’s Board of Directors given his extensive experience and expertise as a cardiologist, medical researcher and drug developer in the field of cardiovascular medicine, and heart failure specifically, and his experience as a founder and manager of cardiovascular-focused, public pharmaceutical company. Dr. Bristow also has extensive experience with, and knowledge of, ARCA’s business, as the founder and former Chief Science and Medical Officer of the Company, and the current President and Chief Executive Officer of ARCA, and as a member of the Board of Directors of ARCA since the founding of the Company.

Robert E. Conway

Mr. Conway, age 62, was appointed to the Board of Directors in September 2013, and has served as the Chairman of our Board of Directors since 2014. Mr. Conway served as the Chief Executive Officer and member of the board of directors of Array Biopharma, a publicly traded pharmaceutical company, from 1999 to 2012. Prior to joining Array, Mr. Conway was the Chief Operating Officer and Executive Vice President of Hill Top Research, Inc., from 1996 to 1999. From 1979 until 1996, Mr. Conway held various executive positions for Corning Inc. including Corporate Vice President and General Manager of Corning Hazleton, Inc., a contract research organization. From 2004 to 2013, he served on the board of directors of PRA International, Inc., which was a public company for a portion of his tenure there, from 2012 to the present, he has served on the board of directors of

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eResearch Technology, Inc., a“going private company, and from 2015 to the present, he has served on the board of directors of Nivalis Therapeutics, Inc. a public, clinical stage pharmaceutical company. Mr. Conway also serves as the Chairman of Wall Family Enterprise, a leading library and educational supplies company. In addition, Mr. Conway is a member of the Strategic Advisory Committee of Genstar Capital, LLC. Mr. Conway received a B.S. in accounting from Marquette University in 1976. He is an appropriate member of the Board of Directors given his experience and expertise in the pharmaceutical industry, in pharmaceutical development and clinical trials, and in corporate finance, governance, accounting and public company compliance.

DIRECTORS CONTINUINGIN OFFICE UNTILTHE 2018 ANNUAL MEETING

Raymond L. Woosley, M.D., Ph.D.

Dr. Woosley, age 73, was appointed to the Board of Directors in July 2013. Dr. Woosley is currently the President Emeritus of the Critical Path Institute (C-Path), a non-profit, public-private partnership with the Federal Food and Drug Administration, of which he was a founder in November 2004, and where he served as President, Chief Executive Officer and Chairman of the board of directors from 2005 to 2011. Since 2012, Dr. Woosley has also been the Director of CredibleMeds Worldwide, an independent, nonprofit research and education organization. Since 2001, Dr. Woosley has also been a Professor of Medicine and Pharmacology at The University of Arizona Health Sciences Center (UAHSC), and, since 2012, Professor Emeritus, where he was also Vice President for Health Sciences from 2001 to 2005, and Dean of the College of Medicine from 2001 to 2002. From 1988 to 2001, Dr. Woosley was a professor of medicine at the Georgetown University School of Medicine, where he was also Director of the Institute of Cardiovascular Sciences from 1994 to 2000, and Division Chief, Clinical Pharmacology, in the Department of Medicine from 1988 to 1994. Dr. Woosley earned his Ph.D. in Pharmacology from the University of Louisville and his M.D. from the University of Miami. Dr. Woosley’s research has been published in over 265 peer-reviewed publications and 50 book chapters. Dr. Woosley is an appropriate member of the Board of Directors, given his expertise and experience in cardiovascular clinical pharmacology, anti-arrhythmic therapeutics, pharmacogenetic drug development and therapeutic regulatory approval.

Dan J. Mitchell

Mr. Mitchell, age 59, was appointed to the Board of Directors in February 2014. He founded, and is a manager of Sequel Venture Partners, L.L.C., a venture capital firm formed in January 1997. Prior to founding Sequel Venture Partners, Mr. Mitchell was a founder of Capital Health Venture Partners, a health care focused venture capital firm, where he was a General Partner from October 1986 until 2006, and he was in the Venture Capital Division of the Trust Department of the First National Bank of Chicago from 1983 to 1985. He currently serves on the board of directors of GlobeImmune, Inc., a publicly traded biopharmaceutical company, and several private companies. Mr. Mitchell holds a B.S. from the University of Illinois and an M.B.A. from the University of California at Berkeley. Mr. Mitchell is an appropriate member of the Board of Directors given his expertise and experience in the pharmaceutical industry, pharmaceutical development, and in corporate finance and governance.

INFORMATION REGARDINGTHE BOARDOF DIRECTORSAND CORPORATE GOVERNANCE

INDEPENDENCEOF THE BOARDOF DIRECTORS

As required under the Nasdaq Stock Market (“Nasdaq”) listing standards, a majority of the members of a listed company’s board of directors must qualify as “independent,” as affirmatively determined by the board of directors. Our Board of Directors consults with the Company’s counsel to ensure that the Board of Directors’ determinations are consistent with relevant securities and other laws and regulations regarding the definition of “independent,” including those set forth in pertinent listing standards of the Nasdaq, as in effect from time to time.

Consistent with these considerations, after review of all relevant identified transactions or relationships between each director, or any of his or her family members, and the Company, its senior management and its independent registered public accounting firm, the Board of Directors has affirmatively determined that the following four directors are independent directorstransaction” within the meaning of the applicable Nasdaq listing standards:

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Mr. Conway, Dr. Grais, Mr. Mitchell and Dr. Woosley. In making this determination, the Board of Directors found that none of the directors or nominees for director had a material or other disqualifying relationship with the Company. Dr. Bristow, the Company’s President and Chief Executive Officer is not an independent director by virtue of his relationship with the Company.

BOARD LEADERSHIP STRUCTURE

The Company has structured its Board of Directors in a way that the Company believes effectively serves its objectives of corporate governance and management oversight. The Company separates the roles of Chief Executive Officer and Chairman of the Board of Directors in recognition of the differences between the two roles. The Company believes that the Chief Executive Officer should be responsible for the day to day leadership and performance of the Company, while the Chairman of the Board of Directors should work with the Chief Executive Officer and the rest of the Board of Directors to set the strategic direction for the Company and provide guidance to, and oversight of the Chief Executive Officer. The Chairman also sets the agenda for meetings of the Board of Directors and presides over them.

Mr. Conway, who is an independent director, was elected Chairman of the Board of Directors in 2014. In this capacity, Mr. Conway, among other things, calls and presides over Board meetings, including meetings of the independent directors, and sets meeting agendas. In this role, Mr. Conway can effectively coordinate between the Board and management regarding risk management issues and the implementation of appropriate responses, and can help ensure the effective independent functioning of the Board of Directors in its oversight responsibilities. Accordingly, the Chairman has substantial ability to shape the work of the Board of Directors.

ROLEOFTHE BOARDOF DIRECTORSIN RISK OVERSIGHTAND RISK MANAGEMENT

One of the Board of Directors’ key functions is informed oversight of the Company’s risk management process. The Board of Directors does not have a standing risk management committee, but rather administers this oversight function directly through the Board of Directors as a whole, as well as through various standing committees of the Board of Directors that address risks inherent in their respective areas of oversight. In particular, while the Board of Directors is responsible for monitoring and assessing strategic risk exposure, the Audit Committee has the responsibility to consider and discuss the major financial risk exposures and the steps management has taken to monitor and control these exposures, including guidelines and policies to govern the process by which risk assessment and management is undertaken. The Audit Committee also monitors compliance with legal and regulatory requirements, in addition to oversight of the performance of ARCA’s accounting and financial reporting processes. The nominating and corporate governance committee of the Board of Directors (the “Nominating and Corporate Governance Committee”) monitors the effectiveness of the corporate governance guidelines, including whether they are successful in preventing illegal or improper liability-creating conduct. The compensation committee of the Board of Directors (the “Compensation Committee”) assesses and monitors whether any compensation policies and programs have the potential to encourage excessive risk-taking. The entire Board of Directors and its committees address risk management issues from time-to-time and at least annually meet with the employees responsible for risk management in the committees’ respective areas of oversight. Both the Board of Directors as a whole and the various standing committees receive periodic reports from the employees responsible for risk management, as well as incidental reports as matters may arise. It is the responsibility of the committee chairs to report findings regarding material risk exposures to the Board of Directors as quickly as possible.

MEETINGSOF THE BOARDOF DIRECTORS

The Board of Directors met six times during the 2015 fiscal year. The independent members of the Board of Directors met separately as a group in connection with each of the four regularly scheduled board meetings in 2015. All members of the Board of Directors attended at least 75% of the meetings of the Board of Directors and at least 75% the meeting of the committees of the Board of Directors of which each director was a member.

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INFORMATION REGARDING COMMITTEESOFTHE BOARDOF DIRECTORS

The Board of Directors has three standing committees: the Audit Committee, the Compensation Committee, and the Nominating and Corporate Governance Committee. The following table provides membership and meeting information for fiscal year 2015, for each of the committees of the Board of Directors:

Below is a description of each committee of the Board of Directors. Each of the committees has authority to engage legal counsel or other experts or consultants, as it deems appropriate to carry out its responsibilities. The Board of Directors has determined that each member of each committee meets the applicable Nasdaq rules and regulations regarding “independence” and that each member is free of any relationship that would impair his or her individual exercise of independent judgment with regard to the Company.

Audit Committee

The Audit Committee was established by the Board of Directors in accordance with Section 3(a)(58)(A)Rule 13e-3 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”),.

Board Discretion to overseeImplement the Company’s corporate accounting and financial reporting processes and audits of its financial statements. For this purpose,Reverse Stock Split

If the Audit Committee performs several functions. The Audit Committee evaluatesBoard determines to effect the performance of and assessesReverse Stock Split, it will consider certain factors in selecting the qualificationsspecific exchange ratio, including prevailing market conditions, the trading price of the independent registered public accounting firm; determinesCommon Stock and approves the engagementsteps that we will need to take in order to achieve compliance with the bid price requirement and other listing regulations of the independent registered public accounting firm; determines whether to retain or terminateNasdaq Capital Market. Based in part on the existing independent registered public accounting firm or to appoint and engage a new independent registered public accounting firm; reviews and approves the retentionprice of the independent registered public accounting firmCommon Stock on the days leading up to perform any proposed permissible non-audit services; monitors the rotation of partnersfiling of the independent registered public accounting firmcertificate of amendment to the Restated Certificate of Incorporation effecting the Reverse Stock Split, the Board will determine the ratio of the Reverse Stock Split, in the range of1-for-3 to1-for-20, inclusive, that, in the judgment of the Board, is the reverse split ratio most likely to allow us to achieve and maintain compliance with the minimum $1.00 per share requirement for listing on the Company’s audit engagement teamNasdaq Capital Market for the longest period of time, while retaining a sufficient number of outstanding, tradeable shares to facilitate an adequate market.

Notwithstanding approval of the Reverse Stock Split by the stockholders, the Board may, in its sole discretion, abandon all of the proposed certificates of amendment and determine prior to the effectiveness of any filing with the Secretary of State of the State of Delaware not to effect the Reverse Stock Split prior to the one year anniversary of this Special Meeting of stockholders, as permitted under Section 242(c) of the DGCL. If the Board fails to implement any of the certificates of amendment prior to the one year anniversary of this meeting of stockholders, stockholder approval would again be required prior to implementing any Reverse Stock Split.

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Consequences if Stockholder Approval for Proposal Is Not Obtained

If stockholder approval for Proposal No. 1 is not obtained, we will not be able to file a certificate of amendment to the Restated Certificate of Incorporation to effect the Reverse Stock Split. Unless the bid price for the Common Stock increases to greater than $1.00 for ten consecutive business days prior to October 8, 2018, then we will not meet the listing requirements for the Nasdaq Capital Market. If compliance is not achieved by October 8, 2018, and Nasdaq does not grant us an additional 180 day extension, then our stock would be delisted from the Nasdaq Capital Market. If we were unable to qualify for the additional compliance period, or if we were unable to regain compliance during any such period, the Common Stock would likely be transferred to the OTC Bulletin Board or OTC Market.

If we fail to meet all applicable Nasdaq Capital Requirements and Nasdaq determines to delist the Common Stock, the delisting could adversely affect the market liquidity of the Common Stock and the market price of the Common Stock could decrease. Delisting could also adversely affect our ability to obtain financing for the continuation of our operations and/or result in the loss of confidence by investors, suppliers, commercial partners and employees. In addition, the limited number of authorized shares of the Common Stock that are neither outstanding nor reserved for issuance could adversely affect the ability of us to raise capital through equity financings.

Effects of the Reverse Stock Split

The following table sets forth the number of shares of our Common Stock that would be outstanding immediately after the Reverse Stock Split at various exchange ratios, based on the 13,923,825 shares of Common Stock outstanding as of June 30, 2018. The table does not account for fractional shares that will be paid in cash.

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If a stockholder owns 10,000 shares of Common Stock prior to the Reverse Stock Split, after the Reverse Stock Split that same stockholder would own 3,333 shares in the case of a Reverse Stock Split at the ratio of1-for-3, 2,500 shares in the case of a Reverse Stock Split at the ratio of1-for-4, 2,000 shares in the case of a Reverse Stock Split at the ratio of1-for-5, 1,666 shares in the case of a Reverse Stock Split at the ratio of1-for-6, 1,428 shares in the case of a Reverse Stock Split at the ratio of1-for-7, 1,250 shares in the case of a Reverse Stock Split at the ratio of1-for-8, 1,111 shares in the case of a Reverse Stock Split at the ratio of1-for-9, 1,000 shares in the case of a Reverse Stock Split at the ratio of1-for-10, 909 shares in the case of a Reverse Stock Split at the ratio of1-for-11, 833 shares in the case of a Reverse Stock Split at the ratio of1-for-12, 769 shares in the case of a Reverse Stock Split at the ratio of1-for-13, 714 shares in the case of a Reverse Stock Split at the ratio of1-for-14, 666 shares in the case of a Reverse Stock Split at the ratio of1-for-15, 625 shares in the case of a Reverse Stock Split at the ratio of1-for-16, 588 shares in the case of a Reverse Stock Split at the ratio of1-for-17, 555 shares in the case of a Reverse Stock Split at the ratio of1-for-18, 526 shares in the case of a Reverse Stock Split at the ratio of1-for-19, and 500 shares in the case of a Reverse Stock Split at the ratio of1-for-20.

The lasting effect of the proposed Reverse Stock Split upon the market price for our Common Stock cannot be predicted, and the history of similar reverse stock splits for companies in like circumstances is varied. We cannot assure you that the market price per new share of our Common Stock after the Reverse Stock Split (which we refer to as “New Shares”) will rise in proportion to the reduction in the number of old shares of our Common Stock outstanding (which we refer to as “Old Shares”) as a result of the Reverse Stock Split. We also cannot assure you that the market price per New Share will either exceed or remain in excess of the $1.00 minimum bid price as required by law; reviewsthe Nasdaq Capital Requirements, or that we will otherwise continue to meet the Nasdaq Capital Requirement, including, for example, the applicable minimum Market Value (as defined in Nasdaq Rule 5005) of Listed Securities (as defined in Nasdaq Rule 5005) requirements. For instance, in 2015 and approves or rejects transactions between2013 we executed a reverse split of our Common Stock in order to maintain compliance with the companyNasdaq Capital Requirements. We cannot assure you that another reverse split of our Common Stock will not be necessary in the future. The market price of our Common Stock is dependent on our financial condition, performance, prospects and any related persons; confers with managementa number of other factors, many of which are unrelated to the number of shares outstanding. If our efforts to meet the Nasdaq Capital Requirements are unsuccessful, our Common Stock would remain subject to delisting.

The liquidity of our Common Stock could be adversely affected by the reduced number of shares that would be outstanding after the Reverse Stock Split, and the independent registered public accounting firm regardingreduced number of shares may make it more difficult to trade shares of the Common Stock. In addition, the Reverse Stock Split will increase the number of our stockholders who own odd lots (less than 100 shares). Stockholders who hold odd lots typically will experience an increase in the cost of selling their shares, as well as possible greater difficulty in effecting those sales.

The Reverse Stock Split will affect all of our holders of Common Stock uniformly and will not affect any stockholder’s percentage ownership interests in the Company or proportionate voting power, except to the extent that the Reverse Stock Split results in any of our stockholders owning a fractional share, in which case such stockholders will receive a cash payment in lieu of such fractional share. The Company’s issued Common Stock will remain fully paid andnon-assessable.

The Reverse Stock Split will not affect the par value of our Common Stock. As a result, upon the effectiveness of internal controls over financial reporting; establishes procedures, as required under applicable law, for the receipt, retention and treatment of complaints received byReverse Stock Split, the Company regarding accounting, internal accounting controls or auditing matters and the confidential and anonymous submission by employees of concerns regarding questionable accounting or auditing matters; and meetsstated capital on our balance sheet attributable to review the Company’s annual audited financial statements and quarterly financial statements with management and the independent registered public accounting firm, including a review of the Company’s disclosures under “Management’s Discussion and Analysis of Financial Condition and Results of Operations.” The Audit Committee is currently composed of three directors: Mr. Conway (chair), Mr. Mitchell and Dr. Woosley. The Audit Committee met four times during the fiscal year. The Board of Directors has adopted a written charter of the Audit Committee that is available to stockholdersour Common Stock will be reduced proportionately based on the Company’s website at www.arcabiopharma.com.

The Board of Directors reviews the Nasdaq listing standards definition of independence for audit committee members on an annual basis and has determined that all members of the Audit Committee are independent (as independence is currently defined in Rule 5605(c)(2)(A)(i) and (ii) of the Nasdaq listing standards). The Board of Directors has also determined that Mr. Conway qualifies as an “audit committee financial expert,” as defined in applicable SEC rules. The Board of Directors made a qualitative assessment of Mr. Conway’s level of knowledge and experience based on a number of factors, including his prior experience, business acumen and independence.

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Report of the Audit Committee of the Board of Directors¹

The Audit Committee has reviewed and discussed the audited financial statements for the fiscal year ended December 31, 2015, with management of the Company. The Audit Committee has discussed with the independent registered public accounting firm the matters required to be discussed by Statement on Auditing Standards No. 61, as amended (AICPA,Professional Standards, Vol. 1, AU section 380), as adopted by the Public Company Accounting Oversight Board (“PCAOB”) in Rule 3200T. The Audit Committee has also received the written disclosures and the letter from the independent registered public accounting firm required by applicable requirements of the PCAOB regarding the independent registered public accounting firm’s communications with the Audit Committee concerning independence, and has discussed with the independent registered public accounting firm the accounting firm’s independence. Based on the foregoing, the Audit Committee has recommended to the Board of Directors that the audited financial statements be included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2015.

Mr. Robert Conway

Mr. Dan Mitchell    

      Dr. Raymond Woosley

Compensation Committee

The Compensation Committee is currently composed of three directors: Mr. Robert Conway, Dr. Linda Grais (chair) and Dr. Raymond Woosley. All members of the Compensation Committee are independent, as independence is currently defined in Rule 5605(a)(2) of the Nasdaq listing standards. The Compensation Committee met five times during the fiscal year. The Compensation Committee has adopted a written charter that is available to stockholders on the Company’s website at www.arcabiopharma.com.

The Compensation Committee of the Board of Directors acts on behalf of the Board of Directors to review, adopt and oversee the Company’s compensation strategy, policies, plans and programs, including:

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Compensation Committee Processes and Procedures

Typically, the Compensation Committee meets on a regular basis as it deems appropriate. The agenda for each meeting is usually developed by the Chair of the Compensation Committee. The Compensation Committee meets regularly in executive session. However, from time to time, various members of management and other employees as well as outside advisors or consultants may be invited by the Compensation Committee to make presentations, to provide financial or other background information or advice or to otherwise participate in Compensation Committee meetings. The Chief Executive Officer may not participate in, or be present during, any deliberations or determinations of the Compensation Committee regarding his compensation or individual performance objectives. The Compensation Committee has the sole authority to retain compensation consultants to assist in its evaluation of executive and director compensation, including the authority to approve the consultant’s reasonable fees and other retention terms.

In June 2013, the Company’s Compensation Committee reviewed the Company’s executive compensation in light of general market conditions in the life science industry. As part of this review process, the Compensation Committee identified a peer group of biotechnology companies that it viewed as having a similar profile to ARCA at that time.

In setting 2015 base salary and cash bonus award amounts for the ARCA Named Executive Officers, the Compensation Committee took into account peer group data and factors specific to the Company, and targeted cash compensation to be consistent with these metrics. The Compensation Committee recommended, and the Board of Directors approved, a base salary of $286,759 for Dr. Bristow, the Company’s President and Chief Executive Officer, a base salary of $285,600 for Mr. Keuer, the Company’s Chief Operating Officer, and a base salary of $280,273 for Mr. Ozeroff, the Company’s Senior Vice President and General Counsel, for the fiscal year 2015. In early 2016, Compensation Committee recommended and the Board of Directors approved cash bonuses based on previous performance for the Named Executive Officers (as defined below), and also approved increases to Named Executive Officer salaries for the fiscal year 2016 as described in below under “Executive Compensation”.

Historically, the Compensation Committee has made most of the significant adjustments to annual compensation, determined bonus and equity awards and established new performance objectives at one or more meetings held during the first quarter of the year. The Company has deferred equity awards for 2016 and future performance pending final approval of ARCA’s amended and restated 2013 Equity Incentive Plan by the Company’s stockholders, but expects to make such grants later in the year. However, the Compensation Committee also considers matters related to individual compensation, such as compensation for new executive hires, as well as high-level strategic issues, such as the efficacy of the Company’s compensation strategy, potential modifications to that strategy and new trends, plans or approaches to compensation, at various meetings throughout the year. Generally, the Compensation Committee’s process comprises two related elements: the determination of compensation levels and the establishment of performance objectives for the current year.

The Compensation Committee reviews and approves the compensation of the Chief Executive Officer and the other executive officers of the Company, including annual base salaries, annual and long-term incentive or bonus awards, employment agreements, and severance and change in control agreements/provisions, in each case as, when and if appropriate, and any special or supplemental benefits. For executives other than the Chief Executive Officer, the Compensation Committee solicits and considers evaluations and recommendations submitted to the Compensation Committee by the Chief Executive Officer. The Compensation Committee evaluates the performance of the Chief Executive Officer in light of Company and individual goals and objectives, and makes appropriate recommendations for improving performance. In performing the evaluation, the Chair of the Compensation Committee may solicit comments from the other non-employee members of the Board of Directors and lead the Board of Directors in an overall review of the Chief Executive Officer’s performance in an executive session of non-employee members of the Board of Directors. If the compensation for the Chief Executive Officer or any other executive officer is governed by an employment agreement, the Compensation Committee approves such employment agreement and any amendments thereto.

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For all executives as part of its deliberations, the Compensation Committee may review and consider, as appropriate, materials such as financial reports and projections, operational data, tax and accounting information, tally sheets that set forth the total compensation that may become payable to executives in various hypothetical scenarios, executive and director stock ownership information, company stock performance data, analyses of historical executive compensation levels and current Company-wide compensation levels.

Nominating and Corporate Governance Committee

The Nominating and Corporate Governance Committee is responsible for identifying, reviewing and evaluating candidates to serve as directors of the Company (consistent with criteria approvedexchange ratio selected by the Board for the Reverse Stock Split, and the additionalpaid-in capital account will be credited with the amount by which the stated capital is reduced. The per share net income or loss and net book value of Directors), reviewing and evaluating incumbent directors, recommendingour Common Stock will be increased because there will be fewer shares of our Common Stock outstanding. In addition, proportionate adjustments will be made to the Board of Directors candidates for election to the Board of Directors, making recommendations to the Board of Directors regarding compensation for service on the Board of Directorsper share exercise price and the committees thereof, making recommendationsnumber of shares issuable upon the exercise or settlement of all outstanding options, restricted stock units and warrants to the Boardpurchase or acquire, as applicable, shares of Directors regarding the membership of the committees of the Board of Directors, assessing the performance of the Board of Directors and developing a set of corporate governance principles for the Company. The Nominating and Corporate Governance Committee is currently composed of three directors, Dr. Grais, Mr. Mitchell and Dr. Woosley (chair). All members of the Nominating and Corporate Governance Committee in 2015 were independent (as independence is currently defined in Rule 5605(a)(2) of the Nasdaq listing standards). The Nominating and Corporate Governance Committee met four times during the 2015 fiscal year. The Nominating and Corporate Governance Committee has adopted a written charter that is available to stockholders on the Company’s website atwww.arcabiopharma.com.

The Nominating and Corporate Governance Committee periodically reviews the compensation of non-employee Directors for service on the Board of Directors and committees thereof. In 2015, the Nominating and Corporate Governance Committee began a review of its Director compensation levels in light of general market conditions in the life science industry and in comparison to other clinical stage biopharmaceutical companies. In early 2016, the Nominating and Corporate Governance Committee recommended, and the Board of Directors approved, revised compensation for non-employee Directors, discussed in “Director Compensation” below.

The Board of Directors has adopted a process for identifying and evaluating director nominees, including stockholder nominees. Before recommending an individual to the Board of Directors for membership on the Board of Directors, the Nominating and Corporate Governance Committee canvasses its members and the Company’s management team for potential candidates for the Board of Directors. The Nominating and Corporate Governance Committee also uses its network of contacts to identify potential candidates and, if it deems appropriate, may also engage a professional search firm. The Nominating and Corporate Governance Committee will consider stockholders’ recommendations for nominees to serve as director if notice is timely received by the Secretary of the Company. Candidates nominated by stockholders will be evaluated in the same manner as other candidates. The Nominating and Corporate Governance Committee keeps the Board of Directors apprised of its discussions with potential nominees, and the names of potential nominees received from its current directors, management, and stockholders, if the stockholder notice of nomination is timely made.

Although the Board of Directors has not adopted a fixed set of minimum qualifications for candidates for membership on the Board of Directors, the Nominating and Corporate Governance Committee generally considers several factors in its evaluation of a potential member, such as the candidate’s education, professional background and field of expertise including industry or academic experience in the pharmaceutical and biotechnology fields, experience in corporate governance and management, the reasonable availability of the potential member to devote time to the affairs of the Company, as well as any other criteria deemed relevant by the Board of Directors or the Nominating and Corporate Governance Committee. However, the Nominating and Corporate Governance Committee retains the right to modify these qualifications from time to time. Candidates for director nominees are reviewed in the context of the current composition of the Board of Directors, the operating requirementsCommon Stock of the Company, and the long-term interestsnumber of stockholders. In conductingshares reserved for issuance pursuant to our existing equity incentive, stock option and employee stock purchase plans will be reduced proportionately based on the exchange ratio selected by the Board for the Reverse Stock Split.

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The Reverse Stock Split will have no effect on the total number of shares of Common Stock we are authorized to issue under the Restated Certificate of Incorporation. Therefore, upon effectiveness of the Reverse Stock Split, the number of shares of Common Stock that are authorized and unissued will increase relative to the number of issued and outstanding shares. We may use the additional authorized and unissued shares of our Common Stock resulting from the Reverse Stock Split to issue additional shares of our Common Stock from time to time in equity financings, under our equity compensation plans or in connection with other matters. The Board currently has no plans, arrangements or understandings regarding the issuance of such additional authorized and unissued shares of the Company’s Common Stock.

Our Common Stock is currently registered under Section 12(b) of the Exchange Act, and we are subject to the periodic reporting and other requirements of the Exchange Act. The proposed Reverse Stock Split will not affect the registration of the Common Stock under the Exchange Act. If the proposed Reverse Stock Split is implemented, the Common Stock will continue to be reported on the Nasdaq Capital Market under the symbol “ABIO.”

Potential Anti-Takeover Effect of the Reverse Stock Split

Upon effectiveness of the Reverse Stock Split, the number of authorized shares of Common Stock that are not issued or outstanding will increase relative to the number of shares of Common Stock that are issued and outstanding prior to the Reverse Stock Split. Although this assessment,increase could, under certain circumstances, have an anti-takeover effect (for example, by permitting issuances that would dilute the Nominating and Corporate Governance Committee typically considers diversity, age, skills and such other factors as it deems appropriate givenstock ownership of a person seeking to effect a change in the current needscomposition of the Board or contemplating a tender offer or other transaction for the combination of Directorsthe Company with another company), Proposal No. 1 is not being proposed in response to any effort of which we are aware to accumulate shares of our Common Stock or to obtain control of the Company.

Effective Date

The Reverse Stock Split will be effected at 5:01 p.m. Eastern time, on the date that the certificate of amendment to the Restated Certificate of Incorporation is filed with the Secretary of State of the State of Delaware. Beginning at the effective time of the Reverse Stock Split, each certificate representing Old Shares will be deemed for all corporate purposes to represent New Shares. The texts of the proposed certificates of amendment to the Restated Certificate of Incorporation are in the forms annexed to this proxy statement asAnnexes A-1 throughA-18.

Exchange of Stock Certificates

The transfer agent for the Company will act as the “exchange agent” for purposes of implementing the exchange of stock certificates. Holders of Old Shares will be asked to surrender to the exchange agent certificates representing Old Shares in exchange for certificates representing New Shares in accordance with the procedures to be set forth in a letter of transmittal to be sent by the exchange agent. No new certificates will be issued to a stockholder until the stockholder has surrendered the stockholder’s outstanding certificate(s) together with the properly completed and executed letter of transmittal to the exchange agent. Stockholders should not destroy any stock certificates and should not submit any certificates until requested to do so.

Fractional Shares

No fractional shares of Common Stock will be issued as a result of the proposed Reverse Stock Split. Instead, stockholders who otherwise would be entitled to receive fractional shares will, upon surrender to the exchange agent of certificates representing their fractional shares, be entitled to receive cash in an amount equal to the product obtained by multiplying (i) the closing sales price of our Common Stock as reported on the Nasdaq Capital Market on the effective date of the certificate of amendment to the Restated Certificate of Incorporation by (ii) the number of shares of our Common Stock held by such stockholder before the Reverse Stock Split that would otherwise have been exchanged for such fractional share interest. Holders of as many as nineteen shares (if we were to implement a1-for-20 Reverse Stock Split) of our Common Stock would be eliminated as a result of the cash payment in lieu of any issuance of fractional shares or interests in connection with the Reverse Stock Split. The exact number by which the number of

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holders of our Common Stock would be reduced will depend on the Reverse Stock Split ratio adopted and the Company,number of stockholders that hold less than the Reverse Stock Split ratio as of the effective date of the Reverse Stock Split. As of the Record Date, there were approximately         holders of record of our Common Stock, of which                 were holders of less than 20 shares of our Common Stock. As a result of the Reverse Stock Split, assuming the maximum Reverse Stock Split ratio of1-for-20 were selected, we estimate that cashing out fractional stockholders would potentially reduce that number of stockholders of record to         maintain.

Federal Income Tax Consequences of the Reverse Stock Split

The following is a balancesummary of knowledge, experiencecertain material federal income tax consequences of the Reverse Stock Split to certain holders of Old Shares, but does not purport to be a complete discussion of all of the potential tax considerations relating thereto. This summary is based on the provisions of the United States federal income tax law (including the Internal Revenue Code of 1986, as amended (the “Code”), Treasury Regulations promulgated thereunder, and capability.judicial and administrative interpretations thereof) as of the date hereof, all of which are subject to change retroactively as well as prospectively. Our views regarding the tax consequences of the Reverse Stock Split are not binding upon the Internal Revenue Service or the courts, and there can be no assurance that the Internal Revenue Service or the courts will accept the positions expressed below. This summary assumes that the Old Shares were, and the New Shares will be, held as a “capital asset,” as defined in the Code (i.e., generally, property held for investment). Further, it does not discuss any state, local, foreign or other tax consequences. In addition, this summary does not address the tax consequences applicable to a holder’s particular circumstances or to holders that are subject to special tax rules, including without limitation banks, insurance companies, regulated investment companies, personal holding companies, foreign entities, nonresident alien individuals, broker-dealers, traders,tax-exempt entities and persons who hold Old Shares as a position in a hedging transaction, “straddle,” “conversion transaction” or other risk reduction transaction. THIS SUMMARY OF CERTAIN MATERIAL U.S. FEDERAL TAX CONSIDERATIONS IS FOR GENERAL INFORMATION ONLY AND IS NOT TAX ADVICE. EACH STOCKHOLDER IS URGED TO CONSULT WITH SUCH STOCKHOLDER’S OWN TAX ADVISOR WITH RESPECT TO THE TAX CONSEQUENCES OF THE REVERSE STOCK SPLIT.

Other than the cash payments, if any, received by a stockholder in lieu of fractional shares as discussed below, no gain or loss should be recognized by a stockholder upon such stockholder’s exchange of Old Shares for New Shares pursuant to the Reverse Stock Split. The Nominatingaggregate tax basis of the New Shares received pursuant to the Reverse Stock Split will be the same as the stockholder’s aggregate tax basis in the Old Shares exchanged therefor, less any basis attributable to fractional share interests. Stockholders who receive cash in lieu of fractional share interests in the New Shares as a result of the Reverse Stock Split will be treated as having received the fractional shares pursuant to the Reverse Stock Split and Corporate Governance Committee believes it is essential that Board of Directors members come fromthen as having exchanged the fractional shares for cash in a variety of backgrounds and experiences.

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In the case of incumbent directors whose terms of office are set to expire, the Nominating and Corporate Governance Committee reviews these directors’ overall contributions toredemption by the Company, and the Board of Directors during their terms, including level of attendance, level of participation, quality of performance and contributionwill generally recognize gain or loss equal to the Boarddifference between the amount of Directors’ responsibilitiescash received in lieu of a fractional share and actions, and any relationships and transactions that might impairtheir adjusted basis allocable to the directors’ independence. Infractional share interests redeemed. Such gain or loss will be long term capital gain or loss if the case of new director candidates,Old Shares were held for more than one year. The stockholder’s holding period for the Nominating and Corporate Governance Committee also determines whetherNew Shares will include the nominee is independent for Nasdaq and SEC purposes,period during which determination is based upon applicable Nasdaq listing standards, applicable SEC rules and regulations and the advice of counsel, if necessary. The Nominating and Corporate Governance Committee conducts any appropriate and necessary inquiries intostockholder held the backgrounds and qualifications of possible candidates after consideringOld Shares surrendered in the function and needsReverse Stock Split.

No gain or loss will be recognized by us as a result of the Board of Directors. The Nominating and Corporate Governance Committee meetsReverse Stock Split.

No Dissenters’ Rights

Under applicable Delaware law, the Company’s stockholders are not entitled to discuss and consider the candidates’ qualifications and then determines whether to recommend a nomineedissenters’ or appraisal rights with respect to the Board of Directors by majority vote.

Stockholders who wish to recommend individuals for consideration by the Nominating and Corporate Governance Committee to become nominees for electionproposed amendment to the BoardRestated Certificate of Directors may do so by delivering a written recommendationIncorporation to effect the Nominating and Corporate Governance Committee addressed to the Corporate Secretary, between 60 and 90 days before the one year anniversary date of ARCA’s last annual meeting of stockholders. Recommendations must include the full name of the proposed nominee, a description of the proposed nominee’s business experience for at least the previous five years, complete biographical information, a description of the proposed nominee’s qualifications as a director, and a representation that the recommending stockholder is a beneficial or record owner of ARCA’s stock. AnyReverse Stock Split. We will not independently provide our stockholders with any such submission must be accompanied by the written consent of the proposed nominee to be named as a nominee and to serve as a director if elected. To date, the Nominating and Corporate Governance Committee has not rejected a timely director nominee from a stockholder.

In 2015, the Nominating and Corporate Governance Committee did not pay any fees to assist in the process of identifying or evaluating director candidates.

STOCKHOLDER COMMUNICATIONS WITH THE BOARD OF DIRECTORS

Stockholders who wish to communicate with the Board of Directors may do so by e-mail by using the following email address:directors@arcabiopharma.com; or by mail by following the directions as set forth on ARCA’s website at www.arcabiopharma.com, under the section titled “Corporate Governance” and the subsection titled “Governance Documents”.

CODEOF BUSINESS CONDUCTAND ETHICS

The Company has adopted the ARCA biopharma, Inc. Code of Business Conduct and Ethics that applies to all officers, directors and employees. The Code of Business Conduct and Ethics is available on the Company’s website at www.arcabiopharma.com. If the Company makes any substantive amendments to the Code of Business Conduct and Ethics or grants any waiver from a provision of the Code of Business Conduct and Ethics to any executive officer or director, the Company will promptly disclose the nature of the amendment or waiver on its website and file any current report on Form 8-K required by applicable law or Nasdaq listing standards.

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PROPOSAL 2

RATIFICATIONOF SELECTIONOFTHE INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

The Audit Committee has selected KPMG LLP (“KPMG”) as the Company’s independent registered public accounting firm for the fiscal year ending December 31, 2016, and has further directed that management submit the selection of the independent registered public accounting firm for ratification by the stockholders at the Annual Meeting. KPMG has audited the Company’s fiscal year financial statements since 2009. Representatives of KPMG are expected to be present at the Annual Meeting. They will have an opportunity to make a statement if they so desire and will be available to respond to appropriate questions.

Neither the Company’s Bylaws nor other governing documents or law require stockholder ratification of the selection of KPMG as the Company’s independent registered public accounting firm. However, the Board of Directors is submitting the selection of KPMG to the stockholders for ratification as a matter of good corporate practice. If the stockholders fail to ratify the selection, the Audit Committee will reconsider whether or not to retain that firm. Even if the selection is ratified, the Audit Committee in its discretion may direct the appointment of a different independent registered public accounting firm at any time during the year if they determine that such a change would be in the best interests of the Company and its stockholders.Vote Required

The affirmative vote of the holders of a majority of theall outstanding shares present in person or represented by proxy and entitled to vote at the Annual Meeting will be required to ratify the selection of KPMG. Broker non-votes are counted towards a quorum, but are not counted for any purpose in determining whether this matter has been approved.

PRINCIPAL ACCOUNTANT FEESAND SERVICES

The following table represents aggregate fees billed, or expected to be billed, to the Company for the fiscal year ended December 31, 2015, and December 31, 2014, by KPMG, the Company’s independent registered public accounting firm.

All fees described above were approved by the Audit Committee.

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PRE-APPROVAL POLICIESAND PROCEDURES

The above services performed by the independent registered public accounting firm were pre-approved in accordance with the pre-approval policy and procedures adopted by the Audit Committee. This policy describes the permitted audit, audit-related, tax, and other services that the independent registered public accounting firm may perform. The policy also requires that the independent registered public accounting firm provide in writing:

The services expected to be performed by the independent registered public accounting firm during the subsequent fiscal year are presented to the Audit Committee for pre-approval. Any pre-approval must describe, in writing, the particular service or category of services.

Requests for audit, audit-related, tax, and other services not contemplated by those pre-approved services must be submitted to the Audit Committee for specific pre-approval. Generally, pre-approval is considered at the Audit Committee’s regularly scheduled meetings. However, the authority to grant specific pre-approval between meetings, as necessary, has been delegated to the chairman of the Audit Committee. In the event that the chairman is not available, the other two Audit Committee members together have the authority to grant specific pre-approval between meetings. The chairman or the other members must update the Audit Committee at the next regularly scheduled meeting of any services that were granted specific pre-approval.

The Audit Committee pre-approved all audit related, tax and other services rendered in 2015 and did not rely on the waiver of pre-approval requirement provided by paragraph (c)(7)(i)(C) of Rule 2-01 of Regulation S-X promulgated under the Exchange Act.

THE BOARD OF DIRECTORS RECOMMENDS

A VOTE IN FAVOR OF PROPOSAL 2.

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PROPOSAL 3

APPROVALOFTHE AMENDEDAND RESTATED ARCA 2013 EQUITY INCENTIVE PLAN

The Amended and Restated ARCA biopharma, Inc. 2013 Equity Incentive Plan, or Amended Plan, was adopted by our Board of Directors on April 22, 2016, subject to stockholder approval. We are asking our stockholders to approve the Amended Plan, which amends and restates the 2013 Equity Incentive Plan, to:

Impact of Stockholder Approval

Approval of the Amended Plan will allow us to continue to grant stock awards at levels determined appropriate by our Board of Directors and Compensation Committee. The Amended Plan will allow us to utilize a broad array of equity incentives and performance cash incentives to secure and retain the services of our employees, consultants and directors, and to provide long term incentives that align the interests of our employees, consultants and directors with the interests of our stockholders.

In addition, the Amended Plan retains its provisions that are designed to protect our stockholders’ interests and to reflect corporate governance best practices including:

Stockholder approval of the Amended Plan will not affect any awards that are already outstanding underproposed certificates of amendment to the 2013 Equity Incentive Plan.

We manage our long-term stockholder dilution by limiting the numberRestated Certificate of equity incentive awards granted annually. The Board of Directors monitors our annual stock award Burn Rate, Dilution and Overhang (each as

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defined below), among other factors, in its efforts to maximize stockholders’ value by granting what, in the Board of Directors’ judgment, are the appropriate number of equity incentive awards necessary to attract, reward, and retain employees, consultants and directors. The table below illustrates our Burn Rate, Dilution, and Overhang for the past three fiscal years with details of each calculation noted below the table.

If our request to approve the Amended Plan is approved by our stockholders, we will have a share reserve available for grant as described below under “Description of the Amended Plan – Shares Available for Awards”, which we anticipate being a sufficient share reserve for stock awards to be granted over a period of approximately three years following our 2016 Annual Meeting of Stockholders. We believe that this pool size is necessary to provide sufficient reserved shares for a level of grants that will attract, retain, and motivate employees and other participants over that time period in a competitive hiring environment.

If this Proposal is approved by our stockholders, the Amended Plan will become effective on the date of such approval. In the event that our stockholders do not approve this Proposal, the Amended Plan will not become effective and the 2013 Equity Incentive Plan will continue in its current form. This will create serious constraints on our ability to use equity-based compensation to attract, retain and motivate our employees in what is an extremely competitive hiring environment.

Approval of the Amended Plan by our stockholders will also constitute approval of terms and conditionsIncorporation set forth therein that will permit us to grant awards under the Amended Plan that may qualifyin Proposal No. 1 and included as “performance-based compensation” within the meaning of Section 162(m) of the Internal Revenue Code of 1986, as amended (the “Code”). Code Section 162(m) of the Code denies a deduction to any publicly held corporation and its affiliates for certain compensation paid to “covered employees” in a taxable year to the extent that compensation to a covered employee exceeds $1 million. However, some kinds of compensation, including qualified “performance-based compensation,” are not subject to this deduction limitation and we believe it is in the best interests of the Company and our stockholders to preserve the ability to grant “performance-based compensation” under Section 162(m) of the Code. For the grant of awards under a plan to qualify as “performance-based compensation” under Section 162(m) of the Code, among other things, the plan must (i) describe the employees eligible to receive such awards, (ii) provide a per-person limit on the number of shares subject to various types of awards, and the amount of cash that may be subject to performance cash awards, granted to any employee under the plan in any year, and (iii) include one or more pre-established business criteria upon which the performance goals for performance awards may be granted (or become vested or exercisable). These terms must be approved by the stockholders and, accordingly, our stockholders are requested to approve the Amended Plan, which includes terms regarding eligibility for awards, per-person limits on awards and the business criteria for performance awards granted under the Amended Plan (as described in the summary below).

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Description of the Amended Plan

The material features of the Amended Plan are outlined below. This summary is qualified in its entirety by reference to the complete text of the Amended Plan. Stockholders are urged to read the actual text of the Amended Plan in its entirety, which is appended as Appendix A to the copy of this Proxy Statement filed with the SEC, which may be accessed from the SEC’s website at www.sec.gov.

Types of Awards

The terms of the Amended Plan provide for the grant of incentive stock options, nonstatutory stock options, restricted stock awards, restricted stock unit awards, stock appreciation rights, other stock awards, and performance awards that may be settled in cash, stock, or other property.

Shares Available for Awards

If this Proposal is approved, the aggregate number of shares of our Common Stock that may be issued pursuant to stock-based awards under the Amended Plan from and after its effective date will not exceed 1,259,675 shares, which is equal to the sum of (a) 47,654 shares remaining available for grant under the Plan prior to the Effective Date of its amendment and restatement; (b) an additional 1,000,000 newly reserved shares, and (c) any shares subject to stock-based awards granted under the Amended Plan prior to the Effective Date of its amendment and restatement, which become available for grant under the Amended Plan from time to time due to their reversion to the Amended Plan in accordance with its terms, in an amount not to exceed 212,021 shares (such aggregate number of shares described in (a), (b) and (c) above, the “Share Reserve”).

If a stock-based award granted under the Amended Plan (1) expires or otherwise terminates without all of the shares covered by the award being issued, or (2) is settled in cash (that is, the holder of the stock-based award receives cash rather than stock), the expiration, termination, or settlement of the stock award will not reduce or offset the number of shares of our Common Stock that may be issued under the Plan. If any shares of our Common Stock issued under a stock-based award granted under the Amended Plan are forfeited back to or repurchased by us because of the failure to vest, then the forfeited or repurchased shares will revert to and again become available for issuance under the Amended Plan. Any shares that we reacquire in satisfaction of tax withholding obligations on a stock-based award or as consideration for the exercise price or purchase price of a stock-based award will again become available for issuance under the Amended Plan.

As of April 12, 2016, there were 47,654 shares available for grant under the 2013 Equity Incentive Plan. As of April 12, 2016, stock options to purchase approximately 165,264 shares were outstanding and awards other than stock options covering aggregate of 46,757 shares were outstanding. The weighted-average exercise price of all stock options outstanding as of April 12, 2016 was $8.35, and the weighted-average remaining term of such stock options was 8.15 years. As of April 12, 2016, the closing price of our Common Stock as reported on the NASDAQ Global Market was, rounded to the nearest penny, $3.50 per share, a total of 9,066,348 shares of our Common Stock were outstanding.

Eligibility

All of our employees, non-employee directors and consultants are eligible to participate in the Amended Plan and may receive all types of awards; provided that incentive stock options may be granted under the Amended Plan only to our employees (including officers) and employees of our affiliates. As of April 12, 2016, we have 18 employees (including four officers) and four non-employee directors who are eligible for the Amended Plan.

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Grant Limits

Under the Amended Plan, a maximum of 300,000 shares of our Common Stock may be granted to any one participant during any one calendar year pursuant to stock options, stock appreciation rights and other stock awards whose value is determined by reference to an increase over an exercise price or strike price of at least 100% of the fair market value of our Common Stock on the date of grant. However, the Company may make an additional one-time grant of up to 100,000 shares of our Common Stock to any newly-hired employee pursuant to such awards. An option which is canceled (or a freestanding stock appreciation right that has its exercise price reduced to reflect a reduction in the fair market value of our Common Stock) in the same fiscal year of the Company in which it was granted will continue to be counted against such limit for such fiscal year.

A maximum of 50,000 shares of our Common Stock may be granted to any one participant during any one calendar year as a restricted stock award or restricted unit award, subject to vesting conditions based on the attainment during a performance period of the performance goals described below. However, the Company may make an additional one-time grant of up to 15,000 shares of our Common Stock to any newly-hired employee pursuant to such awards.

The maximum amount covered by performance awards that may be granted to any one participant in any one calendar year (whether the grant, vesting or exercise is contingent upon the attainment during a performance period of the performance goals described below) is 100,000 shares of our Common Stock in the case of performance stock awards and $2,000,000 in the case of performance cash awards. Such limits are designed to allow us to grant awards that are exempt from the $1 million limitation on the income tax deductibility of compensation paid per covered employee imposed by Section 162(m) of the Code.

We have added to the Amended Plan an annual limit on non-employee director compensation. The maximum number of shares of Common Stock subject to stock awards granted under the Amended Plan or otherwise during any one fiscal year to any non-employee director, taken together with any cash fees paid by the Company to such non-employee director during that fiscal year for service on the Board, will not exceed $300,000 in total value. The Board may make exceptions to this limit in extraordinary circumstances (for example, to compensate such individual for interim service in the capacity of an officer of the Company), as the Board may determine in its discretion, provided that the non-employee director receiving the additional compensation may not participate in the decision to award this compensation or in other compensation decisions involving non-employee directors.

Administration

The Amended Plan is administered by our Board of Directors, which may in turn delegate authority to administer the Amended Plan to a committee. Our Board of Directors has delegated concurrent authority to administer the Amended Plan to the Compensation Committee, but may, at any time, revert in itself some or all of the power previously delegated to the Compensation Committee. Each of the Board of Directors and the Compensation Committee are considered to be the “Plan Administrator” for purposes of this Proposal. Subject to the terms of the Amended Plan, the Plan Administrator may determine the recipients, numbers and types of awards to be granted, and terms and conditions of the awards, including the period of their exercisability and vesting. Subject to the limitations set forth below, the Plan Administrator also determines the fair market value applicable to a stock award and the exercise price of stock options and stock appreciation rights granted under the Amended Plan.

The Plan Administrator may also delegate to one or more of our officers the authority to designate employees who are not officers to be recipients of certain stock awards and the number of shares subject to such stock awards, provided that such delegation must specify the total number of shares of our Common Stock that may be subject to the stock awards granted by such officer and such officer may not grant a stock award to himself or herself.

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Under the Amended Plan, the Plan Administrator has the authority to reprice any outstanding stock award by reducing the exercise, purchase or strike price of the stock award or to cancel any outstanding stock award that has an exercise price greater than the current fair market value of our Common Stock in exchange for cash or other stock awards without obtaining the approval of our stockholders prior to the repricing or cancellation and re-grant event.

Stock Options

Stock options may be granted under the Amended Plan pursuant to stock option agreements. The Amended Plan permits the grant of stock options that qualify as incentive stock options, or ISOs, and nonstatutory stock options, or NSOs. Individual stock option agreements may be more restrictive as to any or all of the permissible terms described in this section.

The exercise price of NSOs may not be less than 100% of the fair market value of the Common Stock subject to the stock option on the date of grant. The exercise price of ISOs may not be less than 100% of the fair market value of the Common Stock subject to the stock option on the date of grant and, in some cases (see “Limitations” below), may not be less than 110% of such fair market value.

The term of stock options granted under the Amended Plan may not exceed ten years and, in some cases (see “Limitations” below), may not exceed five years. Except as explicitly provided otherwise in an optionholder’s stock option agreement, stock options granted under the Amended Plan generally terminate three months after termination of the optionholder’s service unless (i) termination is due to the optionholder’s disability, in which case the stock option may be exercised (to the extent the stock option was exercisable at the time of the termination of service) at any time within 12 months following termination; (ii) the optionholder dies before the optionholder’s service has terminated, or within the period (if any) specified in the stock option agreement after termination of service for a reason other than death, in which case the stock option may be exercised (to the extent the stock option was exercisable at the time of the optionholder’s death) within 18 months following the optionholder’s death by the person or persons to whom the rights to such stock option have passed; (iii) the optionholder is terminated for cause in which case the stock option will cease to be exercisable immediately upon the optionholder’s termination; or (iv) the stock option by its terms specifically provides otherwise. A stock option term may be extended in the event that exercise of the stock option following termination of service is prohibited by applicable securities laws or if the sale of stock received upon exercise of a stock option would violate our insider trading policy. In no event may a stock option be exercised after its original expiration date.

Acceptable forms of consideration for the purchase of our Common Stock pursuant to the exercise of a stock option under the Amended Plan will be determined by the Plan Administrator and may include (i) cash, check, bank draft or money order made payable to us, (ii) payment pursuant to a program developed under Regulation T as promulgated by the Federal Reserve Board, (iii) Common Stock previously owned by the optionholder, (iv) a net exercise feature (for NSOs only), or (v) other legal consideration approved by the Plan Administrator.

Stock options granted under the Amended Plan may become exercisable in cumulative increments, or “vest,” as determined by the Plan Administrator at the rate specified in the stock option agreement. Shares covered by different stock options granted under the Amended Plan may be subject to different vesting schedules as the Plan Administrator may determine. The Plan Administrator also has flexibility to provide for accelerated vesting of stock options in certain events.

Generally, an optionholder may not transfer a stock option other than by will or the laws of descent and distribution or a domestic relations order with the approval of the Plan Administrator or a duly authorized officer. Additionally, an optionholder may, with the approval of the Plan Administrator or a duly authorized officer, designate a beneficiary who may exercise the stock option following the optionholder’s death.

Limitations on Incentive Stock Options

The aggregate fair market value, determined at the time of grant, of shares of our Common StockAnnexesA-1 throughA-18. Brokernon-votes with respect to ISOs that are exercisable for the first time by an optionholder during any calendar year under all of our stock plans may not exceed $100,000. The stock options or portions of stock options that exceed this limit are

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Proposal No. 1 will be treated as NSOs. No ISO may be grantedvotes “against” the proposal because they represent shares entitled to any person who, at the time of the grant, owns or is deemed to own stock possessing more than 10% of our total combined voting power or that of any affiliate unless the following conditions are satisfied:

The aggregate maximum number of shares of Common Stock that may be issued pursuant to the exercise of ISOs granted under the Amended Plan is 1,259,675 shares.

Restricted Stock Awards

Restricted stock awards may be granted under the Amended Plan pursuant to restricted stock award agreements. A restricted stock award may be granted in consideration for cash, check, bank draft or money order payable to us, the recipient’s services performed for us or an affiliate of ours, or any other form of legal consideration acceptable to the Plan Administrator. Shares of our Common Stock acquired under a restricted stock award may be subject to forfeiture to us in accordance with a vesting schedule to be determined by the Plan Administrator. Rights to acquire shares of our Common Stock under a restricted stock award may be transferred only upon such terms and conditions as are set forth in the restricted stock award agreement. Except as otherwise provided in the applicable restricted stock award agreement, restricted stock awardsvote that have not vested will be forfeited upon the participant’s termination of continuous service for any reason.

Restricted Stock Unit Awards

Restricted stock unit awards may be granted under the Amended Plan pursuant to restricted stock unit award agreements. Payment of any purchase price may be made in any legal form acceptable to the Plan Administrator. We will settle a payment due to a recipient of a restricted stock unit award by delivery of shares of our Common Stock, by cash, by a combination of cash and stock, or in any other form of consideration determined by the Plan Administrator and set forthbeen voted in the restricted stock unit award agreement. Dividend equivalents may be credited in respect of shares of our Common Stock covered by a restricted stock unit award. Restricted stock unit awards may be subject to vesting in accordance with a vesting schedule to be determined by the Plan Administrator. Except as otherwise provided in the applicable restricted stock unit award agreement, restricted stock units that have not vested will be forfeited upon the participant’s termination of continuous service for any reason.

Stock Appreciation Rights

Stock appreciation rights may be granted under the Amended Plan pursuant to stock appreciation right agreements. Each stock appreciation right is denominated in Common Stock share equivalents. The strike price of each stock appreciation right will be determined by the Plan Administrator but will in no event be less than 100% of the fair market value of the stock subject to the stock appreciation right at the time of grant. The Plan Administrator may also impose restrictions or conditions upon the vesting of stock appreciation rights that it deems appropriate. Stock appreciation rights may be paid in our Common Stock, in cash, in a combination of cash and stock, or in any other form of legal consideration approved by the Plan Administrator and set forth in the stock appreciation right agreement. Stock appreciation rights will be subject to the same conditions upon termination and restrictions on transfer as stock options under the Amended Plan.

22.

Performance Awards

The Amended Plan allows us to grant cash and stock based performance awards that may qualify as performance-based compensation that is not subject to the $1 million limitation on the income tax deductibility of compensation paid per covered employee imposed by Section 162(m) of the Code. Performance awards may be granted, vest or be exercised based upon the attainment during a specified period of time of specified performance goals. The length of any performance period, the performance goals to be achieved during the performance period, and the measure of whether and to what degree such performance goals have been attained will be determined by the Compensation Committee, except that the Board of Directors also may make any such determinations to the extent that the award is not intended to comply with Section 162(m) of the Code.

In granting a performance award intended to qualify as “performance-based compensation” under Section 162(m) of the Code, the Compensation Committee will set a period of time, or a performance period, over which the attainment of one or more goals, or performance goals, will be measured. Within the time period prescribed by Section 162(m) of the Code, at a time when the achievement of the performance goals remains substantially uncertain (typically no later than the earlier of the 90th day of a performance period and the date on which 25% of the performance period has elapsed), the Compensation Committee will establish the performance goals, based upon one or more criteria, or performance criteria, enumerated in the Amended Plan and described below. As soon as administratively practicable following the end of the performance period, the Compensation Committee will certify (in writing) whether the performance goals have been satisfied.

Performance goals under the Amended Plan will be based on any one or more of the following performance criteria: revenue; gross margin; operating margin; operating income; pre-tax profit; earnings before interest, taxes and depreciation; net income; cash flow; expenses; the market price of the stock; earnings per share; return on stockholder equity; return on capital; return on net assets; economic value added; number of customers; market share; return on investment; profit after tax; clinical trial milestones; regulatory product approval milestones; strategic partnership milestones; customer satisfaction; and, to the extent that an Award is not intended to comply with Section 162(m) of the Code, other measures of performance selected by the Board of Directors.

Performance goals may be based on a company-wide basis, with respect to one or more business units, divisions, affiliates, or business segments, and in either absolute terms or relative to the performance of one or more comparable companies or the performance of one or more relevant indices. In establishing a performance goal, the Compensation Committee (or the Board of Directors, to the extent that an award is not intended to comply with Section 162(m) of the Code), unless specified otherwise in the award agreement or other document setting forth the performance goals at the time the performance goals are established, will appropriately make adjustments in the method of calculating the attainment of performance goals for a performance period as follows: (1) to exclude restructuring and/or other nonrecurring charges, (2) to exclude exchange rate effects, (3) to exclude the effects of changes to generally accepted accounting principles, (4) to exclude the effects of any statutory adjustments to corporate tax rates, (5) to exclude the effects of any “unusual or infrequently occurring items” as determined under generally accepted accounting principles, (6) to exclude the dilutive effects of acquisitions or joint ventures, (7) to assume that any business divested by the Company achieved performance objectives at targeted levels during the balance of a Performance Period following such divestiture, (8) to exclude the effect of any change in the outstanding shares of Common Stock of the Company by reason of any stock dividend or split, stock repurchase, reorganization, recapitalization, merger, consolidation, spin-off, combination or exchange of shares or other similar corporate change, or any distributions to common stockholders other than regular cash dividends, (9) to exclude the effects of stock based compensation and the award of bonuses under the Company’s bonus plans, (10) to exclude costs incurred in connection with potential acquisitions or divestitures that are required to be expensed under generally accepted accounting principles, (11) to exclude the goodwill and intangible asset impairment charges that are required to be recorded under generally accepted accounting principles, and (12) to exclude the effect of any other unusual, non-recurring gain or loss or other extraordinary item. In addition, the Board of Directors or Compensation Committee retains the discretion to reduce or eliminate the compensation or economic benefit due upon attainment of performance goals and to define the manner of calculating the performance criteria it selects to use for a performance period. Partial achievement of the specified criteria may result in the payment or vesting corresponding to the degree of achievement as specified in the stock award agreement or the written terms of a performance cash award.

23.

Other Stock Awards

Other forms of stock awards valued in whole or in part with reference to our Common Stock may be granted either alone or in addition to other stock awards under the Amended Plan. The Plan Administrator will have sole and complete authority to determine the persons to whom and the time or times at which such other stock awards will be granted, the number of shares of our Common Stock to be granted and all other conditions of such other stock awards. Other forms of stock awards may be subject to vesting in accordance with a vesting schedule to be determined by the Plan Administrator.

Clawback/Recovery

Stock awards granted under the Amended Plan will be subject to recoupment in accordance with any clawback policy we may be required to adopt pursuant to applicable law and listing requirements. In addition, the Board of Directors may impose such other clawback, recovery or recoupment provisions in any stock award agreement as it determines necessary or appropriate.

Changes to Capital Structure

In the event of certain capitalization adjustments, the Plan Administrator will appropriately adjust: (i) the class(es) and maximum number of securities subject to the Amended Plan, (ii) the class(es) and maximum number of securities that may be issued pursuant to the exercise of ISOs, (iii) the class(es) and maximum number of securities that may be awarded to any person pursuant to Section 162(m) limits, and (iv) the class(es) and number of securities and price per share of stock subject to outstanding stock awards.

Corporate Transactions

In the event of a corporate transaction (as defined in the Amended Plan and described below), the Board of Directors will have the discretion to take one or more of the following actions with respect to outstanding stock awards (contingent upon the closing or completion of such transaction), unless otherwise provided in the stock award agreement or other written agreement with the participant or unless otherwise provided by the Board of Directors at the time of grant:

The Board of Directors is not obligated to treat all stock awards or portions of stock awards in the same manner. The Board of Directors may take different actions with respect to the vested and unvested portions of a stock award.

24.

For purposes of the Amended Plan, a corporate transaction will be deemed to occur in the event of a corporate transaction or a change in control. A corporate transaction generally means the consummation of (i) a sale or other disposition of all or substantially all of our consolidated assets, (ii) a sale or other disposition of at least 90% of our outstanding securities, (iii) a merger, consolidation or similar transaction following which we are not the surviving corporation, or (iv) a merger, consolidation or similar transaction following which we are the surviving corporation but the shares of our Common Stock outstanding immediately prior to such transaction are converted or exchanged into other property by virtue of the transaction.

Change in Control

Under the Amended Plan, a stock award may be subject to additional acceleration of vesting and exercisability upon or after a change in control (as defined in the Amended Plan) as may be provided in the stock award agreement or other written agreement with the participant, but in the absence of such provision, or action by the Board of Directors, no such acceleration will occur.

A change of control generally means (i) the acquisition by a person or entity of more than 50% of our combined voting power other than by merger, consolidation or similar transaction, (ii) a consummated merger, consolidation or similar transaction immediately after which our stockholders cease to own more than 50% of the combined outstanding voting power of the surviving entity, (iii) a consummated sale, lease or exclusive license or other disposition of all or substantially of our consolidated assets, or (iv) when a majority of the Board of Directors becomes comprised of individuals whose nomination, appointment, or election was not approved by a majority of the board members or their approved successors.

Plan Amendments and Termination

Our Board of Directors will have the authority to amend or terminate the Amended Plan at any time. However, except as otherwise provided in the Amended Plan, no amendment or termination of the Amended Plan may materially impair any rights under awards already granted to a participant unless agreed to by the affected participant. We will obtain stockholder approval of any amendment to the Amended Plan as required by applicable law and listing requirements. No ISOs may be granted under the Amended Plan after the tenth anniversary of the earlier of the date the Amended Plan was adopted by the Board of Directors or approved by our stockholders.

U.S. Federal Income Tax Consequences

The information set forth below is a summary only and does not purport to be complete. The information is based upon current federal income tax rules and therefore is subject to change when those rules change. Because the tax consequences to any recipient may depend on his or her particular situation, each recipient should consult the recipient’s tax adviser regarding the federal, state, local, and other tax consequences of the grant or exercise of an award or the disposition of stock acquired as a result of an award. The Amended Plan is not qualified under the provisions of Section 401(a) of the Code and is not subject to any of the provisions of the Employee Retirement Income Security Act of 1974. Our ability to realize the benefit of any tax deductions described below depends on our generation of taxable income as well as the requirement of reasonableness, the provisions of Section 162(m) of the Code and the satisfaction of our tax reporting obligations.

Nonstatutory Stock Options

Generally, there is no taxation upon the grant of an NSO. On exercise, an optionholder will recognize ordinary income equal to the excess, if any, of the fair market value on the date of exercise of the stock over the exercise price. If the optionholder is employed by us or one of our affiliates, that income will be subject to withholding taxes. The optionholder’s tax basis in those shares will be equal to their fair market value on the date of exercise of the stock option, and the optionholder’s capital gain holding period for those shares will begin on that date.

Subject to the requirement of reasonableness, the provisions of Section 162(m) of the Code and the satisfaction of a tax reporting obligation, we will generally be entitled to a tax deduction equal to the taxable ordinary income realized by the optionholder.

25.

Incentive Stock Options

The Amended Plan provides for the grant of stock options that qualify as “incentive stock options,” as defined in Section 422 of the Code. Under the Code, an optionholder generally is not subject to ordinary income tax upon the grant or exercise of an ISO. If the optionholder holds a share received on exercise of an ISO for more than two years from the date the stock option was granted and more than one year from the date the stock option was exercised, which is referred to as the required holding period, the difference, if any, between the amount realized on a sale or other taxable disposition of that share and the holder’s tax basis in that share will be long-term capital gain or loss.

If, however, an optionholder disposes of a share acquired on exercise of an ISO before the end of the required holding period, which is referred to as a disqualifying disposition, the optionholder generally will recognize ordinary income in the year of the disqualifying disposition equal to the excess, if any, of the fair market value of the share on the date the ISO was exercised over the exercise price. However, if the sales proceeds are less than the fair market value of the share on the date of exercise of the stock option, the amount of ordinary income recognized by the optionholder will not exceed the gain, if any, realized on the sale. If the amount realized on a disqualifying disposition exceeds the fair market value of the share on the date of exercise of the stock option, that excess will be short-term or long-term capital gain, depending on whether the holding period for the share exceeds one year.

For purposes of the alternative minimum tax, the amount by which the fair market value of a share of stock acquired on exercise of an ISO exceeds the exercise price of that stock option generally will be an adjustment included in the optionholder’s alternative minimum taxable income for the year in which the stock option is exercised. If, however, there is a disqualifying disposition of the share in the year in which the stock option is exercised, there will be no adjustment for alternative minimum tax purposes with respect to that share. In computing alternative minimum taxable income, the tax basis of a share acquired on exercise of an ISO is increased by the amount of the adjustment taken into account with respect to that share for alternative minimum tax purposes in the year the stock option is exercised.

We are not allowed an income tax deduction with respect to the grant or exercise of an ISO or the disposition of a share acquired on exercise of an ISO after the required holding period. If there is a disqualifying disposition of a share, however, we are allowed a deduction in an amount equal to the ordinary income includible in income by the optionholder, subject to Section 162(m) of the Code and provided that amount constitutes an ordinary and necessary business expense for us and is reasonable in amount, and either the employee includes that amount in income or we timely satisfy our reporting requirements with respect to that amount.

Restricted Stock Awards

Generally, the recipient of a restricted stock award (including a restricted stock award that vests based upon the achievement of performance conditions) will recognize ordinary income at the time the stock is received equal to the excess, if any, of the fair market value of the stock received over any amount paid by the recipient in exchange for the stock. If, however, the stock is not vested when it is received (for example, if the employee is required to work for a period of time in order to have the right to sell the stock), the recipient generally will not recognize income until the stock becomes vested, at which time the recipient will recognize ordinary income equal to the excess, if any, of the fair market value of the stock on the date it becomes vested over any amount paid by the recipient in exchange for the stock. A recipient may, however, file an election with the Internal Revenue Service, within 30 days following his or her receipt of the stock award, to recognize ordinary income, as of the date the recipient receives the award, equal to the excess, if any, of the fair market value of the stock on the date the award is granted over any amount paid by the recipient for the stock.

The recipient’s basis for the determination of gain or loss upon the subsequent disposition of shares acquired from stock awards will be the amount paid for such shares plus any ordinary income recognized either when the stock is received or when the stock becomes vested.

Subject to the requirement of reasonableness, the provisions of Section 162(m) of the Code and the satisfaction of a tax reporting obligation, we will generally be entitled to a tax deduction equal to the taxable ordinary income realized by the recipient of the stock award.

26.

Restricted Stock Unit Awards

Generally, the recipient of a stock unit structured to conform to the requirements of Section 409A of the Code or an exception to Section 409A of the Code (including a restricted stock unit award that vests based upon the achievement of performance conditions) will recognize ordinary income at the time the stock is delivered equal to the excess, if any, of the fair market value of the shares of our Common Stock received over any amount paid by the recipient in exchange for the shares of our Common Stock. To conform to the requirements of Section 409A of the Code, the shares of our Common Stock subject to a stock unit award may generally only be delivered upon one of the following events: a fixed calendar date (or dates), separation from service, death, disability or a change in control. If delivery occurs on another date, unless the stock units otherwise comply with or qualify for an exception to the requirements of Section 409A of the Code, in addition to the tax treatment described above, the recipient will owe an additional 20% federal tax and interest on any taxes owed.

The recipient’s basis for the determination of gain or loss upon the subsequent disposition of shares acquired from stock units will be the amount paid for such shares plus any ordinary income recognized when the stock is delivered.

Subject to the requirement of reasonableness, the provisions of Section 162(m) of the Code and the satisfaction of a tax reporting obligation, we will generally be entitled to a tax deduction equal to the taxable ordinary income realized by the recipient of the stock award.

Stock Appreciation Rights

We may grant under the Amended Plan stock appreciation rights separate from any other award or in tandem with other awards under the Amended Plan.

Where the stock appreciation rights are granted with a strike price equal to the fair market value of the underlying stock on the grant date, the recipient will recognize ordinary income equal to the fair market value of the stock or cash received upon such exercise. Subject to the requirement of reasonableness, the provisions of Section 162(m) of the Code, and the satisfaction of a tax reporting obligation, we will generally be entitled to a tax deduction equal to the taxable ordinary income realized by the recipient of the stock appreciation right.

Cash Awards

The payment of a cash award (including a cash award that vests based upon the achievement of performance conditions) will result in the recipient’s recognition of ordinary income equal to the dollar amount received. Subject to the requirement of reasonableness, the provisions of Section 162(m) of the Code, and the satisfaction of a tax reporting obligation, we will generally be entitled to a tax deduction equal to the taxable ordinary income realized by the recipient of the cash award.

New Plan Benefits

All future grants under the Amended Plan are within the discretion of the plan administrator and are therefore not determinable.

27.

Certain Past Grants

The aggregate number of shares of Common Stock subject to stock options granted to our Chief Executive Officer, the other named executive officers (as identified in the Summary Compensation Table, which appears in the section titled “Executive Compensation” within this proxy statement), and the other individuals and groups indicated, under the Original Plan from September 17, 2013, through December 31, 2015, is reflected in the table below. Since its inception, no other person has been granted 5% or more of the total amount of stock options granted under the Original Plan.

The aggregate intrinsic value in the table above represents the total pretax intrinsic value, based on the closing price of our common stock on the NASDAQ Capital Market on December 31, 2015, which would have been received by the option holders had all the option holders with in-the-money options exercised as of that date. Based on this analysis, the options reflected in the table above had no pretax intrinsic value as of such date.

Required Vote and Board of Directors Recommendation

Approval of Proposal 3 requires the affirmative vote of a majority of the shares present or represented by proxy and entitled to vote at the annual meeting.affirmative. Abstentions will be counted toward the tabulation of votes cast on the proposal and willalso have the same effect as “Against” votes. Broker non-votes are counted towards a quorum, but will have no effect onvotes “against” the outcome of the vote.

Our Board of Directors believes that approval of Proposal 3 is in our best interests and the best interests of our stockholders for the reasons stated above.

THE BOARD OF DIRECTORS RECOMMENDS

A VOTE IN FAVOR OF PROPOSAL 3.

28.

PROPOSAL 4

ADVISORY VOTE ON EXECUTIVE  COMPENSATION

Under the Dodd-Frank Wall Street Reform and Consumer Protection Act (the “Dodd-Frank Act”), and Section 14A of the Exchange Act, the Company’s stockholders areproposal because they represent shares entitled to vote to approve, on an advisory basis, the compensation of the Named Executive Officers as disclosed in this proxy statement in accordance with SEC rules. This vote isthat have not intended to address any specific item of compensation, but rather the overall compensation of the Named Executive Officers and the philosophy, policies and practices described in this proxy statement.

The Company has designed its executive compensation program to attract, motivate, reward and retain the senior management talent required to achieve our corporate objectives and to increase long-term stockholder value.

The compensation of the Named Executive Officers subject to the vote is disclosedbeen voted in the Executive Compensation summary below, the compensation tables, and the related narrative disclosure contained in this proxy statement.affirmative.

Accordingly, the Board of Directors is asking the stockholders to indicate their support for the compensation of the Named Executive Officers as described in this proxy statement by casting a non-binding advisory voteTHE BOARD UNANIMOUSLY RECOMMENDS A VOTE “FOR” the following resolution:

“RESOLVED, that the compensation paid to the Company’s named executive officers, as disclosed pursuant to Item 402 of Regulation S-K, including the Executive Compensation discussion below, compensation tables and narrative discussion, is hereby APPROVED.”

This vote is advisory, it is not binding on the Board of Directors. Nevertheless, the views expressed by the stockholders, whether through this vote or otherwise, are important to management and the Board of Directors and, accordingly, the Board of Directors and the Compensation Committee intend to consider the results of this vote in making determinations in the future regarding executive compensation arrangements.

Advisory approval of this proposal requires the vote of the holders of a majority of the shares present in person or represented by proxy and entitled to vote at the annual meeting.

THE BOARD OF DIRECTORS UNANIMOUSLY  RECOMMENDS

A VOTE IN FAVOR OF PROPOSAL 4

29.13

SECURITY OWNERSHIPOF

CERTAIN BENEFICIAL OWNERS ANDAND MANAGEMENT

Principal Stockholders

The following table sets forth certain information regarding the ownership of the Company’s Common Stock as of Marchthe August 31, 2016,2018, by: (i) each director and nominee for director, (ii) each of our named executive officers, (iii) all executive officers and directors of the Company as a group, and (iv) all those known by the Company to be beneficial owners of more than five percent of its Common Stock. Unless otherwise noted below, the address of each beneficial owner listed on the table is c/o ARCA biopharma, Inc., 11080 CirclePoint Road, Suite 140, Westminster, Colorado, 80020.

On September 3, 2015, the Company completed a 1-for-7 reverse split of its Common Stock. All share amounts throughout this proxy statement have been adjusted retroactively to reflect the effects of this action.

We have determined beneficial ownership in accordance with the rules of the Securities and Exchange Commission, or the SEC. Except as indicated by the footnotes below, we believe, based on the information furnished to us, that the persons and entities named in the table below have sole voting and investment power with respect to all shares of Common Stock that they beneficially own, subject to applicable community property laws. The table is based upon information supplied by officers, directors and principal stockholders and Schedules 13G or 13D, Form 4s or other ownership reports filed with the SEC. For purposes of this table, certain of our outstanding warrants that may be exercisable for fractional shares have been rounded down to the nearest whole number.

In computing the number of shares of Common Stock beneficially owned by a person and the percentage ownership of that person, we deemed outstanding shares of Common Stock subject to options, restricted stock units, or warrants held by that person that are currently exercisable or exercisable within 60 days of MarchAugust 31, 2016.2018. We did not deem these shares outstanding, however, for the purpose of computing the percentage ownership of any other person.

The percentages below are based on 9,056,64713,923,825 shares of our Common Stock outstanding as of MarchAugust 31, 2016.2018.

30.

14

31.

32.

SECTION 16(A) BENEFICIAL OWNERSHIP REPORTING COMPLIANCE

Section 16 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”) requires the Company’s directors and executive officers, and persons who own more than 10% of its Common Stock, to file with the SEC initial reports of ownership and reports of changes in ownership of Common Stock of the Company. Such persons are required by SEC regulation to furnish us with copies of all Section 16(a) forms that they file.

To the Company’s knowledge, based solely upon its review of the copies of such reports furnished to it and written representations that no other reports were required, during the fiscal year ended December 31, 2015, all Section 16(a) filing requirements applicable to its officers, directors and ten percent beneficial owners were complied with.

33.

EXECUTIVE OFFICERS

Set forth below is information regarding each of the executive officers as of March 31, 2016.

Michael R. Bristow, M.D., Ph.D. See Mr. Bristow’s biography in Proposal Number 1 – Election of Directors.

Brian L. Selby. Mr. Selby has served as the Company’s Vice President, Finance and Chief Accounting Officer since December 2014. Previously, Mr. Selby served as the Company’s Controller from 2007 to 2014. Prior to joining the Company, Mr. Selby served as the Controller for Myogen, Inc., a publicly traded pharmaceutical company subsequently acquired by Gilead, from 2004 to 2007. Prior to Myogen, Mr. Selby served as the Controller for several private and publicly traded companies and earlier in his career was an auditor with Deloitte & Touche, LLP. Mr. Selby received his M.S. in Accounting from the University of Colorado and received his B.S., in Business Administration and Finance from Colorado State University, and is a certified public accountant.

Thomas A. Keuer. Mr. Keuer has served as the Company’s Chief Operating Officer since December 2014. Mr. Keuer served as the Company’s Executive Vice President, Pharmaceutical Operations from 2006 to 2014. Prior to joining the Company, Mr. Keuer served as the SVP of Operations for Insmed, Inc. from 2004 to 2006. Prior to Insmed, Mr. Keuer served as the VP of Engineering for Baxter Healthcare from 1998 to 2004. Prior to Baxter, Mr. Keuer served as the VP of Operations for Somatogen, Inc. Mr. Keuer received his M.S. in Biochemical Engineering from Rice University and received his B.S. in Chemical Engineering from the University of Texas, Austin.

Christopher D. Ozeroff. Mr. Ozeroff is a co-founder of ARCA. Mr. Ozeroff has served as the Company’s Senior Vice President, General Counsel and Secretary since 2009, has served as the Company’s General Counsel and Secretary since the Company’s founding, and has also served as Executive Vice President, Business Development from 2004 to 2009. Prior to joining the Company, Mr. Ozeroff was a partner with the law firm of Hogan & Hartson L.L.P., where he practiced in such areas as finance, acquisitions, public offerings, and licensing. Mr. Ozeroff completed his undergraduate degree at Stanford University and his law degree at the University of Chicago Law School.

34.

Executive Compensation

The following table shows for the fiscal years ended December 31, 2015 and/or December 31, 2014, compensation awarded to, paid to, or earned by the Company’s principal executive officer and its other named executive officers as of December 31, 2015, collectively, the Named Executive Officers:

SUMMARY COMPENSATION TABLEFOR FISCAL 2015AND 2014

15

35.

Appendix ANNEXA-1

CERTIFICATE OF AMENDMENT

OF

AMENDED AND RESTATED CERTIFICATE OF INCORPORATION

OF

ARCA BIOPHARMA, INC.

ARCA BIOPHARMABIOPHARMA, INC., a corporation organized and existing under and by virtue of the General Corporation Law of the State of Delaware (the “DGCL”), does hereby certify:

AFMENDEDAND RESTATED 2013 EQUITY INCENTIVE PLAN

ORIGINALLY ADOPTEDBYTHE BOARDOF DIRECTORSIRST: JULY 26, 2013

ORIGINALLY APPROVEDBYTHE STOCKHOLDERS: SEPTEMBER 17, 2013

AMENDEDBYTHE BOARDOF DIRECTORS: APRIL 20, 2016

APPROVEDBYTHE STOCKHOLDERS: JUNE __, 2016

(a)        Eligible Award Recipients. Employees, Directors and Consultants are eligible to receive Awards.

(b)        Available Awards.               The Plan provides for the grantname of the following Awards: (i) Incentive Stock Options, (ii) Nonstatutory Stock Options, (iii) Stock Appreciation Rights (iv) Restricted Stock Awards, (v) Restricted Stock Unit Awards, (vi) Performance Stock Awards, (vii) Performance Cash Awards, and (viii) Other Stock Awards.corporation is ARCA biopharma, Inc. (the “Corporation”).

(c)        Purpose.SECOND:           The Plan, throughdate of filing of its original Certificate of Incorporation with the grantingSecretary of Awards, is intended to help the Company secure and retain the services of eligible award recipients, provide incentives for such persons to exert maximum efforts for the successState of the Company and any Affiliate, and provide a means by whichState of Delaware was March 16, 2004 under the eligible recipients may benefit from increases in value of the Common Stock.name “Nuvelo Merger Sub, Inc.”

(a)        Administration by Board.THIRD:              The Board will administer the Plan. The of Directors (the “Board may delegate administration”) of the Plan to a Committee or Committees, as providedCorporation, acting in Section 2(c).

(b)        Powers of Board.The Board will have the power, subject to, and within the limitations of, the express provisions of the Plan:

(i)        To determine: (A) who will be granted Awards; (B) when and how each Award will be granted; (C) what type of Award will be granted; (D) the provisions of each Award (which need not be identical), including when a person will be permitted to exercise or otherwise receive cash or Common Stock under the Award; (E) the number of shares of Common Stock subject to, or the cash value of, an Award; and (F) the Fair Market Value applicable to a Stock Award.

(ii)        To construe and interpret the Plan and Awards granted under it, and to establish, amend and revoke rules and regulations for administration of the Plan and Awards. The Board, in the exercise of these powers, may correct any defect, omission or inconsistency in the Plan or in any Award Agreement or in the written terms of a Performance Cash Award, in a manner and to the extent it will deem necessary or expedient to make the Plan or Award fully effective.

1.

(iii)        To settle all controversies regarding the Plan and Awards granted under it.

(iv)        To accelerate, in whole or in part, the time at which an Award may be exercised or vest (or at which cash or shares of Common Stock may be issued).

(v)        To suspend or terminate the Plan at any time. Except as otherwise provided in the Plan or an Award Agreement, suspension or termination of the Plan will not materially impair a Participant’s rights under his or her then-outstanding Award without his or her written consent except as provided in subsection (viii) below.

(vi)        To amend the Plan in any respect the Board deems necessary or advisable, including, without limitation, by adopting amendments relating to Incentive Stock Options and certain nonqualified deferred compensation under Section 409A of the Code and/or to bring the Plan or Awards granted under the Plan compliant with the requirements for Incentive Stock Options or exempt from or compliant with the requirements for nonqualified deferred compensation under Section 409A of the Code, subject to the limitations, if any, of applicable law. If required by applicable law or listing requirements, and except as provided in Section 9(a) relating to Capitalization Adjustments, the Company will seek stockholder approval of any amendment of the Plan that (A) materially increases the number of shares of Common Stock available for issuance under the Plan, (B) materially expands the class of individuals eligible to receive Awards under the Plan, (C) materially increases the benefits accruing to Participants under the Plan, (D) materially reduces the price at which shares of Common Stock may be issued or purchased under the Plan, (E) materially extends the term of the Plan, or (F) materially expands the types of Awards available for issuance under the Plan. Except as otherwise provided in the Plan or an Award Agreement, no amendment of the Plan will materially impair a Participant’s rights under an outstanding Award without the Participant’s written consent.

(vii)        To submit any amendment to the Plan for stockholder approval, including, but not limited to, amendments to the Plan intended to satisfy the requirements of (A) Section 162(m) of the Code regarding the exclusion of performance-based compensation from the limit on corporate deductibility of compensation paid to Covered Employees, (B) Section 422 of the Code regarding “incentive stock options” or (C) Rule 16b-3.

(viii)        To approve forms of Award Agreements for use under the Plan and to amend the terms of any one or more Awards, including, but not limited to, amendments to provide terms more favorable to the Participant than previously provided in the Award Agreement, subject to any specified limits in the Plan that are not subject to Board discretion; provided however, that a Participant’s rights under any Award will not be impaired by any such amendment unless (A) the Company requests the consent of the affected Participant, and (B) such Participant consents in writing. Notwithstanding the foregoing, (1) a Participant’s rights will not be deemed to have been impaired by any such amendment if the Board, in its sole discretion, determines that the amendment, taken as a whole, does not materially impair the Participant’s rights, and (2) subject to the limitations of applicable law, if any, the Board may amend the terms of any one or more Awards without the affected Participant’s consent (A) to maintain the qualified status of the Award as an Incentive Stock Option under Section 422 of the Code; (B) to change the terms of an Incentive Stock Option, if such change results in impairment of the Award solely because it impairs the qualified status of the Award as an Incentive Stock

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Option under Section 422 of the Code; (C) to clarify the manner of exemption from, or to bring the Award into compliance with, Section 409A of the Code; or (D) to comply with other applicable laws or listing requirements.

(ix)        Generally, to exercise such powers and to perform such acts as the Board deems necessary or expedient to promote the best interests of the Company and that are not in conflictaccordance with the provisions of Sections 141 and 242 of the Plan or Awards.DGCL, adopted resolutions amending its Amended and Restated Certificate of Incorporation, as amended, as follows:

(x)1.                         To adopt such proceduresArticle IV of the Amended and sub-plans as are necessary or appropriateRestated Certificate of Incorporation of the Corporation is hereby amended to permit participationadd the following provisions in the Plan by Employees, Directors or Consultants who are foreign nationals or employed outside the United States (provided that Board approval will not be necessary for immaterial modificationstheir entirety to the Plan or any Award Agreement that are required for complianceexisting provisions of Article IV:

“Effective at 5:01 p.m. Eastern time, on the date of the filing of this Certificate of Amendment to the Amended and Restated Certificate of Incorporation with the lawsSecretary of State of the relevant foreign jurisdiction).

(xi)        To effect, withState of Delaware (the “Effective Time”), the consent of any adversely affected Participant, (A) the reductionshares of the exercise, purchase or strike price of any outstanding Stock Award; (B) the cancellation of any outstanding Stock Award and the grant in substitution therefor of a new (1) Option or SAR, (2) Restricted Stock Award, (3) Restricted Stock Unit Award, (4) Other Stock Award, (5) cash award and/or (6) award of other valuable consideration determined by the Board, in its sole discretion, with any such substituted award (x) covering the same or a different number of shares ofCorporation’s Common Stock, as the cancelled Stock Awardpar value $0.001 per share, issued and (y) granted under the Plan or another equity or compensatory plan of the Company; or (C) any other action that is treated as a repricing under generally accepted accounting principles.

(c)      Delegation to Committee.

(i)        General. The Board may delegate some or all of the administration of the Plan to a Committee or Committees. If administration of the Plan is delegated to a Committee, the Committee will have, in connection with the administration of the Plan, the powers theretofore possessed by the Board that have been delegated to the Committee, including the power to delegate to a subcommittee of the Committee any of the administrative powers the Committee is authorized to exercise (and references in this Plan to the Board will thereafter be to the Committee or subcommittee, as applicable). Any delegation of administrative powers will be reflected in resolutions, not inconsistent with the provisions of the Plan, adopted from time to time by the Board or Committee (as applicable). The Board may retain the authority to concurrently administer the Plan with the Committee and may, at any time, revest in the Board some or all of the powers previously delegated.

(ii)        Section 162(m) and Rule 16b-3 Compliance. The Committee may consist solely of two or more Outside Directors, in accordance with Section 162(m) of the Code, or solely of two or more Non-Employee Directors, in accordance with Rule 16b-3.

(d)        Delegation to an Officer. The Board may delegate to one (1) or more Officers the authority to do one or both of the following (i) designate Employees who are not Officers to be recipients of Options and SARs (and, to the extent permitted by applicable law, other Stock Awards) and, to the extent permitted by applicable law, the terms of such Awards, and (ii) determine the number of shares of Common Stock to be subject to such Stock Awards granted to

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such Employees;provided,however, that the Board resolutions regarding such delegation will specify the total number of shares of Common Stock that may be subject to the Stock Awards granted by such Officer and that such Officer may not grant a Stock Award to himself or herself. Any such Stock Awards will be granted on the form of Stock Award Agreement most recently approved for use by the Committee or the Board, unless otherwise provided in the resolutions approving the delegation authority. The Board may not delegate authority to an Officer who is acting solely in the capacity of an Officer (and not also as a Director) to determine the Fair Market Value pursuant to Section 13(y)(iii) below.

(e)        Effect of Board’s Decision. All determinations, interpretations and constructions made by the Board in good faith will not be subject to review by any person and will be final, binding and conclusive on all persons.

(a)        Share Reserve.Subject to Section 9(a) relating to Capitalization Adjustments, the aggregate number of shares of Common Stock that may be issued pursuant to Stock Awards from and after the Effective Date will not exceed 1,259,675 shares, which is equal to the sum of (i) 47,654 shares remaining available for grant under the Planoutstanding immediately prior to the Effective Date of its amendmentTime and restatement; (ii) an additional 1,000,000 newly reserved shares; and (iii) any shares subject to Stock Awards granted under the Plan prior to the Effective Date of its amendment and restatement, which become available for grant under the Plan from time to time pursuant to Section 3(b) hereof due to their reversion to the Plan, up to a maximum of 212,021 shares (such aggregate number of shares described in (i), (ii) and (iii) above, the “Share Reserve”). For clarity, the Share Reserve in this Section 3 is a limitation on the number of shares of Common Stock that may be issued pursuant to the Plan. Accordingly, this Section 3 does not limit the granting of Stock Awards except as provided in Section 7(a). Shares may be issued in connection with a merger or acquisition as permitted by NASDAQ Listing Rule 5635(c) or, if applicable, NYSE Listed Company Manual Section 303A.08, AMEX Company Guide Section 711 or other applicable rule, and such issuance will not reduce the number of shares available for issuance under the Plan.

(b)        Reversion of Shares to the Share Reserve. If a Stock Award or any portion thereof (i) expires or otherwise terminates without all of the shares covered by such Stock Award having been issued or (ii) is settled in cash (i.e., the Participant receives cash rather than stock), such expiration, termination or settlement will not reduce (or otherwise offset) the number of shares of Common Stock that may be available for issuance under the Plan. If any shares of Common Stock issued pursuant to a Stock Award are forfeited back to or repurchased by the Company because of the failure to meet a contingency or condition required to vest such shares in the Participant, then the shares that are forfeited or repurchased will revert to and again become available for issuance under the Plan. Any shares reacquired by the Company in satisfaction of tax withholding obligations on a Stock Award or as consideration for the exercise or purchase price of a Stock Award will again become available for issuance under the Plan.

(c)        Incentive Stock Option Limit. Subject to the provisions of Section 9(a) relating to Capitalization Adjustments, the aggregate maximum number of shares of Common Stock that may be issued pursuant to the exercise of Incentive Stock Options is 1,259,675.

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(d)        Section 162(m) Limitations. Subject to the provisions of Section 9(a) relating to Capitalization Adjustments, at such time as the Company may be subject to the applicable provisions of Section 162(m) of the Code, the following limitations shall apply.

(i)        A maximum of three hundred thousand (300,000) shares of Common Stock subject to Options, SARs and Other Stock Awards whose value is determined by reference to an increase over an exercise or strike price of at least 100% of the Fair Market Value on the date the Stock Award is granted may be granted to any one Participant during any one calendar year, provided, however, that the Company may make an additional one-time grant to any newly-hired Employee of an Option, SAR or Other Stock Award for the purchase of up to an additional one hundred thousand (100,000) shares of Common Stock. An Option which is canceled (or a freestanding SAR as to which the exercise price is reduced to reflect a reduction in the Fair Market Value of the Common Stock) in the same fiscal year of the Company in which it was granted shall continue to be counted against such limit for such fiscal year. Notwithstanding the foregoing, if any additional Options, SARs or Other Stock Awards whose value is determined by reference to an increase over an exercise or strike price of at least one hundred percent (100%) of the Fair Market Value on the date the Stock Award are granted to any Participant during any calendar year, compensation attributable to the exercise of such additional Stock Awards will not satisfy the requirements to be considered “qualified performance-based compensation” under Section 162(m) of the Code unless such additional Stock Award is approved by the Company’s stockholders.

(ii)        A maximum of fifty thousand (50,000) shares of Common Stock may be granted as a Restricted Stock Award or Restricted Stock Unit Award to any one Participant during any one calendar year, subject to vesting conditions based on the attainment during the Performance Period of the Performance Goals, provided, however, that the Company may make an additional one-time grant to any newly-hired Employee of a Restricted Stock Award or Restricted Stock Unit Award of up to an additional fifteen thousand (15,000) shares of Common Stock.

(iii)        A maximum of one hundred thousand (100,000) shares of Common Stock subject to Performance Stock Awards may be granted to any one Participant during any one calendar year (whether the grant, vesting or exercise is contingent upon the attainment during the Performance Period of the Performance Goals).

(iv)        A maximum of $2,000,000 may be granted as a Performance Cash Award to any one Participant during any one calendar year.

(e)        Limitation on Grants to Non-Employee Directors. The maximum number of shares of Common Stock subject to Stock Awards granted under the Plan or otherwise during any one fiscal year to any Non-Employee Director, taken together with any cash fees paid by the Company to such Non-Employee Director during such fiscal year for service on the Board, will not exceed $300,000 in total value (calculating the value of any such Stock Awards based on the grant date fair value of such Stock Awards for financial reporting purposes). The Board may make exceptions to the applicable limit in this Section 3(e) for individual Non-Employee Directors in extraordinary circumstances (for example, to compensate such individual for interim service in the capacity of an officer of the Company), as the Board may determine in its

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discretion, provided that the Non-Employee Director receiving such additional compensation may not participate in the decision to award such compensation or in other compensation decisions involving Non-Employee Directors.

(f)        Source of Shares. The stock issuable under the Plan will be shares of authorized but unissued or reacquired Common Stock, including shares repurchased by the Company on the open market or otherwise.

(a)        Eligibility for Specific Stock Awards. Incentive Stock Options may be granted only to employees of the Company or a “parent corporation” or “subsidiary corporation” thereof (as such terms are defined in Sections 424(e) and 424(f) of the Code). Stock Awards other than Incentive Stock Options may be granted to Employees, Directors and Consultants;provided, however, that Stock Awards may not be granted to Employees, Directors and Consultants who are providing Continuous Service only to any “parent” of the Company, as such term is defined in Rule 405 of the Securities Act, unless (i) the stock underlying such Stock Awards is treated as “service recipient stock” under Section 409A of the Code (for example, because the Stock Awards are granted pursuant to a corporate transaction such as a spin off transaction), (ii) the Company, in consultation with its legal counsel, has determined that such Stock Awards are otherwise exempt from Section 409A of the Code, or (iii) the Company, in consultation with its legal counsel, has determined that such Stock Awards comply with the distribution requirements of Section 409A of the Code.

(b)        Ten Percent Stockholders. A Ten Percent Stockholder will not be granted an Incentive Stock Option unless the exercise price of such Option is at least 110% of the Fair Market Value on the date of grant and the Option is not exercisable after the expiration of five years from the date of grant.

Each Option or SAR will be in such form and will contain such terms and conditions as the Board deems appropriate. All Options will be separately designated Incentive Stock Options or Nonstatutory Stock Options at the time of grant, and, if certificates are issued, a separate certificate or certificates will be issued for shares of Common Stock purchased on exercise of each type of Option. If an Option is not specifically designated as an Incentive Stock Option, or if an Option is designated as an Incentive Stock Option but some portion or all of the Option fails to qualify as an Incentive Stock Option under the applicable rules, then the Option (or portion thereof) will be a Nonstatutory Stock Option. The provisions of separate Options or SARs need not be identical;provided, however, that each Award Agreement will conform to (through incorporation of provisions hereof by reference in the applicable Award Agreement or otherwise) the substance of each of the following provisions:

(a)        Term. Subject to the provisions of Section 4(b) regarding Ten Percent Stockholders, no Option or SAR will be exercisable after the expiration of ten years from the date of its grant or such shorter period specified in the Award Agreement.

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(b)        Exercise Price. Subject to the provisions of Section 4(b) regarding Ten Percent Stockholders, the exercise or strike price of each Option or SAR will be not less than 100% of the Fair Market Value of the Common Stock subject to the Option or SAR on the date the Award is granted. Notwithstanding the foregoing, an Option or SAR may be granted with an exercise or strike price lower than 100% of the Fair Market Value of the Common Stock subject to the Award if such Award is granted pursuant to an assumption of or substitution for another option or stock appreciation right pursuant to a Corporate Transaction and in a manner consistent with the provisions of Section 409A and, if applicable, Section 424(a) of the Code. Each SAR will be denominated in shares of Common Stock equivalents.

(c)        Purchase Price for Options. The purchase price of Common Stock acquired pursuant to the exercise of an Option may be paid, to the extent permitted by applicable law and as determined by the Board in its sole discretion, by any combination of the methods of payment set forth below. The Board will have the authority to grant Options that do not permit all of the following methods of payment (or otherwise restrict the ability to use certain methods) and to grant Options that require the consent of the Company to use a particular method of payment. The permitted methods of payment are as follows:

(i)        by cash, check, bank draft or money order payable to the Company;

(ii)        pursuant to a program developed under Regulation T as promulgated by the Federal Reserve Board that, prior to the issuance of the stock subject to the Option, results in either the receipt of cash (or check) by the Company or the receipt of irrevocable instructions to pay the aggregate exercise price to the Company from the sales proceeds;

(iii)        by delivery to the Company (either by actual delivery or attestation) of shares of Common Stock;

(iv)        if an Option is a Nonstatutory Stock Option, by a “net exercise” arrangement pursuant to which the Company will reduce the number of shares of Common Stock issuable upon exercise by the largest whole number of shares with a Fair Market Value that does not exceed the aggregate exercise price; provided, however, that the Company will accept a cash or other payment from the Participant to the extent of any remaining balance of the aggregate exercise price not satisfied by such reduction in the number of whole shares to be issued. Shares of Common Stock will no longer be subject to an Option and will not be exercisable thereafter to the extent that (A) shares issuable upon exercise are reduced to pay the exercise price pursuant to the “net exercise,” (B) shares are delivered to the Participant as a result of such exercise, and (C) shares are withheld to satisfy tax withholding obligations; or

(v)        in any other form of legal consideration that may be acceptable to the Board and specified in the applicable Award Agreement.

(d)        Exercise and Payment of a SAR. To exercise any outstanding SAR, the Participant must provide written notice of exercise to the Company in compliance with the provisions of the Stock Appreciation Right Agreement evidencing such SAR. The appreciation distribution payable on the exercise of a SAR will be not greater than an amount equal to the excess of (A) the aggregate Fair Market Value (on the date of the exercise of the SAR) of a

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number of shares of Common Stock equal to the number of Common Stock equivalents in which the Participant is vested under such SAR, and with respect to which the Participant is exercising the SAR on such date, over (B) the aggregate strike price of the number of Common Stock equivalents with respect to which the Participant is exercising the SAR on such date. The appreciation distribution may be paid in Common Stock, in cash, in any combination of the two or in any other form of consideration, as determined by the Board and contained in the Award Agreement evidencing such SAR.

(e)        Transferability of Options and SARs. The Board may, in its sole discretion, impose such limitations on the transferability of Options and SARs as the Board will determine. In the absence of such a determination by the Board to the contrary, the following restrictions on the transferability of Options and SARs will apply:

(i)        Restrictions on Transfer. An Option or SAR will not be transferable except by will or by the laws of descent and distribution (or pursuant to subsections (ii) and (iii) below), and will be exercisable during the lifetime of the Participant only by the Participant. The Board may permit transfer of the Option or SAR in a manner that is not prohibited by applicable tax and securities laws. Except as explicitly provided herein, neither an Option nor a SAR may be transferred for consideration.

(ii)        Domestic Relations Orders. Subject to the approval of the Board or a duly authorized Officer, an Option or SAR may be transferred pursuant to the terms of a domestic relations order, official marital settlement agreement or other divorce or separation instrument as permitted by Treasury Regulations Section 1.421-1(b)(2). If an Option is an Incentive Stock Option, such Option may be deemed to be a Nonstatutory Stock Option as a result of such transfer.

(iii)        Beneficiary Designation. Subject to the approval of the Board or a duly authorized Officer, a Participant may, by delivering written notice to the Company, in a form approved by the Company (or the designated broker), designate a third party who, on the death of the Participant, will thereafter be entitled to exercise the Option or SAR and receive the Common Stock or other consideration resulting from such exercise. In the absence of such a designation, the executor or administrator of the Participant’s estate will be entitled to exercise the Option or SAR and receive the Common Stock or other consideration resulting from such exercise. However, the Company may prohibit designation of a beneficiary at any time, including due to any conclusion by the Company that such designation would be inconsistent with the provisions of applicable laws.

(f)        Vesting Generally.The total number of shares of Common Stock subject to an Option or SAR may vest and become exercisable in periodic installments that may or may not be equal. The Option or SAR may be subject to such other terms and conditions on the time or times when it may or may not be exercised (which may be based on the satisfaction of Performance Goals or other criteria) as the Board may deem appropriate. The vesting provisions of individual Options or SARs may vary. The provisions of this Section 5(f) are subject to any Option or SAR provisions governing the minimum number of shares of Common Stock as to which an Option or SAR may be exercised.

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(g)        Termination of Continuous Service. Except as otherwise provided in the applicable Award Agreement or other agreement between the Participant and the Company, if a Participant’s Continuous Service terminates (other than for Cause and other than upon the Participant’s death or Disability), the Participant may exercise his or her Option or SAR (to the extent that the Participant was entitled to exercise such Award as of the date of termination of Continuous Service) within the period of time ending on the earlier of (i) the date three (3) months following the termination of the Participant’s Continuous Service (or such longer or shorter period specified in the applicable Award Agreement), and (ii) the expiration of the term of the Option or SAR as set forth in the Award Agreement. If, after termination of Continuous Service, the Participant does not exercise his or her Option or SAR (as applicable) within the applicable time frame, the Option or SAR will terminate.

(h)        Extension of Termination Date. Except as otherwise provided in the applicable Award Agreement or other agreement between the Participant and the Company, if the exercise of an Option or SAR following the termination of the Participant’s Continuous Service (other than for Cause and other than upon the Participant’s death or Disability) would be prohibited at any time solely because the issuance of shares of Common Stock would violate the registration requirements under the Securities Act, then the Option or SAR will terminate on the earlier of (i) the expiration of a total period of time (that need not be consecutive) equal to the applicable post termination exercise period after the termination of the Participant’s Continuous Service during which the exercise of the Option or SAR would not be in violation of such registration requirements, and (ii) the expiration of the term of the Option or SAR as set forth in the applicable Award Agreement. In addition, unless otherwise provided in a Participant’s Award Agreement, if the sale of any Common Stock received on exercise of an Option or SAR following the termination of the Participant’s Continuous Service (other than for Cause) would violate the Company’s insider trading policy, then the Option or SAR will terminate on the earlier of (i) the expiration of a period of months (that need not be consecutive) equal to the applicable post-termination exercise period after the termination of the Participant’s Continuous Service during which the sale of the Common Stock received upon exercise of the Option or SAR would not be in violation of the Company’s insider trading policy, or (ii) the expiration of the term of the Option or SAR as set forth in the applicable Award Agreement.

(i)        Disability of Participant. Except as otherwise provided in the applicable Award Agreement or other agreement between the Participant and the Company, if a Participant’s Continuous Service terminates as a result of the Participant’s Disability, the Participant may exercise his or her Option or SAR (to the extent that the Participant was entitled to exercise such Option or SAR as of the date of termination of Continuous Service), but only within such period of time ending on the earlier of (i) the date twelve (12) months following such termination of Continuous Service (or such longer or shorter period specified in the Award Agreement), and (ii) the expiration of the term of the Option or SAR as set forth in the Award Agreement. If, after termination of Continuous Service, the Participant does not exercise his or her Option or SAR within the applicable time frame, the Option or SAR (as applicable) will terminate.

(j)        Death of Participant. Except as otherwise provided in the applicable Award Agreement or other agreement between the Participant and the Company, if (i) a Participant’s Continuous Service terminates as a result of the Participant’s death, or (ii) the Participant dies within the period (if any) specified in the Award Agreement for exercisability after the

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termination of the Participant’s Continuous Service for a reason other than death, then the Option or SAR may be exercised (to the extent the Participant was entitled to exercise such Option or SAR as of the date of death) by the Participant’s estate, by a person who acquired the right to exercise the Option or SAR by bequest or inheritance or by a person designated to exercise the Option or SAR upon the Participant’s death, but only within the period ending on the earlier of (i) the date eighteen (18) months following the date of death (or such longer or shorter period specified in the Award Agreement), and (ii) the expiration of the term of such Option or SAR as set forth in the Award Agreement. If, after the Participant’s death, the Option or SAR is not exercised within the applicable time frame, the Option or SAR (as applicable) will terminate.

(k)        Termination for Cause. Except as explicitly provided otherwise in a Participant’s Award Agreement or other individual written agreement between the Company or any Affiliate and the Participant, if a Participant’s Continuous Service is terminated for Cause, the Option or SAR will terminate immediately upon such Participant’s termination of Continuous Service, and the Participant will be prohibited from exercising his or her Option or SAR from and after the date of such termination of Continuous Service.

(l)        Non-Exempt Employees. If an Option or SAR is granted to an Employee who is a non-exempt employee for purposes of the Fair Labor Standards Act of 1938, as amended, the Option or SAR will not be first exercisable for any shares of Common Stock until at least six (6) months following the date of grant of the Option or SAR (although the Award may vest prior to such date). Consistent with the provisions of the Worker Economic Opportunity Act, (i) if such non-exempt Employee dies or suffers a Disability, (ii) upon a Corporate Transaction in which such Option or SAR is not assumed, continued, or substituted, (iii) upon a Change in Control, or (iv) upon the Participant’s retirement (as such term may be defined in the Participant’s Award Agreement in another agreement between the Participant and the Company, or, if no such definition, in accordance with the Company’s then current employment policies and guidelines), the vested portion of any Options and SARs may be exercised earlier than six months following the date of grant. The foregoing provision is intended to operate so that any income derived by a non-exempt employee in connection with the exercise or vesting of an Option or SAR will be exempt from his or her regular rate of pay. To the extent permitted and/or required for compliance with the Worker Economic Opportunity Act to ensure that any income derived by a non-exempt employee in connection with the exercise, vesting or issuance of any shares under any other Stock Award will be exempt from the employee’s regular rate of pay, the provisions of this Section 5(l) will apply to all Stock Awards and are hereby incorporated by reference into such Stock Award Agreements.

(a)        Restricted Stock Awards. Each Restricted Stock Award Agreement will be in such form and will contain such terms and conditions as the Board will deem appropriate. To the extent consistent with the Company’s bylaws, at the Board’s election, shares of Common Stock underlying a Restricted Stock Award may be (x) held in book entry form subject to the Company’s instructions until any restrictions relating to the Restricted Stock Award lapse; or (y) evidenced by a certificate, which certificate will be held in such form and manner as determined by the Board. The terms and conditions of Restricted Stock Award Agreements may change from time to time, and the terms and conditions of separate Restricted Stock Award

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Agreements need not be identical. Each Restricted Stock Award Agreement will conform to (through incorporation of the provisions hereof by reference in the agreement or otherwise) the substance of each of the following provisions:

(i)        Consideration. A Restricted Stock Award may be awarded in consideration for (A) cash, check, bank draft or money order payable to the Company, (B) past services to the Company or an Affiliate, or (C) any other form of legal consideration (including future services) that may be acceptable to the Board, in its sole discretion, and permissible under applicable law.

(ii)        Vesting.Shares of Common Stock awarded under the Restricted Stock Award Agreement may be subject to forfeiture to the Company in accordance with a vesting schedule to be determined by the Board.

(iii)        Termination of Participant’s Continuous Service. If a Participant’s Continuous Service terminates, the Company may receive through a forfeiture condition or a repurchase right any or all of the shares of Common Stock held by the Participant as of the date of termination of Continuous Service under the terms of the Restricted Stock Award Agreement.

(iv)        Transferability. Rights to acquire shares of Common Stock under the Restricted Stock Award Agreement will be transferable by the Participant only upon such terms and conditions as are set forth in the Restricted Stock Award Agreement, as the Board will determine in its sole discretion, so long as Common Stock awarded under the Restricted Stock Award Agreement remains subject to the terms of the Restricted Stock Award Agreement.

(v)        Dividends. A Restricted Stock Award Agreement may provide that any dividends paid on Restricted Stock will be subject to the same vesting and forfeiture restrictions as apply to the shares subject to the Restricted Stock Award to which they relate.

(b)        Restricted Stock Unit Awards.Each Restricted Stock Unit Award Agreement will be in such form and will contain such terms and conditions as the Board will deem appropriate. The terms and conditions of Restricted Stock Unit Award Agreements may change from time to time, and the terms and conditions of separate Restricted Stock Unit Award Agreements need not be identical. Each Restricted Stock Unit Award Agreement will conform to (through incorporation of the provisions hereof by reference in the Agreement or otherwise) the substance of each of the following provisions:

(i)        Consideration. At the time of grant of a Restricted Stock Unit Award, the Board will determine the consideration, if any, to be paid by the Participant upon delivery of each share of Common Stock subject to the Restricted Stock Unit Award. The consideration to be paid (if any) by the Participant for each share of Common Stock subject to a Restricted Stock Unit Award may be paid in any form of legal consideration that may be acceptable to the Board, in its sole discretion, and permissible under applicable law.

(ii)        Vesting.At the time of the grant of a Restricted Stock Unit Award, the Board may impose such restrictions on or conditions to the vesting of the Restricted Stock Unit Award as it, in its sole discretion, deems appropriate.

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(iii)        Payment. A Restricted Stock Unit Award may be settled by the delivery of shares of Common Stock, their cash equivalent, any combination thereof or in any other form of consideration, as determined by the Board and contained in the Restricted Stock Unit Award Agreement.

(iv)        Additional Restrictions.At the time of the grant of a Restricted Stock Unit Award, the Board, as it deems appropriate, may impose such restrictions or conditions that delay the delivery of the shares of Common Stock (or their cash equivalent) subject to a Restricted Stock Unit Award to a time after the vesting of such Restricted Stock Unit Award.

(v)        Dividend Equivalents.Dividend equivalents may be credited in respect of shares of Common Stock covered by a Restricted Stock Unit Award, as determined by the Board and contained in the Restricted Stock Unit Award Agreement. At the sole discretion of the Board, such dividend equivalents may be converted into additional shares of Common Stock covered by the Restricted Stock Unit Award in such manner as determined by the Board. Any additional shares covered by the Restricted Stock Unit Award credited by reason of such dividend equivalents will be subject to all of the same terms and conditions of the underlying Restricted Stock Unit Award Agreement to which they relate.

(vi)        Termination of Participant’s Continuous Service.Except as otherwise provided in the applicable Restricted Stock Unit Award Agreement, such portion of the Restricted Stock Unit Award that has not vested will be forfeited upon the Participant’s termination of Continuous Service.

(c)        Performance Awards.

(i)        Performance Stock Awards. A Performance Stock Award is a Stock Award (covering a number of shares not in excess of that set forth in Section 3(d) above) that is payable (including that may be granted, vest or be exercised) contingent upon the attainment during a Performance Period of certain Performance Goals. A Performance Stock Award may, but need not, require the completion of a specified period of Continuous Service. The length of any Performance Period, the Performance Goals to be achieved during the Performance Period, and the measure of whether and to what degree such Performance Goals have been attained will be conclusively determined by the Committee (or, if not required for compliance with Section 162(m) of the Code, the Board), in its sole discretion. In addition, to the extent permitted by applicable law and the applicable Award Agreement, the Board or Committee may determine that cash may be used in payment of Performance Stock Awards.

(ii)        Performance Cash Awards. A Performance Cash Award is a cash award (for a dollar value not in excess of that set forth in Section 3(d) above) that is payable contingent upon the attainment during a Performance Period of certain Performance Goals. A Performance Cash Award may also require the completion of a specified period of Continuous Service. At the time of grant of a Performance Cash Award, the length of any Performance Period, the Performance Goals to be achieved during the Performance Period, and the measure of whether and to what degree such Performance Goals have been attained will be conclusively determined by the Committee (or, if not required for compliance with Section 162(m) of the Code, the Board), in its sole discretion. The Board or Committee may specify the form of payment of

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Performance Cash Awards, which may be cash or other property, or may provide for a Participant to have the option for his or her Performance Cash Award, or such portion thereof as the Board may specify, to be paid in whole or in part in cash or other property.

(iii)        Discretion. The Board and Committee retain the discretion to reduce or eliminate the compensation or economic benefit due upon attainment of Performance Goals and to define the manner of calculating the Performance Criteria it selects to use for a Performance Period. Partial achievement of the specified criteria may result in the payment or vesting corresponding to the degree of achievement as specified in the Stock Award Agreement or the written terms of a Performance Cash Award.

(iv)        Section 162(m) Compliance. Unless otherwise permitted in compliance with the requirements of Section 162(m) of the Code with respect to an Award intended to qualify as “performance-based compensation” thereunder, the Committee will establish the Performance Goals applicable to, and the formula for calculating the amount payable under, the Award no later than the earlier of (a) the date ninety (90) days after the commencement of the applicable Performance Period, and (b) the date on which 25% of the Performance Period has elapsed, and in any event at a time when the achievement of the applicable Performance Goals remains substantially uncertain. Prior to the payment of any compensation under an Award intended to qualify as “performance-based compensation” under Section 162(m) of the Code, the Committee will certify the extent to which any Performance Goals and any other material terms under such Award have been satisfied (other than in cases where such relate solely to the increase in the value of the Common Stock). Notwithstanding satisfaction of any completion of any Performance Goals, the number of shares of Common Stock, Options, cash or other benefits granted, issued, retainable and/or vested under an Award on account of satisfaction of such Performance Goals may be reduced by the Committee on the basis of such further considerations as the Committee, in its sole discretion, will determine.

(d)        Other Stock Awards. Other forms of Stock Awards valued in whole or in part by reference to, or otherwise based on, Common Stock, including the appreciation in value thereof (e.g., options or stock rights with an exercise price or strike price less than 100% of the Fair Market Value of the Common Stock at the time of grant) may be granted either alone or in addition to Stock Awards provided for under Section 5 and the preceding provisions of this Section 6. Subject to the provisions of the Plan, the Board will have sole and complete authority to determine the persons to whom and the time or times at which such Other Stock Awards will be granted, the number of shares of Common Stock (or the cash equivalent thereof) to be granted pursuant to such Other Stock Awards and all other terms and conditions of such Other Stock Awards.

(a)        Availability of Shares. The Company will keep available at all times the number of shares of Common Stock reasonably required to satisfy then-outstanding Awards.

(b)        Securities Law Compliance. The Company will seek to obtain from each regulatory commission or agency having jurisdiction over the Plan such authority as may be required to grant Stock Awards and to issue and sell shares of Common Stock upon exercise of

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the Stock Awards;provided, however, that this undertaking will not require the Company to register under the Securities Act the Plan, any Stock Award or any Common Stock issued or issuable pursuant to any such Stock Award. If, after reasonable efforts and at a reasonable cost, the Company is unable to obtain from any such regulatory commission or agency the authority that counsel for the Company deems necessary for the lawful issuance and sale of Common Stock under the Plan, the Company will be relieved from any liability for failure to issue and sell Common Stock upon exercise of such Stock Awards unless and until such authority is obtained. A Participant will not be eligible for the grant of an Award or the subsequent issuance of cash or Common Stock pursuant to the Award if such grant or issuance would be in violation of any applicable securities law.

(c)        No Obligation to Notify or Minimize Taxes. The Company will have no duty or obligation to any Participant to advise such holder as to the time or manner of exercising such Stock Award. Furthermore, the Company will have no duty or obligation to warn or otherwise advise such holder of a pending termination or expiration of an Award or a possible period in which the Award may not be exercised. The Company has no duty or obligation to minimize the tax consequences of an Award to the holder of such Award.

(a)        Use of Proceeds from Sales of Common Stock. Proceeds from the sale of shares of Common Stock pursuant to Awards will constitute general funds of the Company.

(b)        Corporate Action Constituting Grant of Awards. Corporate action constituting a grant by the Company of an Award to any Participant will be deemed completed as of the date of such corporate action, unless otherwise determined by the Board, regardless of when the instrument, certificate, or letter evidencing the Award is communicated to, or actually received or accepted by, the Participant. In the event that the corporate records (e.g., Board consents, resolutions or minutes) documenting the corporate action constituting the grant contain terms (e.g., exercise price, vesting schedule or number of shares) that are inconsistent with those in the Award Agreement or related grant documents as a result of a clerical error in the papering of the Award Agreement or related grant documents, the corporate records will control and the Participant will have no legally binding right to the incorrect term in the Award Agreement or related grant documents.

(c)        Stockholder Rights. No Participant will be deemed to be the holder of, or to have any of the rights of a holder with respect to, any shares of Common Stock subject to an Award unless and until (i) such Participant has satisfied all requirements for exercise of, or the issuance of shares under, the Award pursuant to its terms, and (ii) the issuance of the Common Stock subject to such Award has been entered into the books and records of the Company.

(d)        No Employment or Other Service Rights. Nothing in the Plan, any Award Agreement or any other instrument executed thereunder or in connection with any Award granted pursuant thereto will confer upon any Participant any right to continue to serve the Company or an Affiliate in the capacity in effect at the time the Award was granted or will affect the right of the Company or an Affiliate to terminate (i) the employment of an Employee with or without notice and with or without cause, (ii) the service of a Consultant pursuant to the terms of

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such Consultant’s agreement with the Company or an Affiliate, or (iii) the service of a Director pursuant to the bylaws of the Company or an Affiliate, and any applicable provisions of the corporate law of the state in which the Company or the Affiliate is incorporated, as the case may be.

(e)        Change in Time Commitment. In the event a Participant’s regular level of time commitment in the performance of his or her services for the Company and any Affiliates is reduced (for example, and without limitation, if the Participant is an Employee of the Company and the Employee has a change in status from a full-time Employee to a part-time Employee or takes an extended leave of absence) after the date of grant of any Award to the Participant, the Board has the right in its sole discretion to (x) make a corresponding reduction in the number of shares or cash amount subject to any portion of such Award that is scheduled to vest or become payable after the date of such change in time commitment, and (y) in lieu of or in combination with such a reduction, extend the vesting or payment schedule applicable to such Award. In the event of any such reduction, the Participant will have no right with respect to any portion of the Award that is so reduced.

(f)        Incentive Stock Option Limitations. To the extent that the aggregate Fair Market Value (determined at the time of grant) of Common Stock with respect to which Incentive Stock Options are exercisable for the first time by any Optionholder during any calendar year (under all plans of the Company and any Affiliates) exceeds $100,000 (or such other limit established in the Code) or otherwise does not comply with the rules governing Incentive Stock Options, the Options or portions thereof that exceed such limit (according to the order in which they were granted) or otherwise do not comply with the rules will be treated as Nonstatutory Stock Options, notwithstanding any contrary provision of the applicable Option Agreement(s).

(g)        Investment Assurances. The Company may require a Participant, as a condition of exercising or acquiring Common Stock under any Award, (i) to give written assurances satisfactory to the Company as to the Participant’s knowledge and experience in financial and business matters and/or to employ a purchaser representative reasonably satisfactory to the Company who is knowledgeable and experienced in financial and business matters and that he or she is capable of evaluating, alone or together with the purchaser representative, the merits and risks of exercising the Award; and (ii) to give written assurances satisfactory to the Company stating that the Participant is acquiring Common Stock subject to the Award for the Participant’s own account and not with any present intention of selling or otherwise distributing the Common Stock. The foregoing requirements, and any assurances given pursuant to such requirements, will be inoperative if (A) the issuance of the shares upon the exercise or acquisition of Common Stock under the Award has been registered under a then currently effective registration statement under the Securities Act, or (B) as to any particular requirement, a determination is made by counsel for the Company that such requirement need not be met in the circumstances under the then applicable securities laws. The Company may, upon advice of counsel to the Company, place legends on stock certificates issued under the Plan as such counsel deems necessary or appropriate in order to comply with applicable securities laws, including, but not limited to, legends restricting the transfer of the Common Stock.

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(h)        Withholding Obligations. Unless prohibited by the terms of an Award Agreement, the Company may, in its sole discretion, satisfy any federal, state or local tax withholding obligation relating to an Award by any of the following means or by a combination of such means: (i) causing the Participant to tender a cash payment; (ii) withholding shares of Common Stock from the shares of Common Stock issued or otherwise issuableand held in the treasury of the Corporation immediately prior to the ParticipantEffective Time shall be combined into a smaller number of shares such that each 3 shares of issued and outstanding Common Stock immediately prior to the Effective Time are combined into one validly issued, fully paid and nonassessable share of Common Stock, par value $0.001 per share. Notwithstanding the immediately preceding sentence, no fractional shares shall be issued and, in connection withlieu thereof, upon surrender after the Award;provided, however,that noEffective Time of a certificate which formerly represented shares of Common Stock are withheld with a value exceeding the minimum amount of tax required to be withheld by law (or such lesser amount as may be necessary to avoid classification of the Stock Award as a liability for financial accounting purposes); (iii) withholding cash from an Award settled in cash; (iv) withholding payment from any amounts otherwise payable to the Participant; or (v) by such other method as may be set forth in the Award Agreement.

(i)        Electronic Delivery. Any reference herein to a “written” agreement or document will include any agreement or document delivered electronically, filed publicly at www.sec.gov (or any successor website thereto) or posted on the Company’s intranet (or other shared electronic medium controlled by the Company to which the Participant has access).

(j)        Deferrals. To the extent permitted by applicable law, the Board, in its sole discretion, may determine that the delivery of Common Stock or the payment of cash, upon the exercise, vesting or settlement of all or a portion of any Award may be deferred and may establish programs and procedures for deferral elections to be made by Participants. Deferrals by Participants will be made in accordance with Section 409A of the Code. Consistent with Section 409A of the Code, the Board may provide for distributions while a Participant is still an employee or otherwise providing services to the Company. The Board is authorized to make deferrals of Awards and determine when, and in what annual percentages, Participants may receive payments, including lump sum payments, following the Participant’s termination of Continuous Service, and implement such other terms and conditions consistent with the provisions of the Plan and in accordance with applicable law.

(k)        Compliance with Section 409A of the Code.Unless otherwise expressly provided for in an Award Agreement, the Plan and Award Agreements will be interpreted to the greatest extent possible in a manner that makes the Plan and the Awards granted hereunder exempt from Section 409A of the Code, and, to the extent not so exempt, in compliance with Section 409A of the Code. If the Board determines that any Award granted hereunder is not exempt from and is therefore subject to Section 409A of the Code, the Award Agreement evidencing such Award will incorporate the terms and conditions necessary to avoid the consequences specified in Section 409A(a)(1) of the Code, and to the extent an Award Agreement is silent on terms necessary for compliance, such terms are hereby incorporated by reference into the Award Agreement. Notwithstanding anything to the contrary in this Plan (and unless the Award Agreement specifically provides otherwise), if the shares of Common Stock are publicly traded, and if a Participant holding an Award that constitutes “deferred compensation” under Section 409A of the Code is a “specified employee” for purposes of Section 409A of the Code, no distribution or payment of any amount that is due because of a “separation from service” (as defined in Section 409A of the Code without regard to alternative definitions thereunder) will bewere issued or paid before the date that is six months following the date of such Participant’s “separation from service” or, if earlier, the date of the Participant’s death, unless such distribution or payment can be made in a manner that complies with Section 409A of

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the Code, and any amounts so deferred will be paid in a lump sum on the day after such six month period elapses, with the balance paid thereafter on the original schedule.

(l)        Clawback/Recovery. All Awards granted under the Plan will be subject to recoupment in accordance with any clawback policy that the Company is required to adopt pursuant to the listing standards of any national securities exchange or association on which the Company’s securities are listed or as is otherwise required by the Dodd-Frank Wall Street Reform and Consumer Protection Act or other applicable law. In addition, the Board may impose such other clawback, recovery or recoupment provisions in an Award Agreement as the Board determines necessary or appropriate, including but not limited to a reacquisition right in respect of previously acquired shares of Common Stock or other cash or property upon the occurrence of an event constituting Cause. No recovery of compensation under such a clawback policy will be an event giving rise to a right to resign for “good reason” or “constructive termination” (or similar term) under any agreement with the Company.

(a)        Capitalization Adjustments. In the event of a Capitalization Adjustment, the Board will appropriately and proportionately adjust: (i) the class(es) and maximum number of securities subject to the Plan pursuant to Section 3, (ii) the class(es) and maximum number of securities that may be issued pursuant to the exercise of Incentive Stock Options pursuant to Section 3(c), (iii) the class(es) and maximum number of securities that may be awarded to any person pursuant to Sections 3(d), and (iv) the class(es) and number of securities and price per share of stock subject to outstanding Stock Awards. The Board will make such adjustments, and its determination will be final, binding and conclusive.

(b)        Dissolution. Except as otherwise provided in the Stock Award Agreement, in the event of a Dissolution of the Company, all outstanding Stock Awards (other than Stock Awards consisting of vested and outstanding shares of Common Stock not subject to a forfeiture condition or the Company’s right of repurchase) will terminate immediately prior to the completion of such Dissolution, and the sharesEffective Time, any person who would otherwise be entitled to a fractional share of Common Stock subject to the Company’s repurchase rights or subject to a forfeiture condition may be repurchased or reacquired by the Company notwithstanding the fact that the holder of such Stock Award is providing Continuous Service,provided, however, that the Board may, in its sole discretion, cause some or all Stock Awards to become fully vested, exercisable and/or no longer subject to repurchase or forfeiture (to the extent such Stock Awards have not previously expired or terminated) before the Dissolution is completed but contingent on its completion.

(c)        Corporate Transaction. The following provisions will apply to Stock Awards in the event of a Corporate Transaction unless otherwise provided in the instrument evidencing the Stock Award or any other written agreement between the Company or any Affiliate and the Participant or unless otherwise expressly provided by the Board at the time of grant of a Stock Award. In the event of a Corporate Transaction, then, notwithstanding any other provision of the Plan, the Board will take one or more of the following actions with respect to Stock Awards, contingent upon the closing or completion of the Corporate Transaction:

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(i)        arrange for the surviving corporation or acquiring corporation (or the surviving or acquiring corporation’s parent company) to assume or continue the Stock Award or to substitute a similar stock award for the Stock Award (including, but not limited to, an award to acquire the same consideration paid to the stockholders of the Company pursuant to the Corporate Transaction);

(ii)        arrange for the assignment of any reacquisition or repurchase rights held by the Company in respect of Common Stock issued pursuant to the Stock Award to the surviving corporation or acquiring corporation (or the surviving or acquiring corporation’s parent company);

(iii)        accelerate the vesting, in whole or in part, of the Stock Award (and, if applicable, the time at which the Stock Award may be exercised) to a date prior to the effective time of such Corporate Transaction as the Board will determine (or, if the Board will not determine such a date, to the date that is five days prior to the effective date of the Corporate Transaction), with, if so determined by the Board, such Stock Award terminating if not exercised (if applicable) at or prior to the effective time of the Corporate Transaction;

(iv)        arrange for the lapse, in whole or in part, of any reacquisition or repurchase rights held by the Company with respect to the Stock Award;

(v)        cancel or arrange for the cancellation of the Stock Award, to the extent not vested or not exercised prior to the effective time of the Corporate Transaction, in exchange for such cash consideration, if any, as the Board, in its sole discretion, may consider appropriate; and

(vi)        make a payment, in such form as may be determined by the Board equal to the excess, if any, of (A) the value of the property the Participant would have received upon the exercise of the Stock Award immediately prior to the effective time of the Corporate Transaction, over (B) any exercise price payable by such holder in connection with such exercise.

The Board need not take the same action or actions with respect to all Stock Awards or portions thereof or with respect to all Participants. The Board may take different actions with respect to the vested and unvested portions of a Stock Award.

(d)        Change in Control. A Stock Award may be subject to additional acceleration of vesting and exercisability upon or after a Change in Control as may be provided in the Stock Award Agreement for such Stock Award or as may be provided in any other written agreement between the Company or any Affiliate and the Participant, but in the absence of such provision, or action by the Board, no such acceleration will occur.

The Board may suspend or terminate the Plan at any time. No Incentive Stock Options may be granted after the tenth anniversary of the earlier of (i) the date the Plan is adopted by the Board (the “Adoption Date”), or (ii) the date the Plan is approved by the stockholders of the Company. No Awards may be granted under the Plan while the Plan is suspended or after it is terminated.

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This Plan will become effective on the Effective Date.

The law of the State of Colorado will govern all questions concerning the construction, validity and interpretation of this Plan, without regard to that state’s conflict of laws rules.

(a)        “Affiliate” means, at the time of determination, any “parent” or “subsidiary” of the Company as such terms are defined in Rule 405 of the Securities Act. The Board will have the authority to determine the time or times at which “parent” or “subsidiary” status is determined within the foregoing definition.

(b)        “Award” means a Stock Award or a Performance Cash Award.

(c)        “Award Agreement” means a written agreement between the Company and a Participant evidencing the terms and conditions of an Award.

(d)        “Board” means the Board of Directors of the Company.

(e)        “Capital Stock” means each and every class of common stock of the Company, regardless of the number of votes per share.

(f)        “Capitalization Adjustment” means any change that is made in, or other events that occur with respect to, the Common Stock subject to the Plan or subject to any Stock Award after the Adoption Date without the receipt of consideration by the Company through merger, consolidation, reorganization, recapitalization, reincorporation, stock dividend, dividend in property other than cash, large nonrecurring cash dividend, stock split, reverse stock split, liquidating dividend, combination of shares, exchange of shares, change in corporate structure or any similar equity restructuring transaction, as that term is used in Statement of Financial Accounting Standards Board Accounting Standards Codification Topic 718 (or any successor thereto). Notwithstanding the foregoing, the conversion of any convertible securities of the Company will not be treated as a Capitalization Adjustment.

(g)        “Cause” will have the meaning ascribed to such term in any written agreement between the Participant and the Company defining such term and, in the absence of such agreement, such term means, with respect to a Participant, the occurrence of any of the following events: (i) such Participant’s willful misconduct, gross negligence, theft, fraud, or other illegal or dishonest conduct, any of which are considered to be materially harmful to the Company; (ii) such Participant’s refusal, unwillingness, failure, or inability to perform material job duties or habitual absenteeism; or (iii) such Participant’s violation of fiduciary duty, violation of any duty of loyalty, or material breach of any material term of any contract between the Participant and the Company. The determination that a termination of the Participant’s Continuous Service is either for Cause or without Cause will be made by the Company, in its sole discretion. Any

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determination by the Company that the Continuous Service of a Participant was terminated with or without Cause for the purposes of outstanding Awards held by such Participant will have no effect upon any determination of the rights or obligations of the Company or such Participant for any other purpose.

(h)        “Change in Control” means the occurrence, in a single transaction or in a series of related transactions, of any one or more of the following events:

(i)        any Exchange Act Person becomes the Owner, directly or indirectly, of securities of the Company representing more than fifty percent (50%) of the combined voting power of the Company’s then outstanding securities other than by virtue of a merger, consolidation or similar transaction. Notwithstanding the foregoing, a Change in Control will not be deemed to occur (A) on account of the acquisition of securities of the Company directly from the Company, (B) on account of the acquisition of securities of the Company by an investor, any affiliate thereof or any other Exchange Act Person that acquires the Company’s securities in a transaction or series of related transactions the primary purpose of which is to obtain financing for the Company through the issuance of equity securities, or (C) solely because the level of Ownership held by any Exchange Act Person (the “Subject Person”) exceeds the designated percentage threshold of the outstanding voting securities as a result of a repurchase or other acquisition of voting securities by the Company reducing the number of shares outstanding, provided that if a Change in Control would occur (but for the operation of this sentence) as a result of the acquisition of voting securities bycombination, following the Company, and after such share acquisition, the Subject Person becomes the Owner of any additional voting securities that, assuming the repurchase or other acquisition had not occurred, increases the percentage of the then outstanding voting securities Owned by the Subject Person over the designated percentage threshold, then a Change in Control will be deemed to occur;

(ii)        there is consummated a merger, consolidation or similar transaction involving (directly or indirectly) the Company and, immediately after the consummation of such merger, consolidation or similar transaction, the stockholders of the Company immediately prior thereto do not Own, directly or indirectly, either (A) outstanding voting securities representing more than fifty percent (50%) of the combined outstanding voting power of the surviving Entity in such merger, consolidation or similar transaction or (B) more than fifty percent (50%) of the combined outstanding voting power of the parent of the surviving Entity in such merger, consolidation or similar transaction, in each case in substantially the same proportions as their Ownership of the outstanding voting securities of the Company immediately prior to such transaction;

(iii)        there is consummated a sale, lease, exclusive license or other disposition ofEffective Time (after taking into account all or substantially all of the consolidated assets of the Company and its Subsidiaries, other than a sale, lease, license or other disposition of all or substantially all of the consolidated assets of the Company and its Subsidiaries to an Entity, more than fifty percent (50%) of the combined voting power of the voting securities of which are Owned by stockholders of the Company in substantially the same proportions as their Ownership of the outstanding voting securities of the Company immediately prior to such sale, lease, license or other disposition; or

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(iv)        individuals who, on the date the Plan is adopted by the Board, are members of the Board (the “Incumbent Board”) cease for any reason to constitute at least a majority of the members of the Board;provided, however, that if the appointment or election (or nomination for election) of any new Board member was approved or recommended by a majority vote of the members of the Incumbent Board then still in office, such new member will, for purposes of this Plan, be considered as a member of the Incumbent Board.

Notwithstanding the foregoing definition or any other provision of the Plan, the term Change in Control will not include a sale of assets, merger or other transaction effected exclusively for the purpose of changing the domicile of the Company and the definition of Change in Control (or any analogous term) in an individual written agreement between the Company or any Affiliate and the Participant will supersede the foregoing definition with respect to Awards subject to such agreement;provided, however, that if no definition of Change in Control or any analogous term is set forth in such an individual written agreement, the foregoing definition will apply.

(i)        “Code” means the Internal Revenue Code of 1986, as amended, including any applicable regulations and guidance thereunder.

(j)        “Committee” means a committee of one or more Directors to whom authority has been delegated by the Board in accordance with Section 2(c).

(k)       “Common Stock” means the common stock of the Company, having one vote per share.

(l)        “Company” means ARCA biopharma, Inc., a Delaware corporation.

(m)     “Consultant” means any person, including an advisor, who is (i) engaged by the Company or an Affiliate to render consulting or advisory services and is compensated for such services, or (ii) serving as a member of the board of directors of an Affiliate and is compensated for such services. However, service solely as a Director, or payment of a fee for such service, will not cause a Director to be considered a “Consultant” for purposes of the Plan. Notwithstanding the foregoing, a person is treated as a Consultant under this Plan only if a Form S-8 Registration Statement under the Securities Act is available to register either the offer or the sale of the Company’s securities to such person.

(n)       “Continuous Service” means that the Participant’s service with the Company or an Affiliate, whether as an Employee, Director or Consultant, is not interrupted or terminated. A change in the capacity in which the Participant renders service to the Company or an Affiliate as an Employee, Consultant or Director or a change in the entity for which the Participant renders such service, provided that there is no interruption or termination of the Participant’s service with the Company or an Affiliate, will not terminate a Participant’s Continuous Service ;provided, however, that if the Entity for which a Participant is rendering services ceases to qualify as an Affiliate, as determined by the Board, in its sole discretion, such Participant’s Continuous Service will be considered to have terminated on the date such Entity ceases to qualify as an Affiliate. To the extent permitted by law, the Board or the chief executive officer of the Company, in that party’s sole discretion, may determine whether Continuous Service will

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be considered interrupted in the case of (i) any leave of absence approved by the Board or chief executive officer, including sick leave, military leave or any other personal leave, or (ii) transfers between the Company, an Affiliate, or their successors. Notwithstanding the foregoing, a leave of absence will be treated as Continuous Service for purposes of vesting in an Award only to such extent as may be provided in the Company’s leave of absence policy, in the written terms of any leave of absence agreement or policy applicable to the Participant, or as otherwise required by law.

(o)        “Corporate Transaction” means the consummation, in a single transaction or in a series of related transactions, of any one or more of the following events:

(i)        a sale or other disposition of all or substantially all, as determined by the Board, in its sole discretion, of the consolidated assets of the Company and its Subsidiaries;

(ii)        a sale or other disposition of at least ninety percent (90%) of the outstanding securities of the Company;

(iii)        a merger, consolidation or similar transaction following which the Company is not the surviving corporation; or

(iv)        a merger, consolidation or similar transaction following which the Company is the surviving corporation but thefractional shares of Common Stock outstanding immediately precedingotherwise issuable to such holder), shall be entitled to receive a cash payment equal to the merger, consolidation or similar transaction are converted or exchanged by virtue of the merger, consolidation or similar transaction into other property, whether in the form of securities, cash or otherwise.

(p)        “Covered Employee” will have the meaning provided in Section 162(m)(3) of the Code.

(q)        “Director” means a member of the Board.

(r)        “Disability” means, with respectfraction to a Participant, the inability ofwhich such Participant to engage in any substantial gainful activity by reason of any medically determinable physical or mental impairment that canholder would otherwise be expected to result in death or that has lasted or can be expected to last for a continuous period of not less than twelve (12) months, as provided in Sections 22(e)(3) and 409A(a)(2)(c)(i) of the Code, and will be determinedentitled multiplied by the Board on the basis of such medical evidence as the Board deems warranted under the circumstances.

(s)        Dissolution”means when the Company, after having executed a certificate of dissolution with the State of Delaware, has completely wound up its affairs. Conversion of the Company into a Limited Liability Company will not be considered a “Dissolution” for purposes of the Plan.

(t)        “Effective Date” means the effective date of this amended and restated Plan document, which is the date of the annual meeting of stockholders of the Company held in calendar year 2016, provided the Plan is approved by the Company’s stockholders at such meeting.

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(u)        “Employee” means any person employed by the Company or an Affiliate. However, service solely as a Director, or payment of a fee for such services, will not cause a Director to be considered an “Employee” for purposes of the Plan.

(v)        “Entity” means a corporation, partnership, limited liability company or other entity.

(w)        “Exchange Act” means the Securities Exchange Act of 1934, as amended, and the rules and regulations promulgated thereunder.

(x)        “Exchange Act Person” means any natural person, Entity or “group” (within the meaning of Section 13(d) or 14(d) of the Exchange Act), except that “Exchange Act Person” will not include (i) the Company or any Subsidiary of the Company, (ii) any employee benefit plan of the Company or any Subsidiary of the Company or any trustee or other fiduciary holding securities under an employee benefit plan of the Company or any Subsidiary of the Company, (iii) an underwriter temporarily holding securities pursuant to a registered public offering of such securities, (iv) an Entity Owned, directly or indirectly, by the stockholders of the Company in substantially the same proportions as their Ownership of stock of the Company; or (v) any natural person, Entity or “group” (within the meaning of Section 13(d) or 14(d) of the Exchange Act) that, as of the Effective Date, is the Owner, directly or indirectly, of securities of the Company representing more than 50% of the combined voting power of the Company’s then outstanding securities.

(y)        “Fair Market Value” means, as of any date, thefair value of the Common Stock determined as follows:

(i)        If the Common Stock is listed on any established stock exchange or traded on any established market, the Fair Market Value of a share of Common Stock will be, unless otherwise determined by the Board,the closing sales price for such stock as quoted on such exchange or market (or the exchange or market with the greatest volume of trading in the Common Stock)on the date of determination, as reported in a source the Board deems reliable.

(ii)        Unless otherwise provided by the Board, if there is no closing sales price for the Common Stock on the date of determination, then the Fair Market Value will be the closing selling price on the last preceding date for which such quotation exists.

(iii)        In the absence of such markets for the Common Stock, the Fair Market Value will be determined by the Board in good faith and in a manner that complies with Sections 409A and 422 of the Code.

(z)        “Incentive Stock Option” means an option granted pursuant to Section 5 of the Plan that is intended to be, and qualifies as, an “incentive stock option” within the meaning of Section 422 of the Code.

(aa)        “Non-Employee Director” means a Director who either (i) is not a current employee or officer of the Company or an Affiliate, does not receive compensation, either directly or indirectly, from the Company or an Affiliate for services rendered as a consultant or in any capacity other than as a Director (except for an amount as to which disclosure would not

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be required under Item 404(a) of Regulation S-K promulgated pursuant to the Securities Act (“Regulation S-K”)), does not possess an interest in any other transaction for which disclosure would be required under Item 404(a) of Regulation S-K, and is not engaged in a business relationship for which disclosure would be required pursuant to Item 404(b) of Regulation S-K; or (ii) is otherwise considered a “non-employee director” for purposes of Rule 16b-3.

(bb)        “Nonstatutory Stock Option” means any option granted pursuant to Section 5 of the Plan that does not qualify as an Incentive Stock Option.

(cc)        “Officer” means a person who is an officer of the Company within the meaning of Section 16 of the Exchange Act.

(dd)        “Option” means an Incentive Stock Option or a Nonstatutory Stock Option to purchase shares of Common Stock granted pursuant to the Plan.

(ee)        “Option Agreement” means a written agreement between the Company and an Optionholder evidencing the terms and conditions of an Option grant. Each Option Agreement will be subject to the terms and conditions of the Plan.

(ff)        “Optionholder” means a person to whom an Option is granted pursuant to the Plan or, if applicable, such other person who holds an outstanding Option.

(gg)        “Other Stock Award” means an award based in whole or in part by reference to the Common Stock which is granted pursuant to the terms and conditions of Section 6(d).

(hh)        “Other Stock Award Agreement” means a written agreement between the Company and a holder of an Other Stock Award evidencing the terms and conditions of an Other Stock Award grant. Each Other Stock Award Agreement will be subject to the terms and conditions of the Plan.

(ii)        “Outside Director” means a Director who either (i) is not a current employee of the Company or an “affiliated corporation” (within the meaning of Treasury Regulations promulgated under Section 162(m) of the Code), is not a former employee of the Company or an “affiliated corporation” who receives compensation for prior services (other than benefits under a tax-qualified retirement plan) during the taxable year, has not been an officer of the Company or an “affiliated corporation,” and does not receive remuneration from the Company or an “affiliated corporation,” either directly or indirectly, in any capacity other than as a Director, or (ii) is otherwise considered an “outside director” for purposes of Section 162(m) of the Code.

(jj)        “Own,” “Owned,” “Owner,” “Ownership” means a person or Entity will be deemed to “Own,” to have “Owned,” to be the “Owner” of, or to have acquired “Ownership” of securities if such person or Entity, directly or indirectly, through any contract, arrangement, understanding, relationship or otherwise, has or shares voting power, which includes the power to vote or to direct the voting, with respect to such securities.

(kk)        “Participant” means a person to whom an Award is granted pursuant to the Plan or, if applicable, such other person who holds an outstanding Stock Award.

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(ll)        “Performance Cash Award” means an award of cash granted pursuant to the terms and conditions of Section 6(c)(ii).

(mm)        “Performance Criteria” means the one or more criteria that the Board or Committee will select for purposes of establishing the Performance Goals for a Performance Period. The Performance Criteria that will be used to establish such Performance Goals may be based on any one of, or combination of, the followingEffective Time, as determined by the Board or Committee: (i) revenue; (ii) gross margin; (iii) operating margin; (iv) operating income; (v) pre-tax profit; (vi) earnings before interest, taxes and depreciation; (vii) net income; (viii) cash flow; (ix) expenses; (x) the market price of the Stock; (xi) earnings per share; (xii) return on stockholder equity; (xiii) return on capital; (xiv) return on net assets; (xv) economic value added; (xvi) number of customers; (xvii) market share; (xviii) return on investment; (xix) profit after tax; (xx) clinical trial milestones; (xxi) regulatory product approval milestones; (xxii) strategic partnership milestones; (xxiii) customer satisfaction; and,Directors.

Each stock certificate that, immediately prior to the extent that an Award is not intended to comply with Section 162(m) of the Code, other measures of performance selected by the Board or Committee.

(nn)        “Performance Goals” means, for a Performance Period, the one or more goals established by the Board or Committee for the Performance Period based upon the Performance Criteria. Performance Goals may be based on a Company-wide basis, with respect to one or more business units, divisions, Affiliates, or business segments, and in either absolute terms or relative to the performance of one or more comparable companies or the performance of one or more relevant indices. Unless specified otherwise by the Board or Committee (i) in the Award Agreement at the time the Award is granted or (ii) in such other document setting forth the Performance Goals at the time the Performance Goals are established, the Board or Committee will appropriately make adjustments in the method of calculating the attainment of Performance Goals for a Performance Period as follows: (1) to exclude restructuring and/or other nonrecurring charges; (2) to exclude exchange rate effects; (3) to exclude the effects of changes to generally accepted accounting principles; (4) to exclude the effects of any statutory adjustments to corporate tax rates; (5) to exclude the effects of any unusual or infrequently occurring items as determined under generally accepted accounting principles; (6) to exclude the dilutive effects of acquisitions or joint ventures; (7) to assume that any business divested by the Company achieved performance objectives at targeted levels during the balance of a Performance Period following such divestiture; (8) to exclude the effect of any change in the outstanding shares of common stock of the Company by reason of any stock dividend or split, stock repurchase, reorganization, recapitalization, merger, consolidation, spin-off, combination or exchange of shares or other similar corporate change, or any distributions to common stockholders other than regular cash dividends; (9) to exclude the effects of stock based compensation and the award of bonuses under the Company’s bonus plans; (10) to exclude costs incurred in connection with potential acquisitions or divestitures that are required to be expensed under generally accepted accounting principles; (11) to exclude the goodwill and intangible asset impairment charges that are required to be recorded under generally accepted accounting principles and (12) to exclude the effect of any other unusual, non-recurring gain or loss or other extraordinary item. In addition, the Board or Committee retains the discretion to reduce or eliminate the compensation or economic benefit due upon attainment of Performance Goals and to define the manner of calculating the Performance Criteria it selects to use for such Performance Period. Partial achievement of the specified criteria may result in the payment or vesting corresponding to the degree of

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achievement as specified in the Stock Award Agreement or the written terms of a Performance Cash Award.

(oo)        “Performance Period” means the period of time selected by the Board or Committee over which the attainment of one or more Performance Goals will be measured for the purpose of determining a Participant’s right to and the payment of a Stock Award or a Performance Cash Award. Performance Periods may be of varying and overlapping duration, at the sole discretion of the Board.

(pp)        “Performance Stock Award” means a Stock Award granted under the terms and conditions of Section 6(c)(i).

(qq)        “Plan” means this ARCA biopharma, Inc. 2013 Equity Incentive Plan.

(rr)        “Restricted Stock Award” means an award ofEffective Time, represented shares of Common Stock which is granted pursuantthat were issued and outstanding immediately prior to the termsEffective Time shall, from and conditionsafter the Effective Time, automatically and without the necessity of Section 6(a).

(ss)        “Restricted Stock Award Agreement” means a written agreement betweenpresenting the Company and a holdersame for exchange, represent that number of a Restricted Stock Award evidencing the terms and conditions of a Restricted Stock Award grant. Each Restricted Stock Award Agreement will be subject to the terms and conditions of the Plan.

(tt)        “Restricted Stock Unit Award” means a right to receivewhole shares of Common Stock after the Effective Time into which is granted pursuant to the terms and conditionsshares of Section 6(b).

(uu)        “RestrictedCommon Stock Unit Award Agreement” means a written agreement betweenformerly represented by such certificate shall have been combined (as well as the Company and a holder of a Restricted Stock Unit Award evidencing the terms and conditions of a Restricted Stock Unit Award grant. Each Restricted Stock Unit Award Agreement will be subject to the terms and conditions of the Plan.

(vv)        “Rule 16b-3” means Rule 16b-3 promulgated under the Exchange Act or any successor to Rule 16b-3, as in effect from time to time.

(ww)        “Securities Act” means the Securities Act of 1933, as amended.

(xx)        “Stock Appreciation Right” or “SAR” means a right to receive cash in lieu of fractional shares of Common Stock after the appreciation onEffective Time), provided however, that each person of record holding a certificate that represented shares of Common Stock that is grantedwere issued and outstanding immediately prior to the Effective Time shall receive, upon surrender of such certificate, a new certificate evidencing and representing the number of whole shares of Common Stock after the Effective Time into which the shares of Common Stock formerly represented by such certificate shall have been combined.”

FOURTH:           Thereafter, pursuant to a resolution by the terms and conditionsBoard, this Certificate of Amendment was submitted to the stockholders of the Corporation for their approval in accordance with the provisions of Section 5.

(yy)        “Stock Appreciation Right Agreement” means a written agreement between the Company211 and a holder of a Stock Appreciation Right evidencing the terms and conditions of a Stock Appreciation Right grant. Each Stock Appreciation Right Agreement will be subject to the terms and conditions242 of the Plan.

(zz)        “Stock Award” means any right to receive Common Stock granted under the Plan, including an Incentive Stock Option, a Nonstatutory Stock Option, a Restricted Stock Award, a Restricted Stock Unit Award, a Stock Appreciation Right, a Performance Stock Award or any Other Stock Award.

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(aaa)    “Stock Award Agreement” means a written agreement between the Company and a Participant evidencing the terms and conditions of a Stock Award grant. Each Stock Award Agreement will be subject to the terms and conditionsDGCL. Accordingly, said proposed amendment has been adopted in accordance with Section 242 of the Plan.DGCL.

(bbb)    IN WITNESS WHEREOF“,SubsidiaryARCABIOPHARMA, INC.” means, with respect has caused this Certificate of Amendment to the Company, (i) any corporationbe signed by its duly authorized officer this ______ day of which more than 50% of the outstanding capital stock having ordinary voting power to elect a majority of the board of directors of such corporation (irrespective of whether, at the time, stock of any other class or classes of such corporation will have or might have voting power by reason of the happening of any contingency) is at the time, directly or indirectly, Owned by the Company, and (ii) any partnership, limited liability company or other entity in which the Company has a direct or indirect interest (whether in the form of voting or participation in profits or capital contribution) of more than 50%.________, 2018.

(ccc)    “Ten Percent Stockholder” means a person who Owns (or is deemed to Own pursuant to Section 424(d) of the Code) stock possessing more than ten percent of the total combined voting power of all classes of stock of the Company or any Affiliate.

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