UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of
the Securities Exchange Act of 1934 (Amendment No.          )

CELLDEX THERAPEUTICS, INC.
Perryville III Building
53 Frontage Road, Suite 220
Hampton, NJ 08827

NOTICE OF ANNUAL MEETING OF STOCKHOLDERS

To be held on June 19, 201918, 2020

To the Stockholders of
Celldex Therapeutics, Inc.

        NOTICE IS HEREBY GIVEN that the Annual Meeting of Stockholders of Celldex Therapeutics, Inc. (the "Company" or "we" or "us") will be held on June 18, 2020 beginning at 9:00 a.m. Eastern Time. In light of the coronavirus/COVID-19 outbreak and governmental decrees that in-person gatherings be postponed or canceled, and in the best interests of public health and the health and safety of our stockholders, employees and Board of Directors, we are planning to hold the Annual Meeting virtually via the Internet at www.virtualshareholdermeeting.com/CLDX2020. Unless we publicly announce a change in our plans in the manner described in the attached proxy statement, you will not be able to attend the Annual Meeting in person. If we elect to hold a physical meeting, it will be held at the offices of Lowenstein Sandler LLP, One Lowenstein Drive Roseland, NJ 07068, on June 19, 2019 beginning at 9:00 a.m. local time.07068. At the meeting, stockholders will act on the following matters to:

•

elect six directors to serve until the next Annual Meeting of Stockholders and until their respective successors shall have been duly elected and qualified;



•

ratify the appointment of PricewaterhouseCoopers LLP as our independent registered public accounting firm for the year ending December 31, 2019;2020;



•

approve an amendment to our 2008 Stock Option and Incentive Plan including an increase in the number of the shares reserved for issuance thereunder by 900,0001,900,000 shares to 2,233,3334,133,333 shares and certain other administrative changes;



•

approve an amendment to our 2004 Employee Stock Purchase Plan to increase the shares reserved for issuance thereunder by 250,000 shares to 276,666 shares;



•

approve, on an advisory basis, the compensation of the Company's Named Executive Officers as disclosed in this proxy statement; and



•

address any other matters that may properly come before the meeting.

        Only stockholders of record at the close of business on April 22, 201921, 2020 are entitled to receive notice of and to vote at the Annual Meeting or any postponement or adjournment thereof.

        Your vote is important. Whether you plan to attend the meeting or not, you may vote your shares by marking, signing, dating and mailing the enclosed proxy card in the envelope provided. If you attend the meeting and prefer to vote in person, you may do so even if you have already voted your shares. You may revoke your proxy in the manner described in the proxy statement at any time before it has been voted at the meeting.

May 2, 20194, 2020
Hampton, NJ

CELLDEX THERAPEUTICS, INC.
Perryville III Building
53 Frontage Road, Suite 220
Hampton, NJ 08827

PROXY STATEMENT

        This proxy statement contains information related to the Annual Meeting of Stockholders to be held on June 19, 201918, 2020 at 9:00 a.m. local time,Eastern Time. In light of the coronavirus/COVID-19 outbreak and governmental decrees that in-person gatherings be postponed or canceled, and in the best interests of public health and the health and safety of our stockholders, employees and Board of Directors, we are planning to hold the Annual Meeting virtually via the Internet. Unless we publicly announce a change in our plans, in order to attend our Annual Meeting, you must log in to www.virtualshareholdermeeting.com/CLDX2020 using the 16-digit control number on the notice, proxy card or voting instruction form that accompanied the proxy materials.

        Our Annual Meeting could be adjourned or postponed to another date and/or time. If the pandemic abates to the extent that the Company believes that it will be safe for all constituencies to attend in person, we may also determine to revert to our original plans to hold the Annual Meeting in person. If we make any such determination, we will announce plans for an in-person meeting in a press release that we will disseminate and file with the SEC and on the investor relations page of our website at www.celldex.com. In such event, our meeting would be held at the offices of Lowenstein Sandler LLP, One Lowenstein Drive, Roseland, NJ 07068 or at such other time and place to which the Annual Meeting may be adjourned or postponed. At this point, however, we expect to hold the Annual Meeting virtually via the Internet. A list of record holders of the Company's common stock entitled to vote at the Annual Meeting will be available for examination by any stockholder, for any purpose germane to the Annual Meeting, at our principal offices at Perryville III Building, 53 Frontage Road, Suite 220, Hampton, New Jersey 08827, during normal business hours for ten days prior to the Annual Meeting. A list will also be available on the virtual meeting platform during the Annual Meeting.

        The enclosed proxy is solicited by the Board of Directors of Celldex Therapeutics, Inc. The proxy materials relating to the Annual Meeting are being mailed to stockholders entitled to vote at the meeting on or about May 2, 2019.4, 2020.

        Important Notice of Availability of Proxy Materials for the Annual Meeting of Stockholders to be held on June 19, 2019.18, 2020.

        Our proxy materials, including our Proxy Statement for the 20192020 Annual Meeting, 20182019 Annual Report to Stockholders (which contains our Annual Report on Form 10-K) and proxy card, are available on the Internet at www.proxyvote.com.

ABOUT THE MEETING

Why are we calling this Annual Meeting?

        We are calling the Annual Meeting to seek the approval of our stockholders to:

•

elect six directors to serve until the next Annual Meeting of Stockholders and until their respective successors shall have been duly elected and qualified;



•

ratify the appointment of PricewaterhouseCoopers LLP as our independent registered public accounting firm for the year ending December 31, 2019;2020;

•

approve an amendment to our 2008 Stock Option and Incentive Plan including an increase in the number of the shares reserved for issuance thereunder by 900,0001,900,000 shares to 2,233,3334,133,333 shares and other administrative changes;



•

approve an amendment to our 2004 Employee Stock Purchase Plan to increase the shares reserved for issuance thereunder by 250,000 shares to 276,666 shares;



•

approve, on an advisory basis, the compensation of the Company's Named Executive Officers as disclosed in this proxy statement; and



•

address any other matters that may properly come before the meeting.

What are the Board's recommendations?

        Our Board of Directors recommends that you vote:

•

FOR the election of each of the six director nominees;



•

FOR the ratification of the appointment of PricewaterhouseCoopers LLP as our independent registered public accounting firm for the year ending December 31, 2019;2020;

•

FOR the approval of an amendment to our 2008 Stock Option and Incentive Plan including an increase in the number of the shares reserved for issuance thereunder by 900,0001,900,000 shares to 2,233,3334,133,333 shares and certain other administrative changes;



•

FOR the approval of an amendment to our 2004 Employee Stock Purchase Plan to increase the shares reserved for issuance thereunder by 250,000 shares to 276,666 shares; and



•

FOR an advisory vote on the compensation of the Named Executive Officers as described in this proxy statement.

Who is entitled to vote at the meeting?

        Only stockholders of record at the close of business on the record date, April 22, 2019,21, 2020, are entitled to receive notice of the Annual Meeting and to vote the shares of common stock that they held on that date at the meeting, or any postponement or adjournment of the meeting. Holders of our common stock are entitled to one vote per share on each matter to be voted upon. As of the record date, we had 13,534,57918,082,050 outstanding shares of common stock.

Who can attend the meeting?

        All stockholders as of the record date, or their duly appointed proxies, may attend the Annual Meeting. If, as we expect, the Annual Meeting is held virtually, attendance shall solely be via the Internet at www.virtualshareholdermeeting.com/CLDX2020 using the 16-digit control number on the notice, proxy card or voting instruction form that accompanied the proxy materials. In that event, stockholders will not be able to attend the Annual Meeting in person.

        The live webcast of the Annual Meeting will begin promptly at 9:00 am Eastern Time. Online access to the audio webcast will open approximately 10 minutes prior to the start of the Annual Meeting to allow time for our stockholders to log in and test their devices' audio system. We encourage our stockholders to access the meeting in advance of the designated start time.

        Stockholders may also vote, and submit written questions, during the Annual Meeting on www.virtualshareholdermeeting.com/CLDX2020. To demonstrate proof of stock ownership, you will need to enter the 16-digit control number received with your notice, proxy card or voting instruction form to submit questions and vote at our Annual Meeting. If you hold your shares in "street name" (that is, through a broker or other nominee), you will need authorization from your broker or nominee in order to vote. We intend to answer questions submitted during the meeting that are pertinent to the Company and the items being brought for stockholder vote at the Annual Meeting, as time permits, and in accordance with the Rules of Conduct for the Annual Meeting. To promote fairness, efficiently use the Company's resources and ensure all stockholder questions are able to be addressed, we will respond to no more than one question from a single stockholder. Questions and answers will be

grouped by topic and substantially similar questions will be grouped and answered once. We have retained Broadridge Financial Solutions to host our virtual annual meeting and to distribute, receive, count and tabulate proxies.

        The following instructions apply in the event that we announce that we have changed our plans and intend to hold the meeting in person at the offices of Lowenstein Sandler LLP in Roseland, New Jersey: Please note that if you hold your shares in "street name" (that is, through a broker or other nominee), you will need to bring a copy of your proxy card delivered to you by your broker or a legal proxy given to you by your broker and check in at the registration desk at the meeting. For security reasons, you must comply with our pre-registration requirements, you must present a form of government issued photograph identification on the day of the Annual Meeting, and you must arrive at least thirty minutes prior to the meeting in order to attend the Annual Meeting. If you are a stockholder of record and plan to attend the Annual Meeting, please contact Kathy Reamer by email at kreamer@celldex.com or by phone at 908-200-7500 ext. 7508 to register to attend the Annual Meeting. If you hold shares through an intermediary, such as a bank or broker, and you plan to attend, you must send a written request to attend either by regular mail or email, along with proof of share ownership, such as a bank or brokerage firm account statement, confirming ownership to: Celldex Therapeutics, Inc., Perryville III Building, 53 Frontage Road, Suite 220, Hampton, NJ 08827, Attn: Kathy Reamer or kreamer@celldex.com. Attendance at the Annual Meeting will be limited to persons who pre-registered on or before June 13, 2019,12, 2020, who present a form of government-issued photograph identification on the day of the Annual Meeting and who arrive by 8:30 a.m. local time. The Rules of Conduct for the Annual Meeting would also apply, to the extent relevant, at an in-person meeting.

What constitutes a quorum?

        The presence at the Annual Meeting, in person or by proxy, of the holders of a majority of our common stock outstanding on the record date will constitute a quorum for our meeting. Signed proxies received but not voted and broker non-votes will be included in the calculation of the number of shares considered to be present at the meeting.

How do I vote?

        You can vote on matters that come before the Annual Meeting by completing, dating and signing the enclosed proxy card and returning it in the enclosed postage-paid envelope.

        Your shares will be voted as you indicate on your proxy card. If you vote the enclosed proxy but you do not indicate your voting preferences, and with respect to any other matter that properly comes before the meeting, the individuals named on the proxy card will vote your shares FOR the matters submitted at the meeting, or if no recommendation is given, in their own discretion.

        If you are a stockholder of record, to submit your proxy by telephone or via the Internet, follow the instructions on the proxy card. If you hold your shares in street name, you may vote by telephone or via the Internet as instructed by your broker, bank or other nominee.

        You will have the right to vote at the Annual Meeting.

        If, as we expect, we hold the Annual Meeting remotely via the Internet, you will have the right to vote on the day of, or during, the Annual Meeting on www.virtualshareholdermeeting.com/CLDX2020. To demonstrate proof of stock ownership, you will need to enter the 16-digit control number received with your notice, proxy card or voting instruction form to vote at our Annual Meeting if it is held remotely.

        If we change our plans, hold the meeting in person and you attend the Annual Meeting, you may vote in person. However, if your shares are held in the name of a bank, broker or other nominee, you must obtain a legal proxy, executed in your favor, from the holder of record to be able to vote in

person at the Annual Meeting. In that case, you should allow yourself enough time prior to the Annual Meeting to obtain this proxy from the holder of record. If you attend the Annual Meeting and prefer to vote in person, you may do so even if you have already voted your shares by proxy. Even if you plan to attend our Annual Meeting, we recommend that you also submit your proxy as described above so that your vote will be counted if you later decide not to attend our Annual Meeting.

What if I vote and then change my mind?

        You may revoke your proxy at any time before it is exercised by:

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filing with the Secretary of the Company a notice of revocation;



•

sending in another duly executed proxy bearing a later date; or



•

attending the meeting and casting your vote in person.

        Your latest vote will be the vote that is counted.

What is the difference between holding shares as a stockholder of record and as a beneficial owner?

        Many of our stockholders hold their shares through a stockbroker, bank or other nominee rather than directly in their own name. As summarized below, there are some distinctions between shares held of record and those owned beneficially.

Stockholder of Record

        If your shares are registered directly in your name with our transfer agent, Computershare Trust Company, N.A., you are considered, with respect to those shares, the stockholder of record. As the stockholder of record, you have the right to grant your voting proxy directly to us or to vote in person at the Annual Meeting.

Beneficial Owner

        If your shares are held in a stock brokerage account or by a bank or other nominee, you are considered the beneficial owner of shares held in street name, and these proxy materials are being forwarded to you by your broker, bank or nominee which is considered, with respect to those shares, the stockholder of record. As the beneficial owner, you have the right to direct your broker as to how to vote and are also invited to attend the Annual Meeting. However, because you are not the stockholder of record, you may not vote these shares in person at the Annual Meeting unless you obtain a signed proxy from the record holder giving you the right to vote the shares. If you do not vote your shares or otherwise provide the stockholder of record with voting instructions, your shares may constitute broker non-votes. The effect of broker non-votes is more specifically described in "What vote is required to approve each proposal?" below.

What are "broker non-votes"?

        Banks and brokers acting as nominees are permitted to use discretionary voting authority to vote proxies for proposals that are deemed "routine" by the New York Stock Exchange, but are not permitted to use discretionary voting authority to vote proxies for proposals that are deemed "non-routine" by the New York Stock Exchange. The determination of which proposals are deemed "routine" versus "non-routine" may not be made by the New York Stock Exchange until after the date on which this proxy statement has been mailed to you. As such, it is important that you provide voting instructions to your bank, broker or other nominee, if you wish to determine the voting of your shares. If the New York Stock Exchange determines a proposal to be "non-routine," failure to vote, or to

instruct your broker how to vote any shares held for you in your broker's names will have the same effect as a vote against such proposal.

        A broker "non-vote" occurs when a proposal is deemed "non-routine" and a nominee holding shares for a beneficial owner does not have discretionary voting authority with respect to the matter being considered and has not received instructions from the beneficial owner.

        The election of directors (Proposal No. 1), the approval of an amendment to our 2008 Stock Option and Incentive Plan including an increase in the number of the shares reserved for issuance thereunder by 900,0001,900,000 shares to 2,233,333 shares and certain other administrative changes (Proposal No. 3), the approval of an amendment to our 2004 Employee Stock Purchase Plan to increase the shares reserved for issuance thereunder by 250,000 shares to 276,666 shares4,133,333 shares (Proposal No. 4),3) and the advisory vote on the compensation of our Named Executive Officers (Proposal No. 5)4) are generally not considered to be "routine" matters, and brokers are not permitted to vote on those matters if the broker has not received instructions from the beneficial owner. Accordingly, it is particularly important that beneficial owners instruct their brokers how they wish to vote their shares. The ratification of our independent registered public accounting firm (Proposal No. 2) is generally considered to be a "routine" matter, and hence your brokerage firm will be able to vote on Proposal No. 2 even if it does not receive instructions from you, so long as it holds your shares in its name.

What vote is required to approve each proposal?

        Holders of a majority of the outstanding shares entitled to vote must be present, in person or by proxy, at the Annual Meeting in order to have the required quorum for the transaction of business. Pursuant to Delaware corporate law, abstentions and broker non-votes will be counted for the purpose of determining whether a quorum is present. Abstentions and broker non-votes are not counted for the purpose of determining the number of votes cast and will therefore not have any effect with respect to any of the proposals.

        Assuming that a quorum is present, the following votes will be required:

•

With respect to the election of directors (Proposal No. 1), each nominee presented in Proposal 1 must be elected by a majority of the votes cast in person or by proxy at the Annual Meeting. Nominees are elected by a majority vote for non-contested director elections. Because the number of nominees properly nominated for the Annual Meeting is the same as the number of directors to be elected, the election of directors at this Annual Meeting is non-contested. If the number of votes "For" a nominee exceeds the number of votes "Withheld" (among votes properly cast in person or by proxy), then the nominee will be elected.



•

With respect to the ratification of the appointment of PricewaterhouseCoopers LLP as our independent registered public accounting firm (Proposal No. 2), approval will require the affirmative vote of the holders of a majority of the total votes cast in person or by proxy at the Annual Meeting.



•

With respect to the approval of an amendment to our 2008 Stock Option and Incentive Plan including an increase in the number of the shares reserved for issuance thereunder by 900,0001,900,000 shares to 2,233,3334,133,333 shares and certain other administrative changes; (Proposal No. 3), approval will require the affirmative vote of the holders of a majority of the total votes cast in person or by proxy at the Annual Meeting.



•

With respect to the approval of an amendment to our 2004 Employee Stock Purchase Plan to increase the shares reserved for issuance thereunder by 250,000 shares to 276,666 shares shares (Proposal No. 4), approval will require the affirmative vote of the holders of a majority of the total votes cast in person or by proxy at the Annual Meeting.

•

With respect to the advisory vote on the compensation of our Named Executive Officers as disclosed in this proxy statement (Proposal No. 5)4), approval will require the affirmative vote of the holders of a majority of the total votes cast in person or by proxy at the Annual Meeting.

        Holders of the common stock will not have any dissenters' rights of appraisal in connection with any of the matters to be voted on at the meeting.

How are we soliciting this proxy?

        We are soliciting this proxy on behalf of our Board of Directors by mail and will pay all expenses associated therewith. Some of our officers and other employees also may, but without compensation other than their regular compensation, solicit proxies by further mailing or personal conversations, or by telephone, facsimile or other electronic means. We will also, upon request, reimburse brokers and other persons holding stock in their names, or in the names of nominees, for their reasonable out-of-pocket expenses for forwarding proxy materials to the beneficial owners of the capital stock and to obtain proxies.

PROPOSAL 1: TO ELECT SIX DIRECTORS TO SERVE UNTIL THE NEXT ANNUAL MEETING
AND UNTIL THEIR SUCCESSORS HAVE BEEN DULY
ELECTED AND QUALIFIED

(Proposal No. 1)

        At the Annual Meeting, six directors are to be elected. All directors of the Company hold office until the next Annual Meeting of Stockholders or until their respective successors are duly elected and qualified or their earlier resignation or removal.

        It is the intention of the persons named in the proxies for the holders of common stock to vote the proxies for the election of the nominees named below, unless otherwise specified in any particular proxy. Our management does not contemplate that the nominees will become unavailable for any reason, but if that should occur before the meeting, proxies will be voted for another nominee, or other nominees, to be selected by our Board of Directors. In accordance with our by-laws and Delaware law, a stockholder entitled to vote for the election of directors may withhold authority to vote for certain nominees for directors or may withhold authority to vote for all nominees for directors. Each director nominee must be elected by a majority of the votes cast in person or by proxy at the Annual Meeting. Nominees are elected by a majority vote for non-contested director elections. Because the number of nominees properly nominated for the Annual Meeting is the same as the number of directors to be elected, the election of directors at this Annual Meeting is non-contested. Broker non-votes will not be treated as a vote for or against any particular director nominee and will not affect the outcome of the election. Stockholders may not vote, or submit a proxy, for a greater number of nominees than the six nominees named below.

Nominees for Election

        The persons listed below are our current directors and have been nominated for re-election (the "Director Nominees") to fill the six director positions to be elected by the holders of the common stock. Larry Ellberger is our Chairman of the Board. Mr. Ellberger's term as director will expire at the 2019 Annual Meeting at which time a new Chairman of the Board will be appointed.

        The following biographical descriptions set forth certain information with respect to the Director Nominees, based on information furnished to Celldex by each Director Nominee.

Director Nominees

Karen L. Shoos was appointed Chair of the Board of Directors in June 2019 and has been a director of Celldex since May 2001. Ms. Shoos is currently a consultant in international blood safety and since November 2015, Ms. Shoos has been the Director of Operations for the Maryland Tech Council Venture Mentoring Services Program. From May 2013 to September 2016, Ms. Shoos was Principal Investigator, AABB International Technical Assistance. From October 1994 to May 2013, Ms. Shoos was Chief Executive Officer of AABB. AABB is a professional standards setting and accrediting organization in the fields of blood and cellular therapies. Prior to AABB, from 1984 to 1994, Ms. Shoos held senior positions at the American Red Cross, including Acting Senior Vice

President, Biomedical Services (1993-1994) and Secretary and General Counsel (1990-1993). Prior to the American Red Cross, Ms. Shoos was a lawyer in private practice. Ms. Shoos earned her B.A. from Yale University and her J.D. from Case Western Reserve University.

        Anthony S. Marucci was appointed President and Chief Executive Officer of Celldex in September 2008 and as a director of Celldex in December 2008. Since May 2003, Mr. Marucci has held a number of roles with Celldex, including as a founder, Vice President, Chief Financial Officer, Treasurer and Secretary. In addition, he was Treasurer of Medarex, Inc. (now a part of Bristol-Myers Squibb Co.) from December 1998 to March 2004. Mr. Marucci held a series of senior financial positions at Medarex from December 1998 to May 2003. Mr. Marucci is a member of the Board of Trustees of BioNJ Inc. and also served as its Treasurer through 2010. Mr. Marucci is a member of the Board of the College of

Business and Public Management at Kean University. Mr. Marucci received his M.B.A. from Columbia University and his E.M.H.L.M.H.L. from Brown University.

        Keith L. Brownlie became a director of Celldex in June 2017. Mr. Brownlie was employed by the accounting firm Ernst & Young LLP from 1974 to 2010. At Ernst & Young, he served as audit partner for numerous public companies and was the Life Sciences Industry Leader for the New York Metro Area. Since his retirement from Ernst & Young inFrom 2010 until 2019, Mr. Brownlie has served as a member of the board of directors and chairman of the audit committee of Soligenix, Inc., a publicly held biopharmaceutical company. SinceFrom 2012 until 2019, Mr. Brownlie has served as a member of the board of directors and served as the chairman of the audit committee of Phio Pharmaceuticals Corp. (formerly RXi Pharmaceuticals Corporation), a publicly held biopharmaceutical company. From 2011 to 2013, Mr. Brownlie also served as a member of the board of directors and served as the chairman of the audit committee of EpiCept Corporation, a publicly held biopharmaceutical company. From 2013 to 2014, Mr. Brownlie was a member of the board of directors and served as the chairman of the audit committee of Cancer Genetics, Inc., a publicly held biopharmaceutical company. Mr. Brownlie received a B.S. in Accounting from Lehigh University and is a Certified Public Accountant.

        Herbert J. Conrad became a director of Celldex in March 2008 upon consummation of the AVANT Merger. Mr. Conrad had been a director of Celldex Research since March 2004. Mr. Conrad was President of the U.S. Pharmaceuticals Division of Hoffmann-La Roche, Inc., a pharmaceutical company, from 1982 until his retirement in 1993. Mr. Conrad currently serves as Chairman of the Board of Matinas BioPharma Holdings, Inc., a publicly held biopharmaceutical company. Mr. Conrad serves as an Advisor to the Seaver Autism Center at Mount Sinai Hospital. In addition to serving on the board of directors of privately held biotechnology companies, Mr. Conrad has served as Chairman of the Board of Directors of Pharmasset, Inc., GenVec, Inc. and Bone Care International, Inc. Mr. Conrad has also served as director of Arbutus Biopharma Corporation and was a director and co-founder of Reliant Pharmaceuticals, Inc. He received B.S. and M.S. degrees from the Brooklyn College of Pharmacy and an honorary Doctorate in Humane Letters from Long Island University.

        James J. Marino became a director of Celldex in March 2017. Mr. Marino has served as a member of the board of directors of Onconova Therapeutics, Inc., a publicly held biopharmaceutical company, since July 2015 and is currently a member of their Audit Committee and Chair of their Compensation Committees.Committee. Prior to July 2015, Mr. Marino was a Partner at the global law firm of Dechert LLP for 28 years, where he served as Managing Partner of the Princeton Office. Previously, he served on the board of directors of Pharmacopeia Inc. and has worked in advisory capacities and on the boards of multiple non-profit organizations, including Robert Wood Johnson University Hospital. He currently serves on the Board of Trustees of Wake Forest University and Wake Forest University Baptist Medical Center. Mr. Marino received his B.A., M.B.A., and J.D. from Rutgers University.

Harry H. Penner, Jr. has been a director of Celldex since January 1997 and was Chairman of AVANT prior to the consummation of the AVANT Merger. Mr. Penner has served as Chairman and Chief Executive Officer of Nascent BioScience, LLC, a firm engaged in the creation and development

of new life science companies since 2001. From 1993 to 2001, Mr. Penner was President, Chief Executive Officer and Vice Chairman of Neurogen Corporation. From 1985 to 1993, Mr. Penner was an Executive Vice President of Novo Nordisk A/S, serving from 1988 to 1993 as Executive Vice President for North America and President, Novo Nordisk of North America, and from 1985 to 1988 as the company's Executive Vice President and General Counsel in Denmark. He has served as BioScience Advisor to the Governor and the State of Connecticut, as Co-Chairman of BioCT (formerly Connecticut United for Research Excellence), and as Chairman of the Connecticut Board of Governors of Higher Education and the Connecticut Technology Council. Mr. Penner is currently Chairman of the Board of CaroGen Corporation. Mr. Penner is also Chairman of the Board of Affinimark Technologies, Inc., NeuroCyte Therapeutics, Inc. and QCDx LLC, and a board member of OmaxHealth, Inc., all of which he is a founder. Mr. Penner received a B.A. from the University of

Virginia, a J.D. from Fordham University, and an L.L.M. in International Law from New York University.

Karen L. Shoos has been a director of Celldex since May 2001. Ms. Shoos is currently a consultant in international blood safety and since November 2015, Ms. Shoos has been the Director of Operations for the Maryland Tech Council Venture Mentoring Services Program. From May 2013 to September 2016, Ms. Shoos was Principal Investigator, AABB International Technical Assistance. From October 1994 to May 2013, Ms. Shoos was Chief Executive Officer of AABB. AABB is a professional standards setting and accrediting organization in the fields of blood and cellular therapies. Prior to AABB, from 1984 to 1994, Ms. Shoos held senior positions at the American Red Cross, including Acting Senior Vice President, Biomedical Services (1993-1994) and Secretary and General Counsel (1990-1993). Prior to the American Red Cross, Ms. Shoos was a lawyer in private practice. Ms. Shoos earned her B.A. from Yale University and her J.D. from Case Western Reserve University.

Family Relationships

        There are no family relationships among our Director Nominees, management and other key personnel.

The Board of Directors and Its Committees

Board of Directors

        We are currently managed by a sevensix member Board of Directors, a majority of whom are "independent" as that term is defined in the applicable NASDAQ listing standards. Other than Mr. Marucci, each of our directors is deemed "independent" as that term is defined in the applicable NASDAQ listing standards. Our Board of Directors met sevenfive times in 2018.2019. Each of the directors attended at least 75% of the aggregate of (i) the total number of meetings of our Board of Directors and (ii) the total number of meetings of all committees of our Board of Directors on which the Director served. Our annual meeting of stockholders is generally held to coincide with one of the Board's regularly scheduled meetings. We do not have a formal policy requiring members of the Board of Directors to attend our annual meetings, although our directors typically attend the annual meeting. Each of the then current directors attended the 20182019 Annual Meeting of Stockholders.

Audit Committee

        The Board of Directors has established an Audit Committee currently consisting of Keith L. Brownlie, Chair, Larry EllbergerJames J. Marino and Harry H. Penner, Jr. The Audit Committee makes recommendations concerning the engagement of independent public accountants, reviews with the independent public accountants the scope and results of the audit engagement, approves professional services provided by the independent public accountants, reviews the independence of the independent public accountants, considers the range of audit and non-audit fees, and reviews the adequacy of our internal accounting controls. Each member of the Audit Committee is "independent" as that term is defined in the rules of the SEC and the applicable NASDAQ listing standards. The Board has determined that each Audit Committee member has sufficient knowledge in financial and auditing matters to serve on the Committee. The Board has designated Mr. Brownlie as an "audit committee financial expert," as defined under the applicable rules of the SEC and the applicable NASDAQ listing standards. The Audit Committee met sevenfive times during 2018.2019. Our Board has adopted an Audit Committee Charter, which is available for viewing atwww.celldex.com.

Compensation Committee

        The Board of Directors has established a Compensation Committee currently consisting of James J. Marino, Chair, Herbert J. Conrad and Harry H. Penner, Jr. The primary function of the

1992, holding various positions providing leadership of clinical research and project management prior to completing her tenure there as the Director of Global Study Audit Management. Ms. Crowley received her B.S. in Chemistry with a concentration in Business from Boston College.

Margo Heath-Chiozzi, M.D.    became Senior Vice President, Regulatory Affairs in October 2017. Previously from 2003 until September 2017, Dr. Heath-Chiozzi served in roles of increasing responsibility at Bristol-Myers Squibb Company including Executive Director, Global Regulatory Sciences; Vice President, Global Regulatory Strategy; and Vice President, Global Submissions and Regulatory Policy. Prior to that, from 1995 to 2003, Dr. Heath-Chiozzi served in roles of increasing responsibility at Abbott Laboratories, including Medical Director, Pharmacogenetics; Senior Director, Global Marketed Product Development and Outcomes Research; and Global Project Head, Abbott/Millennium Obesity/Diabetes Alliance. Before joining Abbott, she was appointed to the University of

Hawaii John A. Burns School of Medicine, where she served as Assistant Professor, and was concurrently Director of the HIV Research Clinical at the Queen's Medical Center as well as Director of the Women's Immunology Clinical at the Kapiolani Medical Center for Women and Children, in Honolulu. Dr. Heath-Chiozzi received her B.S. and M.D. from the University of Utah. She received further medical training in internal medicine at Duke University and completed fellowships in infectious disease at Brigham & Women's Hospital and Dana-Farber Cancer Institute in Boston.

        Sam Martin became Senior Vice President, Chief Financial Officer and Secretary in July 2017. Mr. Martin served as Vice President, Finance of Celldex from January 2015 to July 2017 and Senior Director, Finance of Celldex from August 2011 to January 2015. Mr. Martin joined Celldex as the Director of Financial Reporting, Planning and Analysis in 2009. Prior to joining Celldex, from 2000 to 2009, Mr. Martin served in roles of increasing responsibility at Alseres Pharmaceuticals, Inc., most recently serving as the Director of Finance and Corporate Compliance. Mr. Martin began his career at Ernst & Young LLP, holding various positions prior to completing his tenure as Audit Manager. Mr. Martin received an M.B.A. from Boston University, a B.S. from Skidmore College and is a Certified Public Accountant.

        Ronald Pepin, Ph.D. became Senior Vice President and Chief Business Officer of Celldex in July 2011. From June 2010 to April 2011, Dr. Pepin served as Vice President at Shire Pharmaceuticals. From August 2000 to December 2009, Dr. Pepin was Senior Vice President, Business Development at Medarex. Earlier in his career, Dr. Pepin was Executive Director of External Science and Technology at Bristol-Myers Squibb Company. Dr. Pepin received his B.A. from Tufts University and his Ph.D. in Genetics from Georgetown University.

        Richard Wright, Ph.D. became Senior Vice President and Chief Commercial Officer of Celldex in July 2015. Dr. Wright served as Vice President of Commercial Operations of Celldex from April 2012 to July 2015. From November 2010 to April 2012, Dr. Wright was Managing Director of Navigant Consulting, a global life sciences consulting practice. From September 2003 to October 2010, Dr. Wright held several senior leadership roles at Bristol-Myers Squibb including Senior Vice President of the U.S. ImmunoScience Division. Dr. Wright currently serves on the Scientific Advisory Board for the Seaver Foundation, a nonprofit organization supporting the Center for Autism Treatment and Research at Mount Sinai Hospital. Dr. Wright received his B.S. in Biological Sciences from Rutgers University and his M.S. and Ph.D. in Microbiology and Molecular Genetics from The University of Medicine and Dentistry of New Jersey (Rutgers University). He received an M.B.A. in Marketing and Finance from Columbia University.

Diane C. Young, M.D. became Senior Vice President, Chief Medical Officer of Celldex in June 2019. Previously, from July 2015 until February 2019, Dr. Young served as Vice President, Chief Medical Officer of GTx, Inc. Prior to that, from 2002 to June 2015, Dr. Young served in roles of increasing responsibility at Novartis Oncology including Vice President, Head of Oncology Clinical Development and Medical Affairs, Latin America and Canada; Vice President, Global Head of Medical

Affairs, Oncology Business Unit; and Vice President, Global Head of Clinical Development Phase 2/3, Oncology Business Unit. Prior to that, from 1993 to 2002, Dr. Young served in roles of increasing responsibility at R.W. Johnson Pharmaceutical Research Institute including Vice President for Global Development and Senior Director, Clinical Research and Development. She also held roles at Sandoz Research Institute from 1991 to 1993 including Director of Clinical Research, Cytokine Development Unit and Associate Medical Director. From 1988 to 1990, she was Assistant Director, Clinical Investigation II at Hoffman-LaRoche, Inc. She received her A.B. in Biochemical Sciences from Harvard University and her M.D. from Harvard Medical School. She received further medical training in internal medicine at Johns Hopkins Hospital and Vanderbilt University Hospital and completed a fellowship in medical oncology at Dana-Farber Cancer Institute.

EXECUTIVE COMPENSATION

Compensation Discussion and Analysis

Introduction

        Our Compensation Committee oversees and administers our executive compensation programs. The Committee's complete roles and responsibilities are set forth in the written charter of the Compensation Committee adopted by our Board of Directors, which can be found at our website,www.celldex.com.

Overview

        Our executive compensation programs are designed to deliver compensation that is competitive with our peer group and that allows us to attract and retain superior talent who can perform effectively and succeed in a demanding business environment. Our compensation programs are also designed to reward performance against pre-established goals and align the interests of our executives with our stockholders. We believe that the compensation of our executive officers should focus executive behavior on the achievement of near-term corporate targets as well as long-term business objectives and strategies. We believe that pay-for-performance compensation programs, which reward our executives when they achieve individual and/or corporate goals, create stockholder value and thus have emphasized company and individual performance in setting compensation. We use a combination of base salary, annual cash incentive compensation programs, a long-term equity incentive compensation program and a broad-based benefits program to create a competitive compensation package for our executive management team.

        We describe below our compensation philosophy, policies and practices with respect to our (i) Chief Executive Officer, (ii) Chief Financial Officer, and (iii) three most highly compensated executive officers, other than the Chief Executive Officer and Chief Financial Officer, who were serving as executive officers as of December 31, 2018,2019, collectively referred to as our Named Executive Officers. In 2018,2019, our Named Executive Officers were Mr. Marucci, Dr. Keler, Ms. Crowley, Dr. Heath-Chiozzi, and Mr. Martin.

        As a biopharmaceutical company focusing on the development of a pipeline of drug candidates to treat cancer and other difficult-to-treat diseases and several immunotherapy technologies, we establish corporate goals that are designed to contribute to the development of our lead programs, ensure that we manage our cash effectively and have sufficient funding to complete near-term development activities for our lead drug candidates and, where appropriate, to pursue partnerships and collaborations through which we can leverage the value of our drug candidates. We seek to link the financial interests of our Named Executive Officers to those of our stockholders by tying compensation to the achievement of these strategic corporate goals, which we believe will drive long-term stockholder value. Each year we establish corporate goals, the achievement of which we believe are essential to the long-term success of our business.

        The Compensation Committee has adopted a compensation philosophy of targeting our executive compensation to the 50^th percentile of executive compensation of our peer group and the Radford Global Life Sciences Survey results. Executive compensation may be above or below the 50^th percentile based on an executive's experience, scope of position, individual performance and company constraints. The Compensation Committee made no change toincreased the annual base salary for Mr. Marucci, Dr. Keler, Ms. Crowley, and Dr. Heath-Chiozzi and Mr. Martin by 4.0% to 5.5% in mid-2018. The Compensation Committee increased Mr. Martin's annual base salary by 24.6% in July 2018 to bring his compensation closer tomid-2019, depending on the 50^th percentile range.position.

        In December 2018November 2019 and January 2019,2020, our Compensation Committee reviewed our performance relative to our 20182019 corporate goals and concluded that we had achieved 80%75% of our pipeline development, business and financial operations goals, particularly with respect to the progress made in

prioritizingadvancing our pipeline to extend our financial resources and direct them to continued pipeline advancement as a result of our Phase 2b METRIC Study of glembatumumab vedotin in metastatic triple-negative breast cancer not meeting its primary endpoint.clinical programs. Our Compensation Committee approved annual bonus payments of 80.0%75% to 90.0%83% of the 20182019 bonus target for Mr. Marucci, Dr. Keler, Ms. Crowley, Dr. Heath-Chiozzi and Mr. Martin, depending on the position. Further, stock options granted to our executive officers in 20182019 have exercise prices equal to 100% of the fair value on the date of grant and vest over four years, beginning with 25% vesting one year after the date of grant, then pro-rata vesting quarterly thereafter based on continued service. We believe that stock options structured in this manner encourage our executive officers to focus on increasing stockholder value and stock price appreciation over the long term and limit unnecessary risk taking behavior, while promoting retention.

        In 2018,2019, we accomplished the following significant milestones during the year:

•

Prioritized pipeline post METRIC readout:Continued progress in Phase 1 study of CDX-1140:  In April 2018, we announced that ourDose-escalation in both the monotherapy and combination with CDX-301 cohorts were completed with an identified maximum tolerated dose and recommended Phase 2b METRIC Study2 dose of our antibody drug conjugate (ADC) glembatumumab vedotin in metastatic triple-negative breast cancer did not meet its primary endpoint. Based on this result,CDX-1140 at 1.5 mg/kg—one of the highest systemic dose levels in the second quarter of 2018,CD40 agonist class. Interim data from this ongoing study presented in November 2019 demonstrated that CDX-1140 has the potential to successfully balance systemic doses for good tissue and tumor penetration with an acceptable safety profile and that the candidate has promising biological and clinical activity. The study was expanded to explore additional combination cohorts with mechanisms that we prioritized our pipeline and evaluated our operational and workforce needs to extend our financial resources and direct them to continued pipeline advancement. As previously disclosed, in linebelieve could be complementary or synergistic with this initiative and to conserve resources, we discontinued development of glembatumumab vedotin, our other ADC product candidate CDX-014 and CDX-1401.CDX-1140, including a combination with KEYTRUDA® (pembrolizumab).



•

Continued progress in Phase 2 study of CDX-3379:  Enrollment was completedIn June of 2019, data were presented that suggested that observed antitumor activity with CDX-3379 might be associated with somatic mutations in the first stage ofFAT1 and NOTCH1, NOTCH2 or NOTCH3 (NOTCH1-3) genes—genes associated with tumor suppression. Based on these biomarker observations and the clinical activity observed in the ongoing Phase 2 study, (n=13)the study was expanded to allow for an evaluation of CDX-3379 in advanced head and neck squamous cell cancer in combination with Erbitux® in Erbitux-resistant patients who have been previously treated with or are ineligiblethe utility of biomarkers for checkpoint therapy.patient selection. Enrollment is ongoing.



•

Continued progress inInitiated Phase 1 study of CDX-1140:CDX-0159:  Data from bothIn 2019, we completed all activities to support the monotherapyfiling of an Investigational New Drug (IND) application for CDX-0159 and, combination dosing cohorts with CDX-301 completed in 2018 suggested that CDX-1140 is exhibiting a desirable safety profile and demonstrating clear signs of biological activity based on biomarker analysis. Early data fromNovember 2019, the Phase 11a study were presentedwas initiated in November 2018 at the Society for Immunotherapy of Cancer (SITC) Annual Meeting. Dose dependent biological effects consistent with CD40-mediated immune activation were reported; CDX-1140 was well tolerated and no MTD had been reached.healthy volunteers.



•

Cash runway through 2020:2021:  We ended 20182019 with cash, cash equivalents and marketable securities of $94.0$64.4 million which combined withwe believe will enable us to fund our operating expenses and capital expenditure requirements into the first quarter of 2021. This guidance excludes anticipated proceeds from future sales of our common stock under the Cantor agreement are sufficient to meet estimated working capital requirements and fund planned operations through 2020.or other potential fundraising.

Independent Compensation Consultants

        The Compensation Committee believes that independent advice is important in developing Celldex's director and executive compensation programs and engages Radford, awhich is part of the Rewards Solutions practice at Aon plc, as its independent compensation consultant. In 2018, Radford reviewed both executive and director compensation. In 2017,2019, Radford provided advisory services in connection with the amendment and restatement of our 2008 Stock Option and Incentive Plan and 2004 Employee Stock Purchase Plan (the "Plans"), including an increase in the number of shares reserved for issuance under the Plan.Plans. Radford reports directly to the Committee and provides guidance on trends in executive and non-employee director compensation, the development of specific executive compensation programs, the composition of the Company's compensation peer group and other matters as directed by the Committee. The Company also participated in various Radford surveys in 2018 and 2017. During 2018 and 2017, the Company paid Radford approximately $75,600 and

$14,200, respectively, in consulting fees directly related to these services.2019. In 2018 and 2017,2019, Radford did not provide any other services to Celldex.

Data Used to Make Compensation Determinations

        In making decisions regarding the compensation of our executive officers, the Compensation Committee generally considers compensation and survey data for similarly situated executives at a comparison group of companies it considers our peer group. These comparison data are primarily used to gauge the reasonableness and competitiveness of executive compensation decisions.

        We draw upon a pool of talent that is highly sought after by large and established pharmaceutical and biotechnology companies as well as other development-stage life science companies, both within and outside our geographic areas. We believe that the compensation practices of our industry in general and of our select peer group in particular provide useful information to help us establish compensation practices that allow us to attract, retain, and motivate a highly talented executive team. We believe we must offer a compensation package to all of our officers and our other employees that is competitive with our peer group, as well as larger pharmaceutical and biotechnology companies from whom we frequently recruit. In addition, the comparator companies should be aligned with our current stage of development and have similar short and long-term growth objectives. In 2018,2019, the Compensation Committee set the target level of total executive compensation, as well as the key elements of compensation, at the 50^th percentile of our peer group, but then adjusted each of the elements based on an individual's performance and contribution to our strategic objectives. The Committee may need to adjust these levels in the future to attract or retain specific individuals.

        We review the levels of cash, equity and total compensation for all comparable officers in our peer group relative to the elements of compensation paid to our officers. In considering how these data relate to our existing compensation structure, we take into account our size, stage of development, performance and geographic location as compared to these peer companies, as well as what we know about the comparable scope of responsibilities of our officers versus those of comparable executives at such peer group companies. We used two primary market frames of reference (which we refer to as the "market") against which to compare our total executive compensation practices and levels and inform our decisions regarding compensation of our officers as follows:

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Select Peer Group—A select group of national biotechnology companies at a similar stage of development as our company with similar headcount, R&D expense, market capitalization and in most cases, similar therapeutic targets, and



•

Radford Global Life Sciences Survey—A national survey of executive compensation levels and practices that covers approximately sixty executive positions in over 600 multinational life sciences organizations.

        We do not apply a specific weighting to either data source when making compensation comparisons. Instead, we develop competitive market guidelines using these data sources.

        We review our peer group each year to ensure continued relevance as we grow and develop, and the Compensation Committee approves our peer group prior to its adoption. In May 2018, the

following peer group was approved by the Compensation Committee and used to inform our decisions

affecting executive compensation in 2018:2018. In 2019, the Compensation Committee reviewed the peer group and determined that the peer group remained an appropriate comparison for the Company.:

        ThisIn May 2018, this peer group consisted of public companies in the biopharmaceutical industry with product candidates generally in mid-stage development, with employee headcount average of 97 (range of 44 to 278), R&D expense average of $63 million and market capitalization average of $242 million. We believe that, as of May 2018,2019, this list was representative of the companies with whom we generally compete for talent.

Administration and Objectives of Our Executive Compensation Program

        The Compensation Committee of the Board of Directors, which comprises independent, non-employee directors, is responsible for establishing and administering the policies governing the compensation of our employees, including salary, bonus and stock option grants. The policy of the Compensation Committee is to compensate our employees with competitive salaries based on their level of experience and job performance. All permanent employees, including executive officers, are eligible for annual bonus awards based on achievement of our strategic corporate goals and participation in our stock option program. The stock option grants are made in accordance with our 2008 Stock Option and Incentive Plan, as amended (the "2008 Plan"). The Compensation Committee is also responsible for the administration of our 2004 Employee Stock Purchase Plan, as amended (the "2004 Plan"), in which employees participate on a voluntary basis.

        Our Compensation Committee has designed our overall executive compensation program to achieve the following objectives:

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attract and retain talented and experienced executives;



•

motivate and reward executives whose knowledge, skills and performance are critical to our success;



•

provide a competitive compensation package that aligns the interests of our executive officers and stockholders by including a significant variable component which is weighted heavily towards performance-based rewards, based upon achievement of predetermined goals;



•

ensure fairness among the executive management team by recognizing the contributions each executive makes to our success;



•

foster a shared commitment among executives by aligning our and their individual goals; and



•

compensate our executives to manage our business to meet our near-term and long-term objectives.

        We use a mix of short-term compensation (base salaries and cash incentive bonuses) and long-term compensation (equity incentive compensation) to provide a total compensation structure that is designed to achieve these objectives. We determine the percentage mix of compensation structures that

we think is appropriate for each of our executive officers. In general, the Compensation Committee believes that a substantial percentage of the compensation of our executive officers should be performance based. The Compensation Committee uses its judgment, experience and the recommendations of the chief executive officer (except for his own compensation) to determine the appropriate mix of compensation for each executive officer.

        In determining whether to adjust the compensation of any of our Named Executive Officers, we annually take into account the changes, if any, in the following:

•

market compensation levels;



•

the contributions made by each executive officer;



•

the performance of each executive officer;



•

the increases or decreases in responsibilities and roles of each executive officer;



•

the business needs of the Company with respect to each executive officer;



•

the relevance of each executive officer's experience to other potential employers; and



•

the readiness of each executive officer to assume a more significant role within the organization.

        In addition, with respect to new executive officers, we take into account their prior base salary and annual cash incentives, their expected contribution and our business needs. We believe that our executive officers should be fairly compensated each year relative to market pay levels within our industry.

Executive Compensation Components

        In order to both attract and retain experienced and qualified executives to manage us, the Compensation Committee's policy on executive compensation is to (i) pay salaries which are competitive with the salaries of executives in comparable positions in the biotechnology industry, and (ii) allow for additional incentive-based compensation through the payment of annual cash bonuses and the grant of stock-based incentive awards. This policy is designed to have a significant portion of each executive's total compensation be tied to our progress in order to incentivize the executive to fully dedicate himself or herself to achievement of corporate goals, and to align the executive's interest with those of our stockholders through equity incentive compensation.

        Our executive compensation program is primarily composed of base salary, incentive cash compensation payable on an annual basis and equity compensation. In addition, we provide our executives with benefits that are generally available to our salaried employees, including medical, dental, group life and accidental death and dismemberment insurance, short- and long-term disability coverage and our 401(k) plan. Within the context of the overall objectives of our compensation programs, we determined the specific amounts of compensation to be paid to each of our executives in 20182019 based on a number of factors including:

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our understanding of the amount of compensation generally paid by similarly situated companies to their executives with similar roles and responsibilities;



•

the roles and responsibilities of our executives;



•

the individual experience and skills of, and expected contributions from, our executives;



•

the amounts of compensation being paid to our other executives; and



•

our executives' historical compensation.

        We discuss each of the primary elements of our executive compensation in detail below. While we have identified particular compensation objectives that each element of executive compensation serves, our compensation programs complement each other and collectively serve all of our executive compensation objectives described above. Accordingly, whether or not specifically mentioned below, we believe that, as a part of our overall executive compensation, each element to a greater or lesser extent serves each of our objectives.

Base Salary

        Each executive officer (except the chief executive officer whose performance is reviewed by the Compensation Committee) has an annual performance review with the chief executive officer who makes recommendations on salary increases, promotions and stock option grants to the Compensation Committee. We have historically established base salaries for each of our executives based on many factors, including average salary increases expected in the biotechnology industry in the Boston, Massachusetts, New Haven, Connecticut and central New Jersey areas, competition in the marketplace to hire and retain executives, experiences of our Board members and leadership team with respect to salaries and compensation of executives in similarly situated companies in our industry and other similar industries, as well as additional factors which we believe enable us to hire and retain our leadership team in an extremely competitive environment. Our Compensation Committee annually reviews salary ranges and individual salaries for our executive officers and approved the following annual salaries for our Named Executive Officers:

Annual Performance-Based Cash Bonus

        We have designed our annual cash bonuses to reward our executive officers for their individual performance and their actual performance and contributions to our corporate goals for each year, as approved in advance by our Compensation Committee and Board of Directors. The corporate goals are allocated between specific product and financial performance targets. Achievement of our corporate goals was, in 2018,2019, the primary factor considered by our Compensation Committee in determining the annual bonuses for our executive officers. However, the Compensation Committee retains discretion to adjust any individual bonus based on assessment of such individual's performance. Our performance-based bonus plan emphasizes the contributions of each of our executive officers to the achievement of our corporate goals.

        At the beginning of each calendar year, the Compensation Committee establishes annual corporate performance goals and target bonuses. In 2018,2019, the Compensation Committee established target bonuses for each of our Named Executive Officers including 60% of base salary for Mr. Marucci, 40% of base salary for Dr. Keler, and 35% of base salary for Ms. Crowley, Dr. Heath-Chiozzi, and Mr. Martin. These target bonuses were consistent with the 20172018 targets. Corporate goals are proposed by management, reviewed and approved by the Compensation Committee and also approved by the Board of Directors on an annual basis. The Compensation Committee considers and assigns a relative weight to appropriately focus efforts on corporate goals that are intended to enhance shareholder value.

        The Compensation Committee reviewed the 20182019 corporate goals at meetings held in April, June and September 20182019 to gauge our levels of achievement and to assess whether the corporate goals approved earlier in the year remained relevant and complete. In December 2018November 2019 and January 2019,2020, prior to approving 20182019 incentive bonuses, the Compensation Committee evaluated our 20182019 performance by assessing if, and the extent to which, we achieved or failed to achieve the corporate goals approved by the Board of Directors for 2018.2019. The Compensation Committee considered the 20182019 performance and determined that we met 80%75% of our 20182019 corporate goals for pipeline development and business and financial operations. Our corporate goals for 20182019 and the level at which the Compensation Committee determined they were achieved are as follows:

        Prior toAt the Compensation Committee's December 2018 and January 2019 meetings,2020 meeting, Mr. Marucci reviewed in detail the performance of each executive officer, excluding himself, and considered such individual's contributions to our success in 2018.2019. Mr. Marucci's bonus recommendations were based on such individual performance assessments and the fact that the Company achieved 80%75% of its predetermined corporate goals in 20182019 and each employee, including the executive officers, contributed to our success in achieving the 20182019 corporate goals.

        The Compensation Committee discussed Mr. Marucci's recommendations for the Named Executive Officers and reviewed Mr. Marucci's performance for fiscal 2018.2019. Based on Mr. Marucci's recommendations for each of the Named Executive Officers, the Compensation Committee's review of Mr. Marucci's performance and the Compensation Committee's determination that 80%75% achievement of the corporate goals for 2018,2019, the Compensation Committee approved annual bonus payments of 80.0%75% to 90.0%83% of the 20182019 bonus target for Mr. Marucci, Dr. Keler, Ms. Crowley, Dr. Heath-Chiozzi and Mr. Martin, depending on the position

        The Compensation Committee determined that annual incentive bonuses paid to the Named Executive Officers for 2018,2019, were fair, reasonable and appropriate based on the factors described above.

Equity Compensation

        We also use stock options and equity-based incentive programs to attract, retain, motivate and reward our executive officers. Through our equity-based grants, we seek to align the interests of our executive officers with our stockholders, reward and motivate both near-term and long-term executive performance and provide an incentive for retention. Our decisions regarding the amount and type of equity incentive compensation and relative weighting of these awards among total executive compensation have been based on our understanding of market practices of similarly situated companies and our negotiations with our executives in connection with their initial employment or promotion.

        We have adopted an equity grant policy that formalizes how we grant equity awards by setting a regular schedule for granting equity awards in connection with the hiring or promotion of any of our employees, granting annual equity awards and granting equity awards to non-employee directors. Such policy also outlines grant approval requirements and specifies the vesting schedule and exercise prices for restricted stock units and stock option awards. We believe that this policy will mitigate the risk that issues or concerns would be raised in the future regarding the timing of grants of equity awards to our officers, directors and employees.

        All such grants to our Named Executive Officers are subject to prior approval by the Compensation Committee at a regularly scheduled meeting during the year. The date of grant and the fair market value of the award are based upon the date of the Compensation Committee meeting approving such grant. When granting equity-based awards, the Compensation Committee considers a number of factors in determining the amount of equity incentive awards, if any, to grant to our executives, including:

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the existing levels of stock ownership among the executive officers relative to each other and to our employees as a whole;



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previous grants of stock options to such executive officers;



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vesting schedules of previously granted options;



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the performance of the executives and their contributions to our overall performance;



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an outside survey of stock option grants and restricted common stock awards in the biotechnology industry;



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an internally prepared survey of similarly situated biotechnology companies' proxy statements;



•

personal knowledge of the Compensation Committee members regarding executive stock options and restricted common stock awards at comparable companies;



•

the financial statement impact of stock option awards on our results of operations; and



•

the amount and percentage of our total equity on a diluted basis held by our executives.

        Equity compensation awards to our Named Executive Officers primarily consist of stock option awards. Stock option awards provide our executive officers with the right to purchase shares of our common stock at a fixed exercise price typically for a period of up to ten years, subject to continued employment with us. Stock options are earned on the basis of continued service to us and generally vest over four years, beginning with 25% vesting one year after the date of grant, then pro-rata vesting quarterly thereafter. All historical option grants were made at what our Compensation Committee and Board of

Directors determined to be the fair market value of our shares of our common stock on the respective grant dates.

        On June 13, 2018,19, 2019, the Compensation Committee awarded stock options to all qualified employees, including stock options to purchase 71,665100,000 shares, 25,99960,000 shares, 20,00043,000 shares, 18,33243,000 shares, and

26,332 43,000 shares of our common stock to each of Mr. Marucci, Dr. Keler, Ms. Crowley, Dr. Heath-Chiozzi and Mr. Martin, respectively. All share amounts reflect the one for fifteen reverse stock split which became effective February 8, 2019.

Other Benefits

        We believe that establishing competitive benefit packages for our employees is an important factor in attracting and retaining highly qualified personnel. Executive officers are eligible to participate in all of our employee benefit plans, such as medical, dental, group life and accidental death and dismemberment insurance, short- and long-term disability coverage and our 401(k) plan, in each case on the same basis as other employees. We provide a matching contribution under our 401(k) plan.

Employment Agreements and Post-Termination Compensation and Benefits

        We depend greatly on the intellectual capabilities and experience of our key executives. Our success is dependent on our ability to attract and retain highly skilled executives with significant experience in the biotechnology industry, particularly as we expand our activities in clinical trials, the regulatory approval process and sales and manufacturing. Therefore we enter into employment agreements with each of our Named Executive Officers.

        In general, each employment arrangement provides for cash severance, 100% acceleration of any unvested options, restricted stock and/or other equity awards and continuation of certain employee benefits in the event that an executive's employment is terminated within a one year period immediately following a change of control either without cause or by the executive for good reason. The cash severance consists of a single lump sum payment equal to (i) twenty-four (24) times the executive's highest monthly base compensation paid hereunder during the preceding twenty-four month period, plus (ii) 150% (200%, in the case of Mr. Marucci) of the highest one-year annual bonus actually received by the executive during the preceding two full fiscal years prior to the date of termination. We use a "double trigger" with respect to benefits that are to be provided in connection with a change of control. A change of control does not itself trigger benefits; rather, benefits are paid only if the employment of the executive is terminated by us other than for cause, death or disability or by the executive for good reason during the one year period immediately following the change of control. We believe a "double trigger" benefit maximizes shareholder value because it prevents a windfall to executives in the event of a change of control in which the executive retains significant responsibility as defined in his or her individual agreement, while still providing our executives appropriate incentives to cooperate in negotiating any change of control that may put their jobs at risk.

        In addition to the benefits that only accrue in connection with a change of control, our agreements with the Named Executive Officers provide for cash severance, 25% acceleration of unvested options (in the case of Mr. Marucci, Dr. Keler and Ms. Crowley), restricted stock and/or other equity awards and continuation of certain employee benefits if we terminate their employment with us without cause or they terminate their employment with us for good reason, as such terms are defined in the applicable agreement with the executive officer. The cash severance consists of a lump sum cash payment equal to 100% (200% in the case of Mr. Marucci) of the executive's then existing base salary. A further discussion of the terms and projected payments under each of these agreements is set forth below under the headingPotential Payments upon Termination of Employment or Change in Control.

Committee Consideration of the Company's 20182019 Shareholder Advisory Vote on Executive Compensation

        At our 20182019 Annual Meeting of Shareholders, approximately 85%83% of the shares voted at the meeting approved, on an advisory basis, the compensation of the Named Executive Officers. Given that a majority of the shares voted approved the 'say on pay' advisory proposal, the Committee did not implement specific changes and continued with its performance-based compensation philosophy and its balanced approach to various components of its compensation program. However, the Compensation Committee does monitor the results of the annual advisory 'say-on-pay' proposal and refers to such results as one of many factors considered in connection with the discharge of its responsibilities, although the Committee does not assign a quantitative weighting to any such factors.

Summary Compensation Table

        The following summary compensation table reflects certain information concerning compensation for services in all capacities awarded to, earned by or paid during the years ended December 31, 2019, 2018 2017 and 20162017 to (i) our Chief Executive Officer, (ii) our Chief Financial Officer, and (iii) our three most highly compensated executive officers, other than the Chief Executive Officer and Chief Financial Officer, who were serving as executive officers as of December 31, 20182019 (collectively, the "Named Executive Officers").

Grants of Plan-Based Awards

        The following table provides information on stock options and stock awards granted in 20182019 to each of our Named Executive Officers. All share and per share amounts reflect the one for fifteen reverse stock split which became effective February 8, 2019.

Outstanding Equity Awards at Fiscal Year-End

        The following table sets forth certain information regarding the stock option grants and stock awards to our Named Executive Officers at December 31, 2018.2019. All share and per share amounts reflect the one for fifteen reverse stock split which became effective February 8, 2019.

Option Exercises and Stock Vested

        The following table sets forth certain information regarding the number of option exercises in fiscal 20182019 and the number of shares of stock issued under the 2008 Plan that vested in fiscal 20182019 and the corresponding amounts realized by our Named Executive Officers.

Employment Agreements

        The terms and conditions of the employment agreements of Mr. Marucci, Dr. Keler, Ms. Crowley, Dr. Heath-Chiozzi and Mr. Martin are governed by written employment contracts which became effective on January 1, 2018. The employment agreements provide, among other things, for:

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current annual base salary ($608,249632,579 in the case of Mr. Marucci, $434,453$451,831 in the case of Dr. Keler, $343,330$358,830 in the case of Ms. Crowley, $370,000$386,250 in the case of Dr. Heath-Chiozzi and $365,000$385,000 in the case of Mr. Martin) or such greater amount as may from time to time be determined by the Board of Directors or the Compensation Committee thereof;



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eligibility for an annual bonus with a current bonus target (60% of base salary in the case of Mr. Marucci, 40% of base salary in the case of Dr. Keler and 35% of base salary in the case of Ms. Crowley, Dr. Heath-Chiozzi and Mr. Martin);



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a lump sum severance payment equal to 100% (200% in the case of Mr. Marucci only) of the executive's then-existing annual base salary in the event that the executive's employment is terminated without cause or the executive resigns "for good reason" (as defined in the employment agreement) and 25% accelerated vesting of any unvested equity awards (in the case of Mr. Marucci, Dr. Keler and Ms. Crowley); and



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accelerated vesting of any unvested equity awards (as defined in the employment agreement) and a lump sum cash payment equal to twenty-four (24) times the executive's highest monthly base compensation (not including bonus) during the twenty-four month period preceding the date of termination plus 150% (200% in the case of Mr. Marucci only) of the highest one-year annual bonus actually received by the executive during the two full fiscal years preceding the date of termination in the event of termination without cause or resignation "for good reason" by the executive within one year immediately following a change in control (as defined in the employment agreement).

        The employment agreements had an initial term through December 31, 2018 and shall automatically renew for additional one year terms unless either party gives ninety (90) days prior written notice of its intent not to renew. The Company may terminate the employment agreements without cause, on 90-days' prior notice, or for cause, subject to a 30-day cure period in certain circumstances.

Pension Benefits

        None of our Named Executive Officers participate in qualified or nonqualified defined benefit plans sponsored by us.

Nonqualified Deferred Compensation

        None of our Named Executive Officers are covered by a defined contribution or other plan that provides for the deferral of compensation on a basis that is not tax-qualified.

Potential Payments Upon Termination of Employment or Change in Control

        Our Named Executive Officers have provisions in their employment agreements regarding severance upon certain termination events or acceleration of stock options in the event of our change of control or termination following a change of control. These severance and acceleration provisions are described in "Employment Agreements," and certain estimates of these change of control benefits are provided in the tables below.

        The following table describes the potential payments and benefits upon employment termination for our Named Executive Officers as if their employment had terminated as of December 31, 2018.2019.

CEO Pay Ratio

        As required by Section 953(b) of the Dodd-Frank Wall Street Reform and Consumer Protection Act and Item 402(u) of Regulation S-K, we are required to disclose the ratio of our median employee's annual total compensation to the annual total compensation of our principal executive officer.

        The purpose of this new disclosure is to provide a measure of the equitability of pay within our company. We believe our compensation philosophy and process yield an equitable result for all of our employees. During fiscal 2018,2019, the principal executive officer of Celldex was our Chief Executive Officer, Anthony S. Marucci. For 2018,2019, the annual total compensation, using the same methodology we use for our named executive officers as set forth in the summary compensation table, for Mr. Marucci was $1,385,351,$1,128,320, and for our median employee was $112,534,$115,473, resulting in an estimated pay ratio of 1210 to 1.

        In accordance with Item 402(u) of Regulation S-K, we identified the median employee by (i) determining our employee population as of December 31, 2018 (including all full-time, part-time, salaried, hourly, and seasonal employees, but excluding Mr. Marucci), (ii) calculating the total compensation for each employee for fiscal 2018 by aggregating (A) annual base salary for salaried employees (or hourly rate multiplied by expected annual work schedule, for hourly employees), (B) the bonus for 2018, and (C) the estimated accounting value of any equity awards granted during 2018, and (iii) ranking this compensation measure for our employees from lowest to highest. We do not believe that there has been any change in our employee population or employee compensation arrangements for fiscal 2019 that would result in a significant change to our pay ratio disclosure. As such, and as permitted by Item 402(u) of

Regulation S-K, we are using the same median employee for our pay ratio disclosure that we identified for our pay ratio disclosure for fiscal 2018.

        The pay ratio reported above is a reasonable estimate calculated in a manner consistent with SEC rules based on our internal records and the methodology described above. Because the SEC rules for identifying the median compensated employee and calculating the pay ratio based on that employee's annual total compensation allow companies to adopt a variety of methodologies, to apply certain exclusions, and to make reasonable estimates and assumptions that reflect their employee populations and compensation practices, the pay ratio reported by other companies may not be comparable to the pay ratio reported above, as other companies have different employee populations and compensation practices and may utilize different methodologies, exclusions, estimates and assumptions in calculating their own pay ratios.

Director Compensation

        Effective June 2018, Directors who are not our employees are each entitled to receive a retainer fee of $40,000 each fiscal year ("Annual Retainer"). The ChairmanChair of the Board is entitled to receive an annual retainer fee of $30,000 in addition to his or her Annual Retainer and any retainer for committee service. The Chairperson of the Audit Committee, Compensation Committee and Nominating and Corporate Governance Committee of the Board of Directors is entitled to receive an annual retainer fee of $15,000, $12,500 and $8,000, respectively, in addition to his or her Annual Retainer. Each committee member of the Audit Committee, Compensation Committee and Nominating and Corporate Governance Committee (other than the Chairperson of a committee) will receive an annual retainer of $7,500, $6,250 and $4,000, respectively, in addition to his or her Annual Retainer. Stipends and retainers are paid in advance on a quarterly basis. The Directors shall be reimbursed for necessary travel and business expenses as incurred but will not receive any additional fees for attending meetings or calls of the Board of Directors.

        All of the following share and per share amounts reflect the one for fifteen reverse stock split which became effective February 8, 2019. In June 2018,2019, all non-employee directors received an annual stock option grant to purchase 4,6664,500 shares of the Company's common stock following the Annual Meeting of Stockholders. As of December 31, 2018, our non-employee directors had the following stock options outstanding: Larry Ellberger—7,418, Keith L. Brownlie—5,999, Herbert J. Conrad—7,418, James J. Marino—5,999, Harry H. Penner, Jr.—7,418 and Karen L. Shoos—7,418.

        The following table summarizes the annual compensation for our non-employee directors during 2018.2019.