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

Filed by the Registrant  x☒                            Filed by a Party other than the Registrant  ¨☐

Check the appropriate box:

OpexaAcer Therapeutics 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)all boxes that apply):

OPEXA

ACER THERAPEUTICS INC.

2635 TECHNOLOGY FOREST BLVD.ONE GATEWAY CENTER, SUITE 356

THE WOODLANDS, TEXAS 77381300 WASHINGTON STREET

NEWTON, MASSACHUSETTS 02458

April 11, 201614, 2023

To Our Shareholders:Stockholders:

You are cordially invited to attend the Annual Meeting of ShareholdersStockholders of OpexaAcer Therapeutics Inc. on Monday,Friday, May 16, 201619, 2023 at 10:11:00 a.m. CentralEastern Time. The meetingAnnual Meeting will be held at 2 Houston Center, 909 Fannin, Suite 2000, Houston, Texas 77010.

Information abouta completely virtual meeting of stockholders conducted via live audio webcast to provide a safe and convenient experience for our stockholders. You will be able to attend the Annual Meeting including matters on which shareholders will act, may be found invia the Notice of Annual Meeting and Proxy Statement accompanying this letter. We look forward to greeting in person as many of our shareholders as possible.Internet at https://www.cstproxy.com/acertx/2023.

It is important that your shares be represented and voted at the virtual meeting. Whether or not you plan to attend the Annual Meeting, please complete, sign, date, and promptly return the accompanying proxy in the enclosed envelope or use one ofvote by Internet or by following the instructions on your voting methods described in the attached materials.instruction form. Returning the proxy does NOT deprive you ofor voting by Internet or vote instruction form will ensure your right to attend the Annual Meeting. If you decide to attendrepresentation at the Annual Meeting and wish to change your proxy vote,regardless of whether you may do so automatically by voting in person atattend the meeting.virtual Meeting. Please note, however, that if your shares are held of record by a broker, bank or other nominee and you wish to attend and vote in person at the meeting, you must obtain from the record holder a legal proxy issued in your name.

Thank you for your ongoing support and continued interest in Acer.

Sincerely yours,

/s/ Chris Schelling

Chris Schelling

Neil K. Warma,Founder, President and Chief Executive Officer

OPEXAACER THERAPEUTICS INC.

2635 TECHNOLOGY FOREST BLVD.ONE GATEWAY CENTER, SUITE 356

THE WOODLANDS, TEXAS 77381300 WASHINGTON STREET

NEWTON, MASSACHUSETTS 02458

NOTICE OF ANNUAL MEETING OF SHAREHOLDERSSTOCKHOLDERS

TO BE HELD MAY 16, 201619, 2023

The Annual Meeting of shareholdersstockholders of OpexaAcer Therapeutics Inc. (the “Company”) will be held on Monday,Friday, May 16, 2016,19, 2023, at 10:11:00 a.m. Central Time,Eastern Time. The Annual Meeting will be a completely virtual meeting of stockholders conducted via live audio webcast to provide a safe and convenient experience for our stockholders. You will be able to attend the Annual Meeting via the Internet at 2 Houston Center, 909 Fannin, Suite 2000, Houston, Texas 77010. Our shareholdershttps://www.cstproxy.com/acertx/2023. Stockholders are being asked to vote to:

These business items are described more fully in the Proxy Statement accompanying this Notice.

Only shareholdersstockholders who owned common stock at the close of business on March 28, 201630, 2023 can vote at this meeting or any adjournments or postponements that may take place. All shareholdersstockholders are cordially invited to attend the meeting in person.virtual meeting. However, to assure your representation at the meeting, you are urged to mark, sign and return the enclosed proxy as promptly as possible in the postage-prepaid envelope for that purpose or use one of the voting methods described in the attached materials.vote by Internet or by vote instruction form. Your stock will be voted in accordance with the instructions you have given. Any shareholderstockholder attending the virtual meeting may vote in personelectronically even if he or she has previously returned a proxy. Please note, however, that if your shares are held of record by a broker, bank or other nominee and you wish to attend and vote in person at the meeting, you must obtain from the record holder a legal proxy issued in your name.

By Order of the Board of Directors,

/s/ Chris Schelling

Chris Schelling

Neil K. Warma,Founder, President and Chief Executive Officer

Dated: April 11, 201614, 2023

The Board of Directors solicits the enclosed proxy. Your vote is important no matter how large or small your holdings.stockholdings. To assure your representation at the meeting, please complete, sign, date and promptly mail the enclosed proxy card in the postage-paid envelope provided or use one of the voting methods described in the attached materials.vote by Internet or by vote instruction form.

Important Notice Regarding the Availability of Proxy Materials for the ShareholderStockholder Meeting to be held on May 16, 2016:19, 2023: This Proxy Statement and our 20152022 Annual Report on Form 10-K are available at: at https://www.cstproxy.com/opexatherapeutics/2016acertx/2023

OPEXAACER THERAPEUTICS INC.

PROXY STATEMENT

ANNUAL MEETING OF SHAREHOLDERSSTOCKHOLDERS

TO BE HELD MAY 16, 201619, 2023

INFORMATION CONCERNING SOLICITATION AND VOTING

General

The enclosed proxy is solicited on behalf of our Board of Directors (“Board”) for use at the annual meeting of shareholdersstockholders to be held on Monday,Friday, May 16, 2016,19, 2023, at 10:11:00 a.m. CentralEastern Time (the “Annual Meeting”), or at any adjournment or postponement of this meeting,the Annual Meeting, for the purposes set forth in this Proxy Statement and in the accompanying Notice of Annual Meeting of Shareholders.Stockholders. The Annual Meeting will be held virtually at 2 Houston Center, 909 Fannin, Suite 2000, Houston, Texas 77010.https://www.cstproxy.com/acertx/2023. There will be no physical location. The meeting will only be conducted via an audio webcast. We intend to mail this Proxy Statement and accompanying proxy card to shareholdersstockholders on or about April 11, 2016. 14, 2023.

The Board of Opexa Therapeutics, Inc., a Texas corporation, prepared this Proxy Statement for the purpose of soliciting proxies for our Annual Meeting of Shareholders.Stockholders. The terms “we,” “our,” the “Company” or “Opexa,“Acer,” refer to OpexaAcer Therapeutics Inc., a Delaware corporation.

Availability of Annual Report on Form 10-K

Accompanying this Proxy Statement is our Annual Report on Form 10-K for the fiscal year ended December 31, 20152022 as filed with the Securities and Exchange Commission (the “SEC”). We make available, free of charge through our website (www.opexatherapeutics.com)(www.acertx.com), our annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K and amendments to those reports filed or furnished pursuant to Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), as soon as reasonably practicable after such documents are electronically filed with or furnished to the SEC. These reports can be found under “SEC Filings” through the “Investor Relations” section of our website. We will provide to any shareholderstockholder without charge, upon the written request of that shareholder,stockholder, a copy of our Annual Report on Form 10-K (without exhibits), including financial statements and financial statement schedules. Such requests should be addressed to Investor Relations, OpexaAcer Therapeutics Inc., 2635 Technology Forest Blvd., The Woodlands, Texas 77381.One Gateway Center, Suite 356, 300 Washington Street, Newton, Massachusetts 02458.

Voting

Before the meeting, you may vote your shares if they are registered directly in your name with our transfer agent, Continental Stock Transfer & Trust Company, by (i) completing, signing, dating and returning the enclosed proxy card (i) by mail in the postage paid envelope provided so that it is received before the polls close at the Annual Meeting, or (ii) using the Internet to vote your proxy 24 hours a day, 7 days a week, so that your electronic vote is received by faxing11:59 p.m., Eastern Time, on May 18, 2023. If you would like to vote electronically and are a stockholder of record, you may do so by using the control number which appears on your proxy card to (281) 872-8585.log on and follow the instructions included with your proxy card. You are encouraged to vote electronically by Internet. If you vote by Internet, you do not need to return your proxy card. Please follow the directions on your proxy card carefully.Stockholders are encouraged to vote and submit proxies in advance of the Annual Meeting by Internet or mail as early as possible to avoid processing delays.

If your shares are held in a brokerage account in the name of a broker, bank broker or other nominee (this is called “street name”), then you are the beneficial owner of the shares and these proxy materials are being forwarded to you by that organization. The organization holding your account is considered the shareholderstockholder of record for

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purposes of voting at the Annual Meeting. You have the right to direct your broker, bank or brokernominee on how to vote the shares in your account, and you may also be able to vote by telephone or via the Internet depending on the voting procedures used by your broker.broker, bank or nominee. You may receive a separate voting instruction form with this Proxy Statement, orand you may need to contact your broker, bank or other nominee to determine whether you will be able to vote electronically using the telephone or Internet. If you hold shares as a beneficial owner, please follow the voting instructions provided by your bank, broker or other nominee for any deadline to return your vote instruction form.

Whether or not you plan to attend the meeting, we encourage you to vote your shares before the meeting. You may vote your shares at the meeting if you attend in person,online, even if you previously submitted a proxy card or voted by telephone or Internet. Whether or not you plan to attend the meeting, however, we encourage you to vote your shares by proxy before the meeting. Please note that if your shares are held in “street name” and you wish to vote at the meeting, you will not be permitted to do so unless you first obtain a legal proxy issued in your name from the broker, bank or nominee that holds your shares.

Attendance and Voting at the Virtual Annual Meeting

The Annual Meeting will be a completely virtual meeting of stockholders conducted via live audio webcast to provide a safe and convenient experience for our stockholders. In addition, we believe that the virtual meeting format will expand stockholder access and participation. You will not be able to attend the Annual Meeting in person.

You are entitled to attend the virtual Annual Meeting, vote your shares electronically at the meeting and submit questions only if you were a stockholder of record as of the record date for the Annual Meeting, March 30, 2023, or if you hold a valid legal proxy for the Annual Meeting. The live audio webcast of the Annual Meeting will begin promptly at 11:00 a.m. Eastern Time. Stockholders participating in the virtual meeting will be in listen-only mode and will not be able to speak during the webcast. Online access to the audio webcast will open approximately 15 minutes prior to the start of the Annual Meeting to allow time for our stockholders to log in and test their device audio system. We encourage our stockholders to access the meeting in advance of the designated start time.

Registered Stockholders

If your shares are registered in your name with our transfer agent, Continental Stock Transfer & Trust, and you wish to attend the virtual Annual Meeting or vote at the Annual Meeting, go to https://www.cstproxy.com/acertx/2023 and enter the control number included on your proxy card, and click on the “Click here to preregister for the online meeting” link at the top of the page. Prior to the start of the meeting, you will need to log back into the meeting site using your control number. Pre-registration is recommended but is not required in order to attend.

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

Beneficial stockholders who wish to attend the online-only virtual Annual Meeting or vote at the Annual Meeting must obtain a legal proxy by contacting their account representative at the broker, bank or other nominee that holds their shares, and then e-mail a copy (a legible photograph is sufficient) of their legal proxy to our transfer agent, Continental Stock Transfer & Trust, proxy@continentalstock.com. Beneficial stockholders who e-mail a valid legal proxy will be issued a meeting control number that will allow them to register to attend and participate in the online-only meeting. After contacting Continental, a beneficial holder will receive an e-mail prior to the meeting with a link and instructions for entering the virtual meeting. Beneficial stockholders should contact Continental at least five business days prior to the meeting date.

Submission of Questions at the Virtual Annual Meeting

An online portal will be available to our stockholders at https://www.cstproxy.com/acertx/2023 for the Annual Meeting. By accessing this portal, stockholders will be able to submit questions in advance or at the

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Annual Meeting. To demonstrate proof of stock ownership, you will need to log on to the portal by entering the control number included on your proxy card or the meeting control number provided by Continental to submit questions. We intend to answer questions submitted during the meeting that are pertinent to the Company and the items being brought before stockholder vote at the 2023 Annual Meeting, as time permits.

Technical Assistance Provided Before and During the Virtual Annual Meeting

Beginning 15 minutes prior to the start of and during the virtual Annual Meeting, we will have a support team ready to assist stockholders with any technical difficulties they may have accessing or hearing the virtual meeting. If you encounter any difficulties accessing the virtual meeting during the check-in or meeting time, you should call our support team at (917) 262-2373.

Revocability of Proxies

Any proxy given pursuant to this solicitation may be revoked by the person giving ita stockholder of record at any time before its use by delivering to the Secretary of Opexa, at the address of our executive offices noted above,Acer, One Gateway Center, Suite 356, 300 Washington Street, Newton, Massachusetts 02458, written notice of revocation or a duly executed proxy bearing a later date or by attending the virtual Annual Meeting and voting electronically. If you are a “street name” holder, your broker, bank or other nominee can provide instructions explaining how you may change or revoke your voting instructions. Logging in person. Attendancefor virtual attendance at the Annual Meeting alone will not by itself, revoke ayour proxy.

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Quorum, Abstentions and Broker Non-Votes

Our common stock is the only type of security entitled to vote at the Annual Meeting. Only shareholdersstockholders of record at the close of business on March 28, 2016 (the “Record Date”)30, 2023 will be entitled to notice of and to vote at the virtual Annual Meeting. As of the Record Date,record date, there were 6,982,90923,421,534 shares of common stock outstanding and entitled to vote. Each holder of record of shares of common stock on the Record Daterecord date will be entitled to one vote for each share held on all matters to be voted upon at the Annual Meeting. Shares of common stock may not be voted cumulatively.

Proxies properly executed, duly returned to us and not revoked will be voted in accordance with the specifications made. Where no specifications are given, such proxies will be voted:

It is not expected that any matters other than those referred to in this Proxy Statement will be brought before the Annual Meeting. If, however, any matter not described in this Proxy Statement is properly presented for action at the Annual Meeting, the person named as proxy in the enclosed form of proxy will have discretionary authority to vote according to his or her own discretion.

The required quorum for the transaction of business at the virtual Annual Meeting is a majority of the issued and outstanding shares of our common stock entitled to vote at the Annual Meeting, whether present in persononline or represented by proxy. Our bylaws provide that unless otherwise provided by law or by our Certificate of Incorporation, all matters other than the election of directors shall be decided by the affirmative vote of a majority of the shares of stock representedentitled to vote present in person or represented by proxy at the Annual Meeting. Shares of common stock represented by a properly signed and returned proxy will be treated as present at the virtual Annual Meeting for purposes of determining a quorum, regardless of whether the proxy is marked as casting a vote or abstaining.

The term “broker non-vote” refers to shares held by a brokerage firm, bank or other nominee (for the benefit of its client) that are represented at the meeting, but with respect to which such broker or nominee is not instructed to vote on a particular proposal and does not have discretionary authority to vote on that proposal.

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Brokers, banks and nominees do not have discretionary voting authority on certain non-routine matters and accordingly may not vote on such matters absent instructions from the beneficial holder. Discretionary items are proposals considered “routine” under the rules of the New York Stock Exchange (also applicable to NASDAQ-listedNasdaq-listed companies), such as the ratification of the appointment of our independent auditors. registered public accounting firm. Non-routine items for which brokers, banks and nominees do not have discretionary voting power include the election of directors, the approval of our Amended and Restated 2010 Stock Incentive Plan and the approval of the compensation of our Named Executive Officers.directors.

If you hold your shares in “street name”street name or through a broker, bank or other nominee, it is important that you direct your broker how to vote your shares.

Vote Required

Proposal 1. Directors are elected by a plurality of the affirmative votes cast by those shares of common stock present, in person, or represented by proxy, and entitled to vote at the virtual Annual Meeting. This means the sixfive nominees for directorsdirector receiving the highest number of affirmative votes will be elected. Proxies marked to “Withhold Authority” will not affect the election of a candidate who receives a plurality of votes. The election of directors is a matter on which a broker, bank or other nominee is generally not empowered to vote using discretion, and therefore, broker non-votes may exist but will have no effect on the outcome of the election of candidatesnominees for directors. Shareholdersdirector. Stockholders may not cumulate votes in the election of directors. We urge you to provide any necessary voting instructions to your broker, bank or nominee if you hold your shares in street name in order for your vote to be considered for this proposal.

Proposal 2. Approval of our Amended and Restated 2010 Stock Incentive PlanProposal 2 (i.e., the ratification of the appointment of the independent registered public accounting firm) requires the affirmative vote of the holders of a majority of the voting powershares of stock entitled to vote present in person or represented by proxy and voting at the Annual Meeting. This means that a majority of the shares represented at the Annual Meeting must be voted “for” the proposal for it to be approved. Abstentions will have the same effect as a vote “against” this proposal. Proposal 2 is a matter on which a broker, or other nominee is generally not empowered to vote using discretion, and therefore, abstentions and broker non-votes may exist with respect to this proposal. Accordingly, we urge you to provide any necessary voting instructions to your broker or nominee if you hold your shares in street name in order for your vote to be considered for this proposal.

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Proposal 3. Because the proposal to approve the compensation of our Named Executive Officers asks for a non-binding, advisory vote, there is no “required vote” that would constitute approval. We value the opinions expressed by our shareholders in this advisory vote, and our Compensation Committee, which is responsible for overseeing and administering our executive compensation programs, will consider the outcome of the vote when designing our compensation programs and making future compensation decisions for our Named Executive Officers. Abstentions and broker non-votes will not affect the outcome of this advisory vote.

Proposal 4. Ratification of the appointment of MaloneBailey, LLP as our independent auditors requires the affirmative vote of the holders of a majority of the voting power present or represented by proxy and voting at the Annual Meeting. The ratification of the appointment of the independent auditors is a matter on which a brokerbank or other nominee is generally empowered to vote, and therefore, broker non-votes are not expected to exist with respect to this proposal. Abstentions will not affect the outcome.

Solicitation

The cost of soliciting proxies will be borne by Opexa.the Company. In addition to soliciting shareholdersstockholders by mail and through our regular employees, we will request that brokers, banks and brokers and other personsnominees representing beneficial owners of the shares forward the proxy solicitation material to such beneficial owners, and we may reimburse these parties for their reasonable out-of-pocket costs. We may use the services of our officers, directors and others to solicit proxies, personally or by telephone, facsimile or electronic mail, without additional compensation. We have retained Advantage Proxy to assist us in soliciting proxies using the means referred to above. We will pay the fees of Advantage Proxy, which we expect to be approximately $5,500,$6,000, plus reimbursement of out-of-pocket expenses.

If you need additional copies of this Proxy Statement or the enclosed proxy card, or if you have other questions about the proposals or how to vote your shares or to obtain directionshow to attend the virtual meeting, and vote in person, you may contact our proxy solicitor, Advantage Proxy, at (877) 870-8565 (toll free).

ShareholderStockholder Proposals

Proposals of shareholdersstockholders that are intended to be presented at our 20172024 Annual Meeting of ShareholdersStockholders and the proxy materials for such meeting must comply with the requirements of SEC Rule 14a-8 and must be received by our Secretary at the address of our principal executive offices noted above no later than March 25, 2017December 16, 2023 in order to be included in the Proxy Statementproxy statement and proxy materials relating to that meeting. Moreover, with respect to any

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For a proposal by a shareholder not seekingstockholder or a director nomination to havebe properly brought before the proposal included in the Proxy Statement but seeking to have the proposal considered at our next annual meeting, pursuant to our bylaws, such shareholderstockholder must provide written notice of such proposal or director nomination so that it is received by our Secretary at our principal executive offices not less than 5090 days nor more than 90120 days prior to the anniversary of the date of suchthe proxy statement for the prior year’s annual meeting; provided, however, that in the event that less than 75 days’ notice ofno annual meeting was held in the previous year or the date of the annual meeting is given to shareholders, more than 30 days before or after the first anniversary of the preceding year’s annual meeting,notice by the shareholder to be timelystockholder must be received noby the Secretary of the corporation not later than the close of business on the 15thlater of the 90th day prior to such annual meeting and the 10th day following the dateday on which noticepublic announcement of the date of such meeting is first made by means of a press release reported by the annual meeting was mailed. IfDow Jones News Service, Associated Press or a comparable national news service or in a document publicly filed by us with the shareholder failsSEC. The stockholder’s notice must set forth, as to giveeach proposed matter, the information required by our bylaws. For director nominations, information required by our bylaws to be in the notice by this date, theninclude the persons who are appointed as proxies may exercise their discretionary voting authority with respect to such proposals, even ifname and contact information for the shareholders have not been advisedcandidate and the person making the nomination and other information about the nominee and the person making the nomination that must be disclosed in proxy solicitations under Section 14 of the proposal. In addition, shareholdersSecurities Exchange Act of 1934 and the related rules and regulations under that Section.

Stockholders must comply in all respects with the rules and regulations of the SEC then in effect and the procedural requirements of our bylaws.

Dissenter’s Rights

Neither Texas law nor our Restated Certificate In addition, stockholders who intend to solicit proxies in support of Formation or bylawsdirector nominees other than the Company’s nominees must also provide our shareholders with dissenters’ rights in connection withnotice that sets forth the matters described in this Proxy Statement.

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PROPOSAL 1

ELECTION OF DIRECTORS

The Board of Directors currently consists of sixfive members, each with a term expiring at the 2016 Annual Meeting. The Nominating and Corporate Governance Committee of the Board has recommended, and the Board has nominated, the sixfive incumbent directors for election at the Annual Meeting. TheUnless otherwise directed, the shares represented by the enclosed proxy will be voted for the election as directors of the sixfive nominees named below to serve until the 2017 Annual Meeting2024 annual meeting or until their successors have been duly elected and qualified. All of the nominees have indicated to us that they will be available to serve as directors. If any of the nominees becomesbecome unavailable for any reason or if a vacancy should occur before the election (which events are not anticipated), the shares represented by the enclosed proxy may be voted for such other person or persons recommended by the Board as may be determined by the holders of the proxy. There are no family relationships among our executive officers and directors.

Director Nominees

Individuals nominated for election are:at the Annual Meeting and their ages as of April 14, 2023 are as follows:

Biographical information for our director nominees is set forth below:

Timothy C. BarabeStephen J. Aselage has served as Chairman of the Board since the completion of the 2017 merger of Opexa Therapeutics, Inc. (“Opexa”) (Nasdaq: OPXA), a Director since March 2014. He retiredbiotechnology company, and private Acer. From October 2015 until the merger, Mr. Aselage served as the Chairman of private Acer’s Board of Directors. Most recently, he was the Chief Executive Officer of Travere Therapeutics, Inc. (“Travere Therapeutics”) (formerly known as Retrophin, Inc.) (Nasdaq: TVTX), a biopharmaceutical company, from November 2014 until his retirement in 2013January 2019, and a member of its board of directors from October 2012 to May 2022. From May 2014 to November 2014, Mr. Aselage served as the Chief Operations Officer and interim Chief Executive Officer of Travere Therapeutics. Prior to joining Travere Therapeutics, he held a variety of roles at BioMarin Pharmaceutical Inc. (“BioMarin”) (Nasdaq: BMRN), a Nasdaq-listed biotechnology company, as Executive Vice President and Chief FinancialBusiness Officer of Affymetrix, Inc. Previously, from July 2006 until March 2010, he wasDecember 2009 to September 2012 and Senior Vice President of Global Commercial Development from July 2005 to December 2009. He has also held leadership roles at Cell Therapeutics, Inc. (“Cell Therapeutics”) (Nasdaq: CTIC), a company that focuses on development, acquisition, and Chief Financial Officercommercialization of Human Genomedrugs for the treatment of cancer, SangStat Medical Corporation, a biotechnology company, Advanced Tissue Sciences, Inc., a leading tissue engineering company, and Genentech, Inc., a biotechnology company. Mr. BarabeAselage earned a B.S. in biology from the University of Notre Dame. Mr. Aselage currently serves on the Advisory Council for the Department of Science at the University of Notre Dame and also serves on the board of directors at BioCryst Pharmaceuticals, Inc. (Nasdaq: BCRX), a pharmaceutical company, since January 2019, and at Acuitas Therapeutics, Inc., a biotechnology company. We believe that Mr. Aselage is qualified to serve on our Board due to his extensive experience in the pharmaceuticals and biotechnology industry, which will enable him to contribute important insights to our Board on strategic leadership and drug commercialization matters.

Jason Amello has served as a director since the completion of the 2017 merger of Opexa and private Acer. Since September 2022, Mr. Amello has served as Chief Financial Officer of Regent Medical Limited,Candel Therapeutics, Inc. (Nasdaq: CADL), a U.K.-based, privately owned, surgical supply company, from 2004biopharmaceutical company. From September 2020 to 2006. He was with Novartis AG from 1982 throughSeptember 2022, Mr. Amello served as Chief

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Financial Officer of Saniona AB, a rare disease biopharmaceutical company. From September 2013 to August 2004, where2020, he served in a succession of senior executive positions in finance and general management, most recently as theSenior Vice President, Chief Financial Officer and Treasurer of Sandoz GmbH,Akebia Therapeutics, Inc. (Nasdaq: AKBA), a biopharmaceutical company. From May 2012 to May 2013, Mr. Amello served as Executive Vice President, Chief Financial Officer and Treasurer of ZIOPHARM Oncology, Inc., a biopharmaceutical company. From April 2000 to June 2011, he held various positions at Genzyme Corporation, a then Nasdaq-listed biotechnology company, most recently, from December 2008 to June 2011, as Senior Vice President, Corporate Controller, and Chief Accounting Officer. Earlier in his career, Mr. Amello spent ten years in the generic pharmaceutical subsidiarybusiness advisory and assurance practice of Novartis. Mr. BarabeDeloitte Touche Tohmatsu Limited, serving in various roles of increasing responsibility through Senior Manager. He currently serves on the boards of: ArQule, Inc.,board of directors of the New England Baptist Hospital, an orthopedic specialty hospital. Mr. Amello earned a Boston-based, NASDAQ-listed biotech company; Vigilant Biosciences, Inc.,B.A. in accounting from Boston College and is a private medical device company; Veeva Systems Inc., a cloud based software company focusingCertified Public Accountant in the Commonwealth of Massachusetts. We believe that Mr. Amello is qualified to serve on the life sciences industry; and Project Open Hand, a non-profit organization. He receivedour Board due to his B.B.A. degree from the University of Massachusetts (Amherst) and his M.B.A. from the University of Chicago. Mr. Barabe has extensive experience as a senior financial executive ofin finance related to managing life sciences companies, givingwhich will enable him valuable operationalto contribute important insights to our Board on financial matters toward the continued growth and financial experience, including in the international setting, and knowledgeexpansion of both the pharmaceutical and biotech industries.Acer.

Hans-Peter Hartung, M.D.John M. Dunn has served as a Directordirector since March 2014the completion of the 2017 merger of Opexa and private Acer. From October 2015 until the merger, Mr. Dunn served as a member of our Scientific Advisoryprivate Acer’s Board since 2010. Heof Directors. Since April 2021, Mr. Dunn has served as General Counsel for CalciMedica Inc., a biotechnology company. From April 2019 to April 2021, he worked as a consultant in the life sciences industry. From November 2014 to April 2019, he served as General Counsel of Vital Therapies, Inc. (“Vital Therapies”), now Immunic, Inc. (Nasdaq: IMUX), a biotherapeutic company. Prior to joining Vital Therapies, Mr. Dunn was a consultant from February 2012 to November 2014, an Executive Vice President of Biogen Idec, Inc., now Biogen Inc. (”Biogen”) (Nasdaq: BIIB), a biotechnology company, from November 2003 to January 2012, where he was the head of that firm’s corporate venture group, and General Counsel of IDEC Pharmaceuticals from 2002 until its merger with Biogen in November 2003. Mr. Dunn has served as a professordirector of Sharp HealthCare, a nonprofit regional health care delivery system, since 2019. Mr. Dunn earned a B.S. in finance and Chairman of the Department of Neurology at Heinrich Heine University of Düsseldorf, Germany since 2001. Dr. Hartung earned his M.D. degreea J.D. from the University of DüsseldorfWyoming. We believe that Mr. Dunn is qualified to serve on our Board as a result of his deep experience relating to corporate governance and received post-graduate training in immunology, neurologyregulatory and neuroimmunology at the University of Mainz, Germany and the University of Düsseldorf. He is a member of several international and national medical societies, serves on various executive and academic boards, as well as on the editorial board of a number of international medical journals (including past-president of ECTRIMS, the European Neurological Society, the International Society for Neuroimmunology, the International Federation of Multiple Sclerosis Societies and the World Health Organization Advisory Board on Multiple Sclerosis). He has also been published extensivelyfinancing matters in the field of neuroimmunological disorders. Dr. Hartung has extensive experience in the field of drug discoverypharmaceuticals and development, is a leader in the field of clinical immunology and has broad leadership experience on various boards.biotechnology industry, which will enable him to contribute important strategic insights to our Board.

Gail J. MaderisMichelle Griffin has served as a Directordirector since the completion of the 2017 merger of Opexa and private Acer. Ms. Griffin serves as a member of the board of directors and as Chair of the audit committees for Chinook Therapeutics, Inc. (Nasdaq: KDNY), a biotechnology company, since October 2011.2020, Adaptive Biotechnologies Corporation (Nasdaq: ADPT), a biotechnology company, since March 2019. She has also served as a director for HTG Molecular Diagnostics, Inc. (Nasdaq: HTGM), a life sciences company since August 2018 and serves as a member of its audit and compensation committees. From 2013 to 2020, Ms. MaderisGriffin served as the Principal of Pacific Biotechnology Consulting Group, a firm providing consulting services to biotechnology companies and their boards of directors. Ms. Griffin previously served as a member of the board of directors and as Chair of the audit committee for then publicly traded companies PhaseRx, Inc., a biotechnology company, from 2016 until its acquisition by Roivant Sciences GmbH (Nasdaq: ROIV), a healthcare company, in 2018, OncoGenex Pharmaceuticals, Inc. (“OncoGenex Pharmaceuticals”), a biopharmaceutical company, from 2008 to 2011, and Sonus Pharmaceuticals, Inc., a biotechnology company, (subsequently acquired by OncoGenex) from 2004 to 2008. Ms. Griffin served from January 2011 to March 2013 as Executive Vice President, Operations and Chief Financial Officer of OncoGenex Pharmaceuticals. During various periods from 1997 to 2011, she served in the capacity of Chief Financial Officer for Trubion Pharmaceuticals, Inc., a biopharmaceutical company, Dendreon Corporation, a biotechnology company, and Corixa Corporation, a biotechnology and pharmaceutical company. Ms. Griffin earned a B.S. in marketing from George Mason University and an M.B.A. with a specialization in finance and international business from Seattle University. We believe that Ms. Griffin is qualified to serve on our Board as a result of her extensive operational experience in the biotechnology industry and deep experience in public company financial matters, which will enable her to contribute important insights to our Board on drug development and financial matters.

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Chris Schelling has served as thea director and as our President and Chief Executive Officer since the completion of Antiva Biosciences,the 2017 merger of Opexa and private Acer. Mr. Schelling founded private Acer Therapeutics Inc. since July 2015. Formerly, Ms. Maderisin December 2013 and served as a director from that time until the 2017 merger. From December 2013 to February 2016, he served as private Acer’s Chief Operating Officer, and from February 2016 until the merger, he served as private Acer’s President and CEO of BayBio (Bay Area Bioscience Association), an independent, non-profit trade association serving the life sciences industry in Northern California, from October 2009Chief Executive Officer. Prior to March 2015, and also served on BayBio’s board from 2004 to March 2015. From July 2003 to June 2009, Ms. Maderisfounding private Acer, he served as President and CEOExecutive Director of Five Prime Therapeutics,Strategic Marketing at BioMarin from May 2006 to October 2012. Mr. Schelling also founded Censa Pharmaceuticals Inc. (“Censa”), a biotechnologybiopharmaceutical company, focused on the discovery and development of innovative protein and antibody drugs,in 2015 and served as a director until 2010. Prior to that, Ms. Maderis held general management positions at Genzyme Corporation from 1997 to 2003, including founder and president of Genzyme Molecular Oncology, a publicly traded division of Genzyme, and corporate vice president of Genzyme Corporation. Ms. Maderis has served as a director of NovaBay Pharmaceuticals, Inc. since October 2010. Ms. Maderis has also been a member of several private company boards. Ms. Maderis received a B.S. degree in business from the University of California at Berkeley and an M.B.A. from Harvard Business School. Ms. Maderis has extensive experience as a senior executive of life sciences companies, giving her valuable operational and industry experience and leadership skills, as well as an extensive network of contacts related to financing, partnering and support services in the biotech industry and visibility into business and policy trends that impact the biopharmaceutical industry.

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Michael S. Richmanhas served as a Director since June 2006. Mr. Richman has served as President and Chief Executive Officer of NextCure, Inc. since December 2015. Mr. Richman served as president and chief executive officer of Amplimmune, Inc. from July 2008 to July 2015. Mr. Richman served as president and chief operating officer of Amplimmune, Inc. from May 2007 to July 2008. From April 2002 to May 2007, Mr. Richman served as executive vice president and chief operating officer of MacroGenics, Inc. Mr. Richman joined MacroGenics, Inc. in 2002 with approximately 20 years’ experience in corporate business development within the biotechnology industry. Mr. Richman served as a director of Cougar Biotechnology from June 2006 to July 2009. Mr. Richman obtained his B.S. in Genetics/Molecular Biology at the University of California at Davis and his MSBA in International Business at San Francisco State University. He has extensive experience in business development and strategic planning for life science companies, as well as executive leadership and management experience.

Scott B. Seaman has served as a Director since April 2006. Mr. Seaman has served for over five years as (i) the executive director and treasurer of the Albert and Margaret Alkek Foundation of Houston, Texas, a private foundation primarily supporting biomedical research and institutions in the Texas Medical Center in Houston, Texas, (ii) the chief financial officer of Chaswil Ltd., a private family management company, (iii) secretary and treasurer of M & A Propertiesacquisition by PTC Therapeutics Inc., a ranching and real estate concern, (iv) managing member of ICT Development LLC, which is the managing member of ICT Holdings LLC, an energy services supplier, for which he serves as president, and (v) director of Somebody Cares America. In March 2013, Mr. Seaman was elected a director of Gradalis, Inc., a privately held clinical stage biotechnologybiopharmaceutical company, developing cancer focused immunotherapies. In June 2013, Mr. Seaman became a director of Strike Bio, Inc., a privately held clinical stage biotechnology company developing gene interference therapeutics. Mr. Seaman received a bachelor’s degree in business administration from Bowling Green State University and is a certified public accountant. Mr. Seaman has extensive experience in overall financial management and corporate development, combined with operational and corporate governance experience.

Neil K. Warma has served as President and Chief Executive Officer since June 2008 and as a Director since September 2008.May 2020. He has also served as Acting Chief Financial Officer since March 2016, and previously served as our Acting Chief Financial Officer from March 2009 to August 2012. From July 2004 to September 2007, Mr. Warma served as president and chief executive officer of Viron Therapeuticsa director at Cascade Prodrug, Inc., a privately-held clinical stagedeveloper of chemotherapy technology, since June 2017. He has also held roles at Abgenix, Inc. (“Abgenix”), a biopharmaceutical company, Cell Therapeutics, Stanford Research Institute Consulting, a non-profit research institute, and Organon & Co. (NYSE: OGN), a pharmaceutical company. From 2000 to 2003 Mr. Warma was co-founderSchelling earned B.A. degrees in biology and presidenthistory from Carroll College. We believe that Mr. Schelling’s role in the founding of MedExact USA, Inc., an Internet company providing clinical information and services to physicians and pharmaceutical companies. From 1992 to 2000, Mr. Warma held senior positions of increasing responsibility at Novartis Pharmaceuticals (previously Ciba-Geigy Ltd.) at its corporate headquarters in Basel, Switzerland. While at Novartis, Mr. Warma servedAcer, his experience as the Head of International Pharma Policy & Advocacy and in senior management within global marketing where he worked on the international launch of a gastrointestinal product. Mr. Warma obtained an honors degree specializing in Neuroscience from the University of Toronto and an International M.B.A. from the Schulich School of Management at York University in Toronto. As our President andAcer’s Chief Executive Officer Mr. Warma is directly involved in all aspects of our operations. He has extensiveand his experience in corporate business development within the biopharmaceuticalbiotechnology industry in additionqualify him to executive leadership and management experience.serve on our Board.

The Board of Directors recommends a vote

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THE BOARD OF DIRECTORS RECOMMENDS A VOTE “FOR” the election of each the above nominees.THE ELECTION OF EACH OF THE DIRECTOR NOMINEES SET FORTH ABOVE

Board and ShareholderCommittee Meetings

Members of the Board are encouraged to attend ourthe Annual Meeting of shareholders;Meeting; however, we do not have a policy regarding director attendance is not mandatory. All six of ourat annual meetings. No directors attended the 2015 Annual Meeting of shareholders. For2022 annual meeting. During the fiscal year ended December 31, 2015,2022, the Board held tennine meetings, and each director attended at least 75% of the total number of meetings held by the Board and all committees on which such director served during the period he or she was a director in 2015, except for Dr. Hartung.director.

Director Independence

The Board has determined that Ms. Griffin and Messrs. Barabe, RichmanAmello, Aselage and Seaman, Dr. Hartung and Ms. MaderisDunn are each an independent director within the meaning of NASDAQNasdaq listing standards, which directors constitute a majority of the Board. The Board has determined that each member of the Board’s Audit, Compensation and Nominating and Corporate Governance Committees is independent (or similarly designated) based on the Board’s application of the standards of NASDAQNasdaq and the rules and regulations promulgated by the SEC or the Internal Revenue Service, as appropriate for such committee membership.

Committees of the Board of Directors

We currently have a standing Audit Committee, Compensation Committee, and Nominating and Corporate Governance Committee. The Board has adopted written charters for each of the committees, and copies of the charters are available on our website at www.opexatherapeutics.com.www.acertx.com. Please note that the information contained on our website is not incorporated by reference in, or considered to be a part of, this document.Proxy Statement.

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The current members of these committees are as follows:

C = Chair

Audit Committee

The Audit Committee of the Board currently consists of Messrs. SeamanAmello (chair) and BarabeDunn and Ms. Maderis,Griffin, each of whom is an independent, non-employee director. The Audit Committee selects, on behalf of our Board, an independent public accounting firm to audit our financial statements, discusses with the independent auditorsregistered public accounting firm their independence, reviews and discusses the audited financial statements with the independent auditorsregistered public accounting firm and management, recommends to our Board whether the audited financials should be included in our annual reports to be filed with the SEC, and oversees management’s identification, evaluation, and mitigation of major risks to Opexa.the Company. The Audit Committee operates pursuant to a written charter. During the last fiscal year, the Audit Committee held foursix meetings.

All of the members of the Audit Committee are non-employee directors who: (1) met the criteria for independence as required by NASDAQNasdaq listing standards and as set forth in Rule 10A-3(b)(1) under the Securities Exchange Act of 1934, as amended (the “Exchange Act”);Act; (2) did not participate in preparation of our financial statements during the past three years; and (3) are able

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to read and understand fundamental financial statements, including a balance sheet, income statement, and cash flow statement. The Board has determined that Ms. Griffin and Messrs. SeamanAmello and Barabe and Ms. MaderisDunn each, individually, qualifyqualifies as an “audit committee financial expert” as defined in SEC rules and regulations and also possesses the financial sophistication and requisite experience as required under NASDAQNasdaq listing standards.

Compensation Committee

The Compensation Committee of the Board currently consists of Messrs. BarabeMs. Griffin (chair) and Richman and Ms. Maderis,Mr. Aselage, each of whom is an independent director. The Compensation Committee reviews and approves (1) the annual salaries and other compensation of our executive officers and (2) individual stock and stock option grants. The Compensation Committee also provides assistance and recommendations with respect to our compensation policies and practices, and assists with the administration of our compensation plans. In evaluating executive officer compensation, the Compensation Committee may retain the services of compensation consultants and considers recommendations from the Chief Executive Officer with respect to compensation of the other executive officers. TheFrom time to time and as it determines necessary or desirable, the Compensation Committee also periodically reviewsmay retain the services of an independent compensation for non-employeeconsultant to advise on compensation-related matters relating to the executive officers and independent directors. During the last fiscal year, the Compensation Committee held three meetings.one meeting. In addition, the Compensation Committee engaged in discussions without formally meeting, to build consensus on various matters, with formal action thereafter taken by the Board.

The Board has established a Special Equity Grant Committee, the members of which are our President and Chief Executive Officer, Chris Schelling, our Chief Financial Officer, Harry S. Palmin, and our Chief Legal Officer, Donald R. Joseph. The Special Equity Grant Committee has been delegated the authority to make first-time option grants under our 2018 Stock Incentive Plan to employees (including new employees), other than to any member of our Board or to an officer at or above the level of vice president (whether or not designated as a “Section 16 officer”), within a specified range and subject to an overall cap as established by our Board.

Nominating and Corporate Governance Committee

The Nominating and Corporate Governance Committee of the Board currently consists of Ms. MaderisMessrs. Dunn (chair) and Messrs. Richman and Seaman,Aselage, each of whom was determined by the Board to be an independent director. The Nominating and Corporate Governance Committee assists our Board in fulfilling its responsibilities by: identifying and approving individuals qualified to serve as members of our Board, selecting director nominees for our annual meetings of shareholders,stockholders, evaluating the performance of our Board, and developing and recommending to our Board corporate governance guidelines and oversight procedures with respect to corporate governance and ethical conduct. In identifying and evaluating candidates, the committeeNominating and Corporate Governance Committee takes into consideration the criteria approved by the Board and such other factors as it deems appropriate. We do not have a formal diversity policy, and the committeeNominating and Corporate Governance Committee considers a broad range of factors in evaluating prospective director nominees. These factors may include judgment, skill, diversity, experience with businesses and other organizations of comparable size, the interplay of the candidate’s experience with the experience of other Board members, and the extent to which the candidate would be a desirable addition to the Board and any committees of the Board. The Nominating and Corporate Governance Committee will consider properly submitted shareholderstockholder nominations for candidates for the Board. Following verification of the shareholderstockholder status of persons proposing candidates, recommendations will be aggregated and considered by the Nominating and Corporate Governance Committee. If any materials are provided by a shareholderstockholder in connection with the nomination of a director candidate, such materials will be forwarded to the Nominating and Corporate Governance Committee. During the last fiscal year, the Nominating and Corporate Governance Committee held two meetings.

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Risk Oversight

A fundamental part of risk management is not only understanding the risks a company faces and what steps management is taking to manage those risks, but also understanding what level of risk is appropriate for each company. Our Board is actively involved in oversight of risks that could affect Opexa.Acer. The full Board has retained the responsibility for general oversight of risks, but the Audit Committee primarily oversees those risks that may directly or indirectly impact our financial statements. The Board’s role in the risk oversight process includes receiving reports from members of management and the Audit Committee on areas of material risk to Opexa,Acer, including operational, financial, cybersecurity, legal and regulatory, and strategic risks which enable it to better understand our risk identification, management and mitigation strategies.

Board Leadership Structure

The Board evaluates its leadership structuredoes not have a policy on an ongoing basis according to whatwhether the same person should serve as both the chief executive officer and chairman of the Board considersor, if the roles are separate, whether the chair should be selected from the non-employee directors or should be an employee. The Board believes that it should have the flexibility to be best for Opexamake these determinations at any given point in time in the way that it believes best to provide appropriate leadership for the Company at that time. Because weHowever, the Board has committed to elect a lead independent director if the roles of chief executive officer and chair of the Board are held by the same individual at any time. The Board believes that its current leadership structure, with Mr. Aselage serving as a clinical stage company, we do not currently have a separate role fornon-employee Chairman of the Board. OurBoard and Mr. Schelling serving as Chief Executive Officer, is in consultationthe best interest of stockholders at this time. The current structure ensures a greater role for the independent directors in the oversight of the Company and active participation of the independent directors in setting agendas and establishing priorities and procedures for the work of the Board.

Code of Ethics

In accordance with SEC rules, the Audit Committee and the Board of Directors has adopted a Policy on Whistleblower Protection and Code of Ethics which is applicable to our principal executive officer, principal financial officer, principal accounting officer or controller, or persons performing similar functions, which we sometimes refer to as our senior financial officers. The Board of Directors believes that these individuals must set an exemplary standard of conduct, particularly in the areas of accounting, internal accounting control, auditing and finance. This Code of Ethics sets forth ethical standards to which the designated officers must adhere and other aspects of accounting, auditing and financial compliance. The Code of Ethics is available free of charge on our strategic direction,website at www.acertx.com. Please note that the information contained on our website is not incorporated by reference in, or considered to be a part of, this Proxy Statement.

Anti-Hedging Policy

Under our insider trading policy, our directors, officers, employees, consultants and he managescontractors are prohibited from engaging in short sales of our securities, purchases of our securities on margin, hedging or monetization transactions through the day to day leadershipuse of financial instruments, and performanceoptions and derivatives trading on any of Opexa. Giventhe stock exchanges or futures exchanges, without prior written pre-clearance from our current size Chief Legal Officer or our Chief Financial Officer.

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Board Diversity Matrix

The following matrix discloses the gender and stagedemographic backgrounds of development, theour Board believes this leadership structure is appropriate for Opexa.as self-identified by its members in accordance with Nasdaq Listing Rule 5606.

2015

2022 Director Compensation

The following table presents summary information regarding compensation of the non-employee members of our Board of Directors who served during any part of the fiscal year ended December 31, 2015.2022.

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Standard Compensation Arrangements

EmployeeIndependent directors doreceive compensation for their service on our Board that consists of cash compensation and equity awards as described below. A director who is also our employee does not receive any additional compensation for services as a member of our Board. We reimburse our directors for travel and lodging expenses in connection with their attendance at Board and committee meetings. Our standard annual compensation arrangements for our non-employee directors consistsconsist of the following, valued at $55,000:following:

Board Member Cash Compensation:

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Additional Committee Chair Cash Compensation:

Additional Committee Member Cash Compensation:

Board Member Equity Compensation:

Communications to the Board of Directors

The Board has adopted the following policy for shareholdersstockholders who wish to communicate any concern directly with the Board. ShareholdersStockholders may mail or deliver their communication to our principal executive offices, addressed as follows:

Addressee (*)

c/o Secretary

OpexaAcer Therapeutics Inc.

2635 Technology Forest Blvd.One Gateway Center, Suite 356

The Woodlands, TX 77381300 Washington Street

Newton, MA 02458

*Addressees: Board of Directors; Audit Committee of the Board of Directors; Nominating and Corporate Governance Committee of the Board of Directors; Compensation Committee of the Board of Directors; name of individual director.

Copies of written communications received at such address will be forwarded to the addressee as soon as practicable.

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AUDIT COMMITTEE REPORT

The Audit Committee of the Board of Directors currently consists of Ms. Griffin and Messrs. SeamanAmello and Barabe and Ms. Maderis,Dunn, all of whom are independent, non-employee directors.

The Audit Committee operates under a written charter adopted by the Board, which is evaluated annually. The Audit Committee selects, evaluates and, where deemed appropriate, replaces the Company’s independent auditors.registered public accounting firm. The Audit Committee also pre-approves all audit services, engagement fees and terms, and all permitted non-audit engagements, except for certain de minimis amounts.

Management is responsible for the Company’s internal controls and the financial reporting process. The Company’s independent auditorsregistered public accounting firm are responsible for performing an independent audit of Opexa’s consolidatedAcer’s financial statements in accordance with auditing standards generally accepted in the United States of America and issuing a report on Opexa’s consolidatedAcer’s financial statements. The Audit Committee’s responsibility is to monitor and oversee these processes.

In this context, the Audit Committee has reviewed the Company’s audited financial statements for fiscal 20152022 and has met and held discussions with management and MaloneBailey,BDO USA, LLP, the Company’s independent auditors.registered public accounting firm for fiscal 2022. Management represented to the Audit Committee that the Company’s consolidated financial statements for fiscal 20152022 were prepared in accordance with accounting principles generally accepted in the United States of America, and the Audit Committee discussed the consolidated financial statements with the independent auditors.registered public accounting firm. The Audit Committee also discussed with MaloneBailey,BDO USA, LLP the matters required to be discussed by Auditing Standard No. 16, Communications with Audit Committees, as adopted byapplicable standards of the Public Company Accounting Oversight Board (PCAOB). and the SEC.

MaloneBailey,BDO USA, LLP also provided to the Audit Committee the written disclosures and the letter required by applicable requirements of the PCAOB regarding the independent auditors’registered public accounting firm’s communications with the Audit Committee concerning independence, and the Audit Committee discussed with MaloneBailey,BDO USA, LLP the accounting firm’s independence.

Based upon the Audit Committee’s discussion with management and MaloneBailey,BDO USA, LLP, and the Audit Committee’s review of the representation of management and the report of MaloneBailey,BDO USA, LLP to the Audit Committee, the Audit Committee recommended to the Board of Directors that the audited consolidated financial statements be included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 20152022 filed with the SEC.

Submitted by the Audit Committee of the

Board of Directors of OpexaAcer Therapeutics Inc.:

Scott B. Seaman,Jason Amello, Chair

Timothy C. BarabeJohn M. Dunn

Gail J. Maderis

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PROPOSAL 2

APPROVAL OF AMENDED AND RESTATED 2010 STOCK INCENTIVE PLAN

We are asking our shareholders to approve our Amended and Restated 2010 Stock Incentive Plan (the “2010 Plan”) in accordance with Nasdaq listing standards, which generally require shareholder approval of all material revisions to equity compensation plans, and also for purposes of Section 162(m) of the Internal Revenue Code. On March 29, 2016 our Board amended and restated the 2010 Plan, subject to shareholder approval, in order to (i) increase the number of shares of common stock reserved for issuance by an additional 650,000 shares and (ii) reset the number of stock-based awards issuable to a participant in any calendar year. As of December 31, 2015, options to purchase 379,306 shares were outstanding under the 2010 Plan, 60,810 shares remained available for future issuance under the 2010 Plan, and options to purchase 38,098 shares were outstanding under the Company’s 2004 Compensatory Stock Option Plan (“2004 Plan”). All share amounts set forth in this proxy statement reflect the 1-for-4 reverse split of our common stock effected on December 14, 2012 and the 1-for-8 reverse split of our common stock effected on September 28, 2015.

In order for certain compensation to be considered performance-based, and therefore deductible under Section 162(m) of the Internal Revenue Code, material terms of the potential performance goals/ measures applicable to that compensation must be approved by shareholders at least every five years. For purposes of Section 162(m) of the Internal Revenue Code, the material terms of the performance goals that we are asking you to approve consist of: (i) the individuals eligible to receive compensation, (ii) a description of the business criteria/performance measures on which the performance goals are based, and (iii) the maximum amount of compensation that could be paid to any individual. Approval of this Proposal 2 will constitute approval of the material terms of the performance criteria, as summarized below.

The Board initially adopted the Opexa Therapeutics, Inc. 2010 Stock Incentive Plan on September 2, 2010 for the granting of equity incentive awards to employees, directors and consultants of Opexa, and the Plan was initially approved by our shareholders on October 19, 2010. On September 25, 2013, the Board amended and restated the 2010 Plan and it was approved by our shareholders on November 8, 2013, in order to (i) increase the number of shares of common stock reserved for issuance by 375,000 shares and (ii) reset the number of stock-based awards issuable to a participant in any calendar year.

Why You Should Vote for Approval of our Amended and Restated 2010 Stock Incentive Plan

Stock Options Are an Important Part of Our Compensation Philosophy

The 2010 Plan is critical to our ongoing effort to build shareholder value. As discussed in the section entitled “Compensation Overview,” equity incentive awards are central to our compensation program. Our Compensation Committee and Board believe that our ability to grant stock options to new and existing employees has helped us attract, retain and motivate key talent. Since the potential value of stock options is realized only if our share price increases, this form of compensation provides a strong incentive for employees to work to grow the business and build shareholder value, and is most attractive to employees who share the entrepreneurial spirit that we believe is key to making our company a success. The Board of Directors believes the number of shares remaining available for future issuance under the 2010 Plan prior to its amendment is inadequate to achieve the purpose of the 2010 Plan in the future.

The Number of Shares Proposed for the Increase is Reasonable

When our shareholders originally approved the 2010 Plan, a total reserve of 78,125 shares was established, plus an additional number of shares subject to stock options outstanding under our predecessor 2004 Plan at the time the 2010 Plan was originally adopted in 2010 that are forfeited or terminate prior to exercise and would otherwise be returned to the share reserve under the 2004 Plan, and any reserved shares not issued or subject to outstanding grants at the time the 2010 Plan was originally adopted in 2010, up to a maximum of 64,152 shares. The 2010 Plan was amended on September 25, 2013 to add an additional 375,000 shares. As of December 31, 2015, an additional 24,643 shares had been added to the 2010 Plan from the 2004 Plan as a result of the rollover provision. Our 2010 Plan is currently our only equity compensation plan under which we may make equity awards.

At the time we originally adopted the 2010 Plan, we anticipated that the original share reserve would be sufficient for at least three years’ worth of equity grants. In 2013, we returned to shareholders to obtain approval to add additional shares that we believed would be sufficient for at least an additional three years’ worth of equity grants.

We believe our granting practices have been maintained at a reasonable level, and we do not believe the proposed 650,000 share increase will be unduly dilutive to stockholders:

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As previously disclosed, on March 2, 2016, we announced implementation of a restructuring initiative which included a reduction of approximately 30% of our then full-time workforce of 36 employees in order to reduce operating expenses and conserve cash resources. The restructuring initiative was driven by reduced operational demands associated with the Phase 2b “Abili-T” clinical trial for Tcelna in patients with secondary progressive multiple sclerosis (SPMS) following administration of the final dose to the last patient in such trial, which occurred in the last week of February 2016. It is intended to allow us to focus our resources on completion of the Abili-T clinical trial, for which top-line data is expected early in the fourth quarter of 2016.

Because we expect significant clinical data to be available later this year, we believe that forecasting our equity award needs for the coming 12-month period is appropriate at this time, rather than a longer period of several years. As of December 31, 2015, 60,810 shares remained available for the grant of new equity awards under the 2010 Plan, and a total of 6,982,909 shares of our common stock were outstanding. We believe such share reserve for the 2010 Plan as of December 31, 2015, i.e., less than 1% of the common stock outstanding and approximately 0.5% of our fully-diluted common shares as of the Record Date (assuming the exercise of all outstanding options and warrants), will not allow us to issue equity awards to our employees, consultants, executive officers and directors in 2016 that represent appropriate and meaningful incentives unless our shareholders approve this proposal to increase the number of shares reserved for issuance under our 2010 Plan. We believe that the total of 650,000 shares proposed for addition to the 2010 Plan reserve will be sufficient for at least one year of equity award grants under our current compensation program. We thus anticipate returning to shareholders in 2017 for approval of additional shares to be added to the 2010 Plan reserve, unless circumstances merit other action.

At the time the 2010 Plan was last amended in 2013, the maximum number of stock-based awards issuable to a participant in any one calendar year was limited to 150,000, which represented 40% of the total 375,000 shares added to the pool in 2013. In tandem with refreshing the share reserve available for future awards to add 650,000 shares to the pool, an increase is being made to the maximum number of stock-based awards issuable to a participant in any one calendar year. Upon approval of the 2010 Plan by our shareholders pursuant to this proposal 2, the individual participant limit will be reset from 150,000 to 300,000 shares.

The 2010 Plan Continues to Combine Compensation and Governance Best Practices

We included provisions in the 2010 Plan when it was originally adopted that are designed to protect our shareholders’ interests and to reflect corporate governance best practices including:

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Description of the Amended and Restated 2010 Stock Incentive Plan

The material features of the 2010 Plan are outlined below. This summary is qualified in its entirety by reference to the complete text of the 2010 Plan. Shareholders are urged to read the actual text of the 2010 Plan in its entirety, which is filed with this Proxy Statement as Appendix A and is available at http://www.sec.gov.

Background and Purpose

The terms of the 2010 Plan provide for the grant of stock options, restricted stock, stock appreciation rights, restricted stock units and performance awards that may be settled in cash, stock or other property.

The purpose of the 2010 Plan is to provide a means by which employees, directors, and consultants may be given an opportunity to purchase our common stock to assist us in securing and retaining the services of such persons, to secure and retain the services of persons capable of filling such positions, and to provide incentives for such persons to exert maximum efforts for our success.

Shares Available for Awards

If this proposal 2 is approved, the total number of shares of our common stock reserved for issuance under the 2010 Plan (the “Share Reserve”), will consist of:

As of December 31, 2015, options to purchase 379,306 shares were outstanding under the 2010 Plan, 60,810 shares remained available for future issuance under the 2010 Plan, and 37,652 shares of common stock had been issued pursuant to restricted stock awards thereunder. As of such date, options to purchase 38,098 shares were outstanding under our 2004 Plan. Stock options and restricted stock awards are the only types of awards that have been issued under the 2010 Plan. The weighted average exercise price of all options outstanding under both the 2004 Plan and the 2010 Plan is $18.04 per share, and the weighted average remaining term of such options is approximately 7.7 years as of December 31, 2015. A total of 6,982,909 shares of our common stock were outstanding as of December 31, 2015.

Shares subject to awards granted under the 2010 Plan that are forfeited or terminate before being exercised or settled, or are not delivered to the participant because such award is settled in cash, will again become available for issuance under the 2010 Plan. Shares withheld to satisfy the grant, exercise price or tax withholding obligation related to an award will again become available for issuance under the 2010 Plan. However, shares that have actually been issued will not again become available unless forfeited. If any shares of common stock issued pursuant to a stock award are forfeited back to us because of the failure to meet a contingency or condition required to vest such shares in the participant, then the shares which are forfeited will revert to and again become available for issuance under the 2010 Plan. No more than 1,167,277 shares may be delivered upon the exercise of incentive stock options granted under the 2010 Plan plus, to the extent allowable under applicable law, any shares that again become available for issuance under the 2010 Plan.

If this proposal 2 is approved, no participant in the 2010 Plan can receive option grants, restricted shares, stock appreciation rights or stock units totaling more than an aggregate of 300,000 shares in any calendar year, except in the participant’s first year of employment in which the participant may receive equity awards totaling up to 600,000 shares. No participant in the 2010 Plan may be paid more than an aggregate of $2.5 million in cash during any calendar year with respect to equity awards that are payable in cash.

Eligibility

Incentive stock options may be granted under the 2010 Plan only to our employees (including executive officers) and employees of our parent or subsidiary. Our employees (including executive officers), consultants and directors, and the employees (including executive officers) and consultants of our affiliates are eligible to receive all other types of awards under the 2010 Plan. All of our 26 employees as of March 10, 2016 (including officers), as well as our directors and consultants, are eligible to participate in the 2010 Plan.

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Administration

The 2010 Plan is administered by our Board, which may in turn delegate authority to administer the plan to a committee such as our Compensation Committee. Subject to the terms of the 2010 Plan, our Board (or, as applicable, our Compensation Committee) will determine recipients, the numbers and types of stock awards to be granted and the terms and conditions of the stock awards, including the period of their exercisability and vesting. Subject to the limitations set forth below, our Board (or, as applicable, our Compensation Committee) will also determine the exercise price of options granted under the 2010 Plan.

Repricing

The 2010 Plan expressly provides that, without the approval of the shareholders, the Board or Compensation Committee shall not have the authority to reduce the exercise price of any outstanding stock options or stock appreciation rights under the plan (except in connection with certain corporate transactions, such as stock splits, certain dividends, recapitalizations, reorganizations, mergers, spin-offs and the like), or cancel any outstanding underwater stock options or stock appreciation rights in exchange for cash or new stock awards under the 2010 Plan.

Stock Options

Stock options will be granted pursuant to stock option agreements. The exercise price for an option cannot be less than 100% of the fair market value of the common stock subject to the option on the date of grant. Options granted under the 2010 Plan will vest at the rate specified in the option agreement. Incentive stock options granted to any holder of more than 10% of the voting shares of our company must have an exercise price of at least 110% of the fair market value of our common stock on the date of grant.

The term of stock options granted under the 2010 Plan may not exceed ten years (five years in the case of an incentive stock option granted to any holder of more than 10% of our voting shares). Each stock option agreement will set forth any limitations on the right of the option holder to exercise the stock option following termination of service with us or any affiliate of ours.

Acceptable forms of consideration for the purchase of our common stock issued under the 2010 Plan will be determined by our Board (or, as applicable, our Compensation Committee) and may include cash, common stock previously owned by the option holder, payment through a broker assisted cashless exercise, or other legal consideration approved by our Board (or, as applicable, our Compensation Committee).

Generally, an option holder may not transfer a stock option other than by will or the laws of descent and distribution, unless otherwise permitted under the terms of the applicable stock option agreement.

ISO Limitations

The aggregate fair market value, determined at the time of grant, of shares of our common stock with respect to which incentive stock options (“ISOs”) may be exercisable for the first time by an optionholder during any calendar year under all of our stock plans may not exceed $100,000. The options or portions of options that exceed this limit are treated as nonstatutory stock options (“NSOs”). The aggregate maximum number of shares of common stock that may be issued pursuant to the exercise of ISOs shall be no more than 1,167,277 shares plus, to the extent allowable under applicable law, any shares that again become available for issuance under the 2010 Plan. No ISO may be granted 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.

Restricted Stock Awards

Restricted stock awards will be granted pursuant to restricted stock award agreements. A restricted stock award may be granted in consideration for the recipient’s services performed for us or an affiliate of ours. 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 our Board (or, as applicable, our Compensation Committee). 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.

Stock Appreciation Rights

Stock appreciation rights typically will provide for payments to the recipient based upon increases in the price of our common stock over the exercise price of the stock appreciation right. The exercise price of a stock appreciation right will be determined by our Board (or, as applicable, our Compensation Committee), which shall not be less than the fair market value of our common stock on the date of grant. Our Board (or, as applicable, our Compensation Committee) may elect to pay stock appreciation rights in cash or in common stock or in a combination of cash and common stock.

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Restricted Stock Unit Awards

Restricted stock unit awards will be granted pursuant to restricted stock unit award agreements. We will settle a restricted stock unit award by delivery of shares of our common stock, by cash, or by a combination of cash and stock as deemed appropriate by our Board (or, as applicable, our Compensation Committee) and set forth 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 our Board (or, as applicable, our Compensation Committee). 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.

Performance Awards

The 2010 Plan provides that Awards may be granted, issued, vested or retained based upon the attainment during a certain period of time of certain 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 generally be determined by our Board (or, as applicable, our Compensation Committee).

Performance goals under the 2010 Plan shall be determined by our Board (or, as applicable, our Compensation Committee), based on or related to one or more of the following performance criteria:

Changes to Capital Structure

In the event that there is a specified type of change in our capital structure, such as a stock split or stock dividend, the class and number of shares reserved under the 2010 Plan (including share limits) and the class and number of shares and exercise price or strike price, if applicable, of all outstanding stock awards will be appropriately and equitably adjusted.

Corporate Transactions

In the event of certain corporate transactions, all outstanding stock awards under the 2010 Plan may be assumed, continued or substituted for by any surviving entity. If the surviving entity elects not to assume, continue or substitute for such awards, the vesting or exercisability of such stock awards may be accelerated in full and then terminated, if and to the extent not exercised at or prior to the effective time of the corporate transaction, or we may terminate the stock awards upon payment of their intrinsic value in cash or cash equivalents.

Plan Amendments

Our Board will have the authority to amend or terminate the 2010 Plan. However, in general, no amendment or termination of the plan may materially impair any rights under awards already granted to a participant unless agreed to by the affected participant. We will obtain shareholder approval of any amendment to the 2010 Plan if required by applicable law.

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Plan Termination

Unless sooner terminated by the Board, the 2010 Plan will automatically terminate on September 1, 2020, the day before the tenth anniversary of the date the 2010 Plan was originally adopted by the Board.

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 2010 Plan is not qualified under the provisions of Section 401(a) of the Internal Revenue Code (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.

Nonstatutory Stock Options

Generally, there is no taxation upon the grant of an NSO where the option is granted with an exercise price equal to the fair market value of the underlying stock on the grant date. On exercise, an optionee 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 optionee is employed by us or one of our affiliates, that income will be subject to withholding tax. The optionee’s tax basis in those shares will be equal to their fair market value on the date of exercise of the option, and the optionee’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 optionee.

Incentive Stock Options

The 2010 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 optionee generally is not subject to ordinary income tax upon the grant or exercise of an ISO. If the optionee holds a share received on exercise of an ISO for more than two years from the date the option was granted and more than one year from the date the 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 optionee 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 optionee 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 option, the amount of ordinary income recognized by the optionee 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 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 option generally will be an adjustment included in the optionee’s alternative minimum taxable income for the year in which the option is exercised. 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 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 optionee, 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 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

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PROPOSAL 3

ADVISORY VOTE ON THE COMPENSATION OF OUR NAMED EXECUTIVE OFFICERS

Section 14A of the Exchange Act, in conjunction with the Dodd-Frank Wall Street Reform and Consumer Protection Act of 2010 (the “Dodd-Frank Act”), requires companies that are subject to the SEC’s proxy rules and regulations to hold a shareholder vote to approve, on an advisory (non-binding) basis, the compensation of their Named Executive Officers as disclosed in their proxy statements in accordance with the SEC’s rules. This proposal, commonly known as a “say-on-pay” proposal, gives you, as a shareholder, the opportunity to endorse or not endorse our fiscal 2015 executive compensation programs and policies and the compensation paid to our Named Executive Officers for the fiscal year ended December 31, 2015.

As described under the heading “Compensation Overview,” our executive compensation programs are designed to attract, motivate, and retain our Named Executive Officers, who are critical to our success. Under these programs, our Named Executive Officers are rewarded for the achievement of annual, long-term and strategic goals, and corporate goals. The Compensation Committee, which is comprised of independent directors, continually reviews the compensation programs for our Named Executive Officers to ensure they achieve the desired goals of aligning our executive compensation structure with our shareholders’ interests and current market practices.

This vote is not intended to address any specific item of compensation, but rather the overall compensation of our Named Executive Officers and the philosophy, policies and practices described in this Proxy Statement. Accordingly, we will ask our shareholders to vote “FOR” the following resolution at the 2016 Annual Meeting:

“RESOLVED, that the Company’s shareholders approve, on an advisory basis, the compensation of the Named Executive Officers, as disclosed in the Company’s Proxy Statement for the 2016 Annual Meeting of Shareholders pursuant to the compensation disclosure rules of the Securities and Exchange Commission.”

The say-on-pay vote is advisory, and therefore not binding on the Company, the Compensation Committee or our Board of Directors. Our Board of Directors and our Compensation Committee value the opinions of our shareholders and to the extent there is any significant vote against the Named Executive Officers’ compensation as disclosed in this Proxy Statement, we will consider our shareholders’ concerns and the Compensation Committee will evaluate whether any actions are necessary to address those concerns.

The Board of Directors recommends a vote “FOR” the approval of the compensation of our Named Executive Officers.

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PROPOSAL 42

RATIFICATION OF INDEPENDENT AUDITORSREGISTERED PUBLIC ACCOUNTING FIRM

The Audit Committee has selected MaloneBailey,BDO USA, LLP (“BDO”) as an independent registered public accounting firm to audit our financial statements for the year ending December 31, 20162023, and requestsour Board has directed that the shareholders ratify such selection. In the event the shareholders fail to ratify the appointment, the Audit Committee of the Board will consider it as a direction to select other auditors for the subsequent year. Even ifmanagement submit the selection is ratified, the Board at its discretion may direct the appointment of a differentour independent registered public accounting firm for ratification by our stockholders at any time during the subsequent year if the Board determines that such a change would be in the best interests of Opexa and our shareholders.

We are asking shareholders to ratify the selection of MaloneBailey, LLPAnnual Meeting. BDO has served as our independent auditorsregistered public accounting firm since March 7, 2019 and audited our financial statements for the fiscal year endingyears ended December 31, 2016. 2019, 2020, 2021, and 2022.

A representative of MaloneBailey, LLPBDO is expected to be present at the Annual Meeting, will have an opportunity to make a statement if the representative desires but is not expected to do so, and is expected to be available to respond to appropriate questions.

Neither our bylaws nor other governing documents or law require stockholder ratification of the selection of BDO as our independent registered public accounting firm. However, we are submitting the selection of BDO to the stockholders for ratification as a matter of good corporate practice. If our stockholders fail to ratify the selection, our Audit Committee will reconsider whether to retain that firm. Even if the selection is ratified, our Audit Committee in its discretion may direct the appointment of 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 our stockholders.

Principal Accountant Fees and Services

The following table presents the estimated aggregate fees billed to us for the fiscal years ended December 31, 2022 and 2021 by MaloneBailey, LLP for services performed during our last two fiscal years.BDO.

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Policy on Audit Committee Pre-Approval and Permissible Non-Audit Services of Independent AuditorsRegistered Public Accounting Firm

The Board’s policy is to pre-approve all audit and permissible non-audit services provided by the independent auditors.registered public accounting firm. These services may include audit services, audit-related services, tax services and other services. Pre-approval is generally provided for up to one year and any pre-approval is detailed as to the particular service or category of services and is generally subject to a specific budget. The independent auditorsregistered public accounting firm and management are required to periodically report to the Board regarding the extent of services provided by the independent auditorsregistered public accounting firm in accordance with this pre-approval, and the fees for the services performed to date. The Board may also pre-approve particular services on a case-by-case basis. TheWhile the Audit Committee pre-approvedCommittee’s practice is to pre-approve 100% of theany audit-related services, tax services, andor other services provided by our independent auditorsregistered public accounting firm, there were no such services rendered during the last two fiscal years.

The Board of Directors recommends a voteTHE BOARD OF DIRECTORS RECOMMENDS A VOTE “FOR” the ratification of the selection of MaloneBailey,THE RATIFICATION OF

THE SELECTION OF BDO USA, LLP as our independent auditors for the fiscal year ending December 31, 2016.

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EXECUTIVE OFFICERS

OurThe names of our executive officers are elected by the Boardand their ages as of Directors and serve at the discretion of the Board. Our current executive officersApril 14, 2023 are as follows:

Biographical information for our executive officers is set forth below:

Chris SchellingNeil K. Warma has served as President and Chief Executive Officer since June 2008 and as a Director since September 2008. He has also served as Acting Chief Financial Officer since March 2016, and previously served as our Acting Chief Financial Officer from March 2009. Refer to August 2012. From July 2004 to September 2007,“Director Nominees” section above for Mr. Warma served as president and chief executive officer of Viron Therapeutics Inc., a privately-held clinical stage biopharmaceutical company. From 2000 to 2003 Mr. Warma was co-founder and president of MedExact USA, Inc., an Internet company providing clinical information and services to physicians and pharmaceutical companies. From 1992 to 2000, Mr. Warma held senior positions of increasing responsibility at Novartis Pharmaceuticals (previously Ciba-Geigy Ltd.) at its corporate headquarters in Basel, Switzerland. While at Novartis, Mr. Warma served as the Head of International Pharma Policy & Advocacy and in senior management within global marketing where he worked on the international launch of a gastrointestinal product. Mr. Warma obtained an honors degree specializing in Neuroscience from the University of Toronto and an International M.B.A. from the Schulich School of Management at York University in Toronto. As our President and Chief Executive Officer, Mr. Warma is directly involved in all aspects of our operations. He has extensive experience in corporate business development within the biopharmaceutical industry, in addition to executive leadership and management experience.Schelling’s biographical information.

Don Healey, Ph.D.,Jefferson E. Davishas served as our Chief Scientific Officer since April 2013. Dr. Healey has over 25 years of experience in cellular immunology and immune regulation in both academic and biotech environments. Prior to joining Opexa in April 2010, Dr. Healey was Director of Immunology for Argos Therapeutics from 2003 to 2010, and was responsible for the development of novel autologous dendritic cell therapies for the treatment of renal carcinoma and HIV. Dr. Healey was Group Leader for Immunotherapy for ML Laboratories, UK (formerly Cobra Biotherapeutics) from 2001 to 2003, where he developed autologous dendritic cell therapies for the treatment of Melanoma. Dr. Healey was a member of Council of the British Society for Immunology from 1996 to 1998. He is a former lecturer in immunology at the University of Leicester, UK, and held post-doctoral positions in the Department of Pathology, Cambridge University, UK, conducting studies on immunoregulation in animal models of autoimmunity, including Type I Diabetes and Multiple Sclerosis. Dr. Healey obtained his Ph.D. at the Hunterian Institute in London, UK, and BSc in the Department of Pathology, Bristol University, UK.

Donna R. Rill was appointed as our Chief DevelopmentBusiness Officer in April 2013 andFebruary 2021. He previously served as Senior Vice Presidentour head of Operationscorporate development from July 2020 to January 2021 and Quality Systems since January 2009. From November 2004 until January 2009, sheas Acting Chief Business Officer of private Acer and then public Acer from December 2013 to October 2018. He served as Vice President of Operations. FromCorporate Development for Censa from November 2019 until its acquisition by PTC Therapeutics Inc. (Nasdaq: PTCT), a pharmaceutical company, in May 2020, and as a consultant from May 2015 to November 2019. Mr. Davis was employed by Extera Partners, an advisory and new venture creation firm in the life science industry, from April 2011 to July 2020, having served as a Partner from October 2014. In addition, he held senior business and corporate development roles at Genzyme Corporation, a biotechnology company, from January 2006 to May 2011, Archemix, a biotechnology company, from December 2003 to January 2006, ImmunoGen, Inc., (Nasdaq: IMGN), a biotechnology company, from October 2001 to December 2003, GenVec, Inc., a biotechnology company, from March 1998 to November 2004,2001, and Eli Lilly and Company (NYSE: LLY), a pharmaceutical company, from March 1996 to February 1998. Mr. Davis earned a B.S. in biochemistry from North Carolina State University and an M.B.A. from Duke University.

Tanya Hayden was appointed as our Chief Operating Officer in June 2022. She previously served as our Vice President of Program and Strategic Alliance Management from June 2021 to June 2022. Prior to joining the Company, Ms. Hayden served as the Director of Operational Excellence at Lonza Group Ltd., a biotechnology research company, from April 2018 to June 2021, and as Director, Value Chain Management from November 2018 to May 2021. Prior to that, she served most recently as Vice President of Manufacturing at Bend Research Inc. – Capsugel, a pharmaceutical manufacturing company, from January 2014 to April 2018. Ms. Hayden received a B.S. degree in Chemistry from Gonzaga University.

Donald R. Joseph has served as our Chief Legal Officer and Secretary since April 2018. He previously served as an advisor and consultant to biopharmaceutical and global health organizations. He has over twenty years of biopharmaceutical industry experience, including senior management positions in global health non-profit organizations. Mr. Joseph served as Chief Legal Officer and Board Secretary of Humanigen, Inc. (“Humanigen”) (Nasdaq: HGEN) (previously known as KaloBios Pharmaceuticals, Inc.), a biopharmaceutical company, from June 2013 to November 2015. Prior to Humanigen, he was Chief Executive Officer of BIO Ventures for Global Health (“BVGH”), from February to November 2012 and Chief Operating Officer from April 2010 to January 2012. He is a former Chairman and Secretary and former member of the BVGH Board of Directors. He previously served as General Counsel, Corporate Secretary, and in other senior management roles at publicly held biopharmaceutical companies, including Abgenix from January 2005 to March 2006 and Renovis, Inc., a biopharmaceutical company, from May 2006 to December 2006. Mr. Joseph has served since August 2017 as lead independent director of quality systems and process developmentAchieve Life Sciences, Inc. (Nasdaq: ACHV), a pharmaceutical

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company. Before entering the life sciences industry, Mr. Joseph practiced business law for a number of years in major firms, including as an international partner at Opexa Pharmaceuticals, Inc. From November 1997 to April 2003, she was the director of translational research for the Center for CellBaker & Gene Therapy at Baylor College of Medicine. Ms. Rill has worked to design and qualify GMP Cell & Gene Therapy Laboratories, GMP Vector Production facilities, and Translational Research Labs at St. Jude Children’s Research Hospital, Texas Children’s Hospital, and Baylor College of Medicine. Ms. RillMcKenzie. He received her B.S. in Medical Technologyhis J.D. degree from the University of Tennessee, Memphis.Texas School of Law, with honors.

John M. Klopp has served as our Chief Technical Officer since September 2019. He previously served as our Vice President, Manufacturing from January 2018 to September 2019. Prior to joining Acer, Mr. Klopp served as Senior Director, Manufacturing Management for Ultragenyx Pharmaceutical Inc. (Nasdaq: RARE), a biopharmaceutical company, where he worked from March 2013 to January 2018. Mr. Klopp holds a B.S. degree in chemistry from Pennsylvania State University and an M.S. in chemistry from the University of California, Berkeley.

Harry S. Palmin has served as our Chief Financial Officer since the completion of the 2017 merger of Opexa and private Acer and was appointed to the additional position of Chief Operating Officer from September 2018 to June 2022. From December 2013 to February 2016, Mr. Palmin served as the President, Chief Executive Officer and a director of private Acer, and from February 2016 to September 2017 he served as private Acer’s acting Chief Financial Officer. Prior to joining private Acer, he served in a variety of roles at Novelos Therapeutics, Inc., a pharmaceutical company, including as President and director from 1998 to October 2013, Chief Executive Officer from January 2005 to October 2013 and acting Chief Financial Officer from 1998 to September 2005. He has also held roles at Lehman Brothers and Morgan Stanley. Mr. Palmin earned a B.A. in economics from Brandeis University and an M.A. in international economics and finance from the Brandeis University International Business School.

Bernie Paul was appointed as our Chief People Officer in January 2022. He previously served as our Vice President, Human Resources from May 2019 to January 2021. Prior to joining Acer, Mr. Paul served as an advisor and consultant to various corporations from December 2017 to May 2019. Mr. Paul served as Vice President of Human Resources at Clarisonic, Inc., a skin care device production company, (acquired by L’Oréal Inc.) from June 2011 to December 2017. Earlier in his career, he served as Vice President Human Resources at Trubion Pharmaceuticals, Inc., a biopharmaceutical company, (acquired by Emergent BioSolutions Inc. (NYSE: EBS)) from May 2006 to March 2011 and as Vice President of Human Resources at Corixa Corporation, a biotechnology company, (acquired by GSK plc (NYSE: GSK)) from March 1995 to February 2006. Mr. Paul earned a B.S. in Education from Montana State University at Billings and an M.S. in Education from the State University of New York at Buffalo.

Adrian Quartel was appointed as our Chief Medical Officer in February 2022. He previously oversaw all scientific and medical functions as Chief Medical Officer at Adamas Pharmaceuticals, Inc., a biotechnology company, from September 2020 to February 2022. From June 2017 to September 2020, he served as the Group Vice President, Global Medical Affairs at BioMarin. Prior to BioMarin, Dr. Quartel held senior medical leadership roles where he was responsible for clinical development, pharmacovigilance, and medical affairs at Astellas Pharma Inc. from January 2004 to September 2006, at Chiltern, a specialist contract research organization, from September 2006 to July 2007, and at ICON plc (Nasdaq: ICLR), a clinical research organization, from August 2001 to January 2004. Earlier in his career, Dr. Quartel worked as a clinical research fellow at UCLA Cedar Sinai and as a resident in cardio-thoracic surgery at Erasmus University Medical Center. Dr. Quartel received an M.D. from Erasmus University Medical School, Rotterdam, in the Netherlands, and a post graduate specialization in pharmaceutical medicine from the Faculty of Pharmaceutical Medicine in London. He is board certified by the General Medical Council (GMC) in pharmaceutical medicine in the United Kingdom.

2018

EXECUTIVE COMPENSATION AND OTHER INFORMATION

Compensation Overview

Objectives of Our Executive Compensation Program

The Compensation Committee of our Board administers our executive compensation program. The Compensation Committee is composed entirely of independent directors.

The general philosophy of our executive compensation program is to align executive compensation with Opexa’s business objectives and the long-term interests of our shareholders. To that end, the Compensation Committee believes executive compensation packages we provide to our executives, including the Named Executive Officers, should include both cash and stock-based compensation that reward performance as measured against established goals. In addition, we strive to provide compensation that is competitive with other biopharmaceutical and biotechnology companies and that will allow us to attract, motivate, and retain qualified executives with superior talent and abilities.

Our executive compensation is designed to reward achievement of our corporate goals. In 2015, our corporate goals included, but were not limited to: (i) advancing our phase 2b clinical trial of Tcelna in patients with SPMS; (ii) obtaining additional financing to support our operations, including our phase 2b clinical trial of Tcelna in patients with SPMS; (iii) continuing the expansion of our T-cell technology platform through preclinical development of OPX-212 in neuromyelitis optica; and (iv) various corporate governance objectives. We believe that the focus of our executives on the achievement of corporate goals allows us to reward our executives for their roles in creating value for our shareholders.

Compensation Committee Processes and Procedures

The Compensation Committee has the primary authority to determine our compensation philosophy and to establish compensation for our executive officers. The Compensation Committee oversees our compensation and benefit plans and policies; administers our stock option plan; reviews the compensation components provided to our officers, employees, and consultants; grants options to purchase common stock to our officers, employees, and consultants; and reviews and makes recommendations to the Board regarding all forms of compensation to be provided to the members of the Board.

The Compensation Committee generally sets the initial compensation of each executive. The Compensation Committee annually reviews and in some cases adjusts compensation for executives. Although the Chief Executive Officer provides recommendations to the Compensation Committee regarding the compensation of the other executive officers, the Compensation Committee has full authority over all compensation matters relating to executive officers.

In establishing compensation amounts for our executives and independent directors, the Compensation Committee seeks to provide compensation that is competitive in light of current market conditions and industry practices. Accordingly, the Compensation Committee annually reviews market data which is comprised of proxy-disclosed data from peer companies and information from nationally recognized published surveys for the biopharmaceutical industry, adjusted for size. The market data helps the Committee gain perspective on the compensation levels and practices at peer companies and assess the relative competitiveness of the compensation paid to our executives and independent directors. The market data thus guides the Compensation Committee in its efforts to set executive compensation at competitive levels for comparable roles in the marketplace. The Compensation Committee then takes into account other factors, such as the importance of each executive officer’s role to the Company, individual expertise, experience, and performance, retention concerns and relevant compensation trends in the marketplace, in making its final compensation determinations.

Role of Compensation Consultant

From time to time and as it determines necessary or desirable, the Compensation Committee may retain the services of an independent compensation consultant to advise on compensation-related matters relating to the executive officers and independent directors. The Compensation Committee did not engage a consultant for compensation-related matters in 2015.

Elements of Executive Compensation

Although the Compensation Committee has not adopted any formal guidelines for allocating total compensation between equity compensation and cash compensation, it strives to maintain a strong link between executive incentives and the creation of shareholder value. Therefore, we emphasize incentive compensation in the form of stock options rather than base salary.

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Executive compensation consists of the following elements:

Base Salary. Base salaries for our executives are generally established based on the scope of their responsibilities, taking into account what the Compensation Committee believes to be, based on its general business experience, competitive market compensation paid by other companies for similar positions and recognizing cost of living considerations. Prior to making its recommendations and determinations, the Compensation Committee reviews each executive’s:

The Compensation Committee does not use any particular indices or formulae to arrive at each executive’s recommended pay level. Evaluations of past performance are made on a strictly qualitative basis, and may include such factors as leadership performance, contribution to the officer group, overall performance, continuous improvements, and other appropriate measures. In making decisions as to the base salaries of our executive officers, the Compensation Committee does not engage in benchmarking by using specific compensation data about other companies as a reference point.

Annual Cash Incentive Bonus. As described below under “Executive Employment Agreements,” each of the employment agreements we have entered into with our Named Executive Officers provides the officer with the opportunity to earn a cash bonus up to a stated percentage of his or her base salary based upon objectives and milestones to be agreed upon annually by our Board and Chief Executive Officer. The Board retains discretion, however, to pay a portion of any such bonus in the form of equity (including grants of restricted stock).

Equity Awards. We also use long-term incentives in the form of stock options and restricted stock awards. Employees and executive officers generally receive stock option grants at the commencement of employment and periodically receive additional stock option grants or restricted stock awards, typically on an annual basis. We believe that stock options and restricted stock awards incentivize executive performance and are instrumental in aligning the long-term interests of our employees and executive officers with those of the shareholders because such individuals realize gains based on the value of the underlying shares and stock price increases. Equity awards also help to balance the overall executive compensation program, with base salary and cash bonuses providing short-term compensation and stock options and restricted stock awards rewarding executives for long-term increases in shareholder value.

Options and restricted stock awards are granted through our 2010 Stock Incentive Plan. The Compensation Committee reviews and approves equity awards to executive officers in amounts that are based upon a review and assessment of:

Periodic equity awards are made at the discretion of the Compensation Committee to eligible employees and, in appropriate circumstances, the Compensation Committee considers the recommendations of members of management, such as the Chief Executive Officer. In determining the amount of any equity award, the Compensation Committee gives subjective consideration to our Named Executive Officers’ contributions towards the achievement of our goals.

In 2015, each Named Executive Officer was granted stock options in the amount indicated in the table entitled “2015 Outstanding Equity Awards at Fiscal Year-End.” Stock options are granted with an exercise price equal to the fair market value of our common stock on the day of grant and recent option grants generally vest 25% after one year with the remaining 75% vesting quarterly over the next three years. The grant date fair value of these equity awards is computed in accordance with FASB ASC 718, and such grant date fair value is included in the total compensation of each of the Named Executive Officers. See Note 10 to our financial statements included in our Annual Report on Form 10-K for assumptions underlying the valuation of equity awards.

Pursuant to the terms of our 2010 Stock Incentive Plan, in 2015 the Compensation Committee recommended that a pool of shares of common stock be available at the discretion of the Chief Executive Officer to grant stock options to non-executive employees, and the Board approved such delegation of authority. The purpose of this delegation of authority is to enhance the flexibility of option administration and to facilitate the timely grant of options to non-management employees.

Severance Arrangements. As described below under “Executive Employment Agreements,” each of the employment agreements we have entered into with our Named Executive Officers provides the officer with certain severance protection arrangements in the event the officer’s employment is terminated by the Board without cause. In such event, the officer will receive a

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severance payment equal to a stated number of months of base salary, subject to certain conditions and the execution and delivery of a general release and waiver of claims in our favor. We believe the provisions of these severance arrangements are consistent with the principal objectives of our compensation programs, appropriate for the level of service provided by each executive, and provide an important “safety net” that allows each executive to focus on our business and pursue the course of action that is in the best interests of our shareholders by alleviating some potential concerns regarding their personal financial well-being in the event of a termination.

Section 162(m) Policy

Section 162(m) of the Code limits the tax deductibility by public companies of compensation in excess of $1 million paid to certain executive officers. These officers include any employee who, as of the close of the taxable year, is the principal executive officer, and any employee whose total compensation for the taxable year is required to be reported to shareholders under the Exchange Act by reason of such employee being among the three highest compensated officers for that taxable year, other than the principal executive officer or the principal financial officer. However, compensation which qualifies as “performance-based” is excluded from the $1 million limit if, among other requirements, the compensation is payable only upon attainment of pre-established, objective performance goals under a plan approved by the corporation’s shareholders.

It is our policy to qualify, to the extent reasonable, our executive officers’ compensation for deductibility under applicable tax law. However, we intend to retain the flexibility necessary to provide total cash compensation in line with competitive practice, our compensation philosophy and our best interests. Therefore, we may from time to time pay compensation to our executive officers that may not be deductible.

Executive Officer Compensation

The following table sets forth certain information concerning compensation earned by or paid to certain persons who we refer to as our “Named Executive Officers” or “NEOs” for services provided for the fiscal yearyears ended December 31, 2015. Our Named Executive Officers include persons who (i) served as our principal executive officer or acted in a similar capacity during 2015, (ii) were serving at fiscal year-end as our two most highly compensated executive officers, other than the principal executive officer, whose total compensation exceeded $100,000,2022 and (iii) if applicable, up to two additional individuals for whom disclosure would have been provided as a most highly compensated executive officer, but for the fact that the individual was not serving as an executive officer at fiscal year-end.2021.

20152022 Summary Compensation Table

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Executive Employment AgreementsNarrative Disclosure to Summary Compensation Table

Neil K. Warma.Our Board reviews compensation annually for all of the executive officers. Compensation awarded to Named Executive Officers in 2022 and 2021 generally consisted of base salary, discretionary cash bonuses and equity awards for options to purchase shares of our common stock. In setting executive compensation, our Board previously retained the services of Radford (which is a part of Aon Hewitt, a business unit of Aon plc) as an independent compensation consultant and considered compensation for comparable positions in the market, the historical compensation levels of the executives, individual performance as compared to its expectations and objectives, the desire to motivate employees to achieve short- and long-term results that are in the best interests of our stockholders, and a long-term commitment to our company. We do not target a specific competitive position or a specific mix of compensation among elements of compensation. In reviewing the reports prepared by Radford, our Compensation Committee considered the independence of Radford pursuant to SEC rules and the corporate governance rules of the Nasdaq Capital Market and concluded that no conflict of interest exists that would prevent Radford from independently advising the Compensation Committee.

On February 22, 2018, we entered into an employment agreement with each of Messrs. Schelling and Palmin, and on June 16, 2008February 21, 2022, we entered into an employment agreement with Neil K. Warma pursuant to which he servesDr. Quartel. The terms and conditions of such employment agreements are described below and are identical for each executive officer, other than in respect of each individual’s title, duties, salary and target bonus percentage as our President and Chief Executive Officer. set forth below.

Pursuant to theeach individual’s employment agreement, which automatically renews for 12-month periods, Mr. Warmaeach executive is currently compensated at thean annual base rate of $416,625 per annum. In addition, Mr. Warmaand is entitledeligible to the following: (i)receive an annual discretionary cash bonus of up to 50%a target bonus percentage of his base salary (i.e., 55% for Mr. Schelling and 40% for each of the other executive officers) per 12-month period, based upon milestones

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the achievement of corporate objectives established from time to be agreed upon;time by our Board, and (ii) a one-time payment of $50,000 cashsubject to review and 781shares of our common stockadjustment from time to be issued if and whentime as determined by the closing bid price of our common stock equals or exceeds $128.00 for 20 consecutive trading days.Board. In addition, we provide Mr. Warma witheach executive receives our standard benefits and insurance coverage as generally provided to our management, as well as contractual indemnification rights by reason of his serviceemployees. Each executive’s employment is at-will and he serves as an executive officer and employee. If hisat the discretion of our Board.

In the event the executive’s employment is terminated by the Boardus without cause, asCause (as defined in the agreement, Mr. Warmaagreement) or due to a Constructive Termination (as defined in the agreement), in each instance during the period commencing one month prior to a Change in Control (as defined in the agreement) and terminating 12 months after such Change in Control, the executive will be entitled to (i) a payment, less applicable taxes and withholdings, equal to his then-current base salary for a period of 12 months plus (ii) 1x times his annual discretionary target bonus calculated for such period. In the event the executive’s employment is terminated by us without Cause or due to a Constructive Termination occurring outside of a Change in Control Period (as defined in the agreement), the executive will be entitled to a payment, less applicable taxes and withholdings, equal to his then-current base salary for a period of 12 months. The executive would receive any such payment in the form of a severance payment equallump sum 60 days following such termination of employment. In addition, whether in the context of a Change in Control or otherwise, (x) if the executive elects to continue his health insurance coverage under COBRA, then we will reimburse the executive for the same portion of the executive’s monthly premium over such 12-month period as we are then paying for health insurance coverage for active employees, and (y) to the extent not otherwise addressed by any equity-based compensation arrangements, the executive will be entitled to 12 months of his base salary pluscredited vesting beyond the employment termination date for any outstanding equity-based awards. The severance benefits are subject to the executive having been continuously employed through the termination event as well as executing and delivering a payment equal to 30%general release and waiver of base salaryclaims in lieufavor of us. The timing of any potential bonus, in addition any earned but unpaid bonus. In addition, vesting of stock options will accelerate in full. We will also reimburse Mr. Warma for COBRA expenses for a 12-month period,payments to the executive under the employment agreement are subject to a cap equalapplicable requirements of Section 409A of the Internal Revenue Code of 1986 and the related Treasury Regulations and may be delayed or reformed to Opexa’s standard contribution to employee health benefits. Uponcomply with such provisions. In the effectiveness of a change in control, as defined in the agreement, Mr. Warma will receive 18 months of salary and COBRA reimbursement and a payment equal to 45% of base salary in lieu ofevent any potential bonus, in addition to any earned but unpaid bonus. In addition, all vesting of options will accelerate in full. Any payment or benefit Mr. Warmathe executive might be entitled to receive upon a change of control which would constitute a “parachute payment” under Section 280G of the Internal Revenue Code, such payment or benefit will be reduced so as not to trigger excise tax under Section 4999 of such Code. Mr. Warma’s agreement also provides that for a 12-month period following his termination of employment, he will not engage or participate in any competitive business or solicit or recruit any of our employees. The severance and change of control benefits are subject to Mr. Warma executing and delivering a general release and waiver of claims in favor of Opexa.

Don Healey, Ph.D. We entered into an employment agreement with Don Healey on March 4, 2010, pursuant to which Mr. Healey serves as our Chief Scientific Officer. Mr. Healey is currently compensated at the rate of $270,000 per annum and is eligible to receive an annual discretionary bonus of up to 35% of his base salary per 12-month period, based on the achievement of objectives as determined by Opexa’s Board and Chief Executive Officer. In addition, Mr. Healey receives our standard benefits and insurance coverage as generally provided to our management, as well as contractual indemnification rights by reason of his service as an officer and employee. Mr. Healey’s employment may be terminated at any time voluntarily by him or without cause (as defined in the agreement) by the Board. If his employment is terminated by the Board without cause, Mr. Healey will be entitled to receive a severance payment equal to six months of his base salary. The severance benefits are subject to Mr. Healey having been continuously employed through the termination event, executing and delivering a general release and waiver of claims in favor of Opexa, not being in breach of the employment agreement or Opexa’s proprietary information and inventions agreement, and not engaging in any activity which is competitive with Opexa during the term of the employment agreement or while receiving the severance benefits. The timing of any payments to Mr. Healey under the employment agreement is subject to applicable requirements of Section 409A of the Code and the related Treasury Regulations.

Karthik Radhakrishnan. Mr. Radhakrishnan was employed as our Chief Financial Officer from March 29, 2013 until his employment terminated on March 2, 2016 as part of a restructuring initiative and reduction-in-force which occurred on that date. Pursuant to the terms of his March 2013 offer letter, he will be entitled to receive severance payments equal to six months of his base salary and vesting for any unvested stock options will accelerate by six additional months. In addition, Mr. Radhakrishnan will have a period of 12 months following his termination of employment within which to exercise any vested options, as opposed to the three months otherwise available for terminating employees. The severance benefits are subject to Mr. Radhakrishnan executing and delivering a general release and waiver of claims in favor of the Company, not being in breach of the offer letter or the Company’s proprietary information and inventions agreement, and not engaging in any activity which is competitive with the Company while receiving the severance benefits. Mr. Radhakrishnan’s salary at the time of his termination was $275,000 per annum. The timing of any payments to Mr. Radhakrishnan is subject to applicable requirements of Section 409A of the Code and the related Treasury Regulations.

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20152022 Outstanding Equity Awards at Fiscal Year-End

The following table presents information regarding outstanding equity awards at December 31, 20152022 for each of the Named Executive Officers.

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Certain Relationships and Related Party Transactions

In accordance with our Audit Committee charter, our Audit Committee is responsible for reviewing and approving the terms and conditions of any related party transactions. Review of any related party transaction would include reviewing each such transaction for potential conflicts of interests and other improprieties. Other than the compensation arrangements of our directors and Named Executive Officers discussed elsewhere in this Proxy Statement and as described in “Transactions with Related Persons” below, since January 1, 2022, there has not been, nor is there currently proposed, any transaction or series of similar transactions, to which we are or were a party, in which the amount involved exceeds or $120,000 or 1% of the average of our total assets at year-end for the last two completed fiscal years and in which any of our directors, executive officers, or holders of more than 5% of our capital stock, or any of the immediate family members of such persons, had or will have a direct or indirect material interest.

In addition to indemnification provisions in our bylaws, we have entered into agreements to indemnify our directors and executive officers. These agreements provide for indemnification of our directors and executive officers for certain types of expenses, including attorneys’ fees, judgments, fines, and settlement amounts incurred by persons in any action or proceeding, including any action by us or in our right, arising out of their services as our director or executive officer. We believe that these provisions and agreements are necessary to attract and retain qualified persons as directors and executive officers.

Transactions with Related Persons

Since January 1, 2015,2021, we have engaged in nothe following reportable transactions with our directors, executive officers, beneficial holders of more than 5% of our voting securities, and affiliates or their immediate family members.members:

On November 29, 2022, we entered into a securities purchase agreement for the sale and issuance of an aggregate of 1,229,508 shares of our common stock, for an aggregate purchase price of $1.5 million, in a private placement transaction at a price per share of $1.22, which represented a 5.2% premium to the $1.16 closing price of the common stock on that day. The shares were purchased by the following directors, executive officers and employees:

The shares of common stock issued in the private placement constitute “restricted securities” under the federal securities laws and were subject to a minimum six-month holding period. The private placement closed on December 2, 2022.

Securities Authorized for Issuance Under Equity Compensation Plans

The following table sets forth information, as of December 31, 2022, with respect to our compensation plans under which common stock is authorized for issuance. These plans consist of our 2018 Stock Incentive Plan, 2013 Stock Incentive Plan, and 2010 Stock Incentive Plan. We believe that the exercise price for all of the options granted under these plans reflect at least 100% of fair market value on the dates of grant for the options at issue.

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Equity Compensation Plan Information

Pay Versus Performance Table

The following table shows the total compensation for our Named Executive Officers for the past two fiscal years as set forth in the Summary Compensation Table, the “compensation actually paid” to our Chief Executive Officer (Chris Schelling), and on an average basis, our other Named Executive Officers (in each case, as determined under SEC rules), our total stockholder return (“TSR”) and our net income.

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The valuation assumptions and processes used to recalculate fair values did not materially differ from those disclosed at the time of grant.

(d) “Compensation actually paid” does not necessarily represent cash and/or equity value transferred to the applicable Named Executive Officer without restriction, but rather is a value calculated under applicable SEC rules.

Narrative Disclosure to Pay Versus Performance Table

The charts below show the relationship of “compensation actually paid” to (i) the Company’s TSR; and (ii) the Company’s net income. The following graphs illustrate the alignment between compensation actually paid to our Named Executive Officers and the Company’s performance. Specifically, a large portion of the Named Executive Officers’ compensation is reliant on TSR and as such the Chief Executive Officer and other Named Executive Officers’ “compensation actually paid” each year was aligned with our TSR performance and increased when our TSR performance increased but declined when our TSR performance declined.

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SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT

Beneficial Ownership

The following table sets forth, as of March 31, 2016,30, 2023, the number and percentage of outstanding shares of our common stock beneficially owned by: (a) each person who is known by us to be the beneficial owner of more than 5% of our outstanding shares of common stock; (b) each of our directors;directors and nominees; (c) theour Named Executive Officers; and (d) all current directors and executive officers as a group. As of March 31, 2016,30, 2023 there were 6,982,90923,421,534 shares of common stock issued and outstanding.

Beneficial ownership has been determined in accordance with Rule 13d-3 under the Exchange Act. Under this rule, certain shares may be deemed to be beneficially owned by more than one person (if, for example, persons share the power to vote or the power to dispose of the shares). In addition, shares are deemed to be beneficially owned by a person if the person has the right to acquire shares (for example, upon exercise of an option or warrant) within 60 days of the date as of which the information is provided. In computing the percentage ownership of any person, the amountnumber of shares is deemed to include the amountnumber of shares beneficially owned by such person by reason of such acquisition rights. As a result, the percentage of outstanding shares of any person as shown in the following table does not necessarily reflect the person’s actual voting power at any particular date.

To our knowledge, except as indicated in the footnotes to this table and pursuant to applicable community property laws, the persons named in the table have sole voting and investment power with respect to all shares of common stock shown as beneficially owned by them.

Beneficial Ownership Table

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Delinquent Section 16(a) Beneficial Ownership Reporting ComplianceReports

Section 16(a) of the Exchange Act requires our directors and executive officers, and persons who beneficially own more than 10% of a registered class of our equity securities, to file with the SEC initial reports of ownership and reports of changes in ownership. These reporting persons are required by SEC regulations to furnish us with copies of all such reports they file. To our knowledge, based solely on our review of the copies of such reports furnished to us and written representations from certain insiders that no other reports were required, we believe that all of the reporting persons complied with all applicable Section 16(a) filing requirements applicable to them with respect to transactions during the fiscal year ended December 31, 2015.2022 except as follows: Mr. Paul filed a Form 4 on January 21, 2022 with respect to an acquisition that was required to be filed by January 19, 2022.

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HOUSEHOLDING

The SEC has adopted rules that permit companies and intermediaries (e.g., brokers) to satisfy the delivery requirements for proxy statements and annual reports with respect to two or more shareholdersstockholders sharing the same address by delivering a single proxy statement addressed to those shareholders.stockholders. This process, which is commonly referred to as “householding,” potentially means extra convenience for shareholdersstockholders and cost savings for companies.

A number of brokers with account holders who are our shareholdersstockholders may be “householding” our proxy materials. If householding is in effect, a single proxy statement will be delivered to multiple shareholdersstockholders sharing an address unless contrary instructions have been received from the affected shareholders.stockholders. Once you have received notice from your broker that they will be “householding” communications to your address, “householding” will continue until you are notified otherwise or until you revoke your consent. If, at any time, you no longer wish to participate in “householding” and would prefer to receive a separate copy of the proxy statement and annual report, please notify your broker. ShareholdersStockholders who currently receive multiple copies of the proxy statement and/or annual report at their address and would like to request “householding” of their communications should contact their broker. We will deliver a separate set of proxy materials promptly upon written or oral request from a shareholder.stockholder. Please direct any such requests to Investor Relations, OpexaAcer Therapeutics Inc., 2635 Technology Forest Blvd., The Woodlands, Texas 77381,One Gateway Center, Suite 356, 300 Washington Street, Newton, Massachusetts 02458, or call Investor Relations at (281) 272-9331.(844) 902-6100.

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OTHER BUSINESS

The Board knows of no other business to come before the Annual Meeting. However, if any other matters are properly brought before the Annual Meeting, the person named in the accompanying form of proxy or his or theirher substitutes will vote in their discretion on those matters.

By Order of the Board of Directors,

Neil K. Warma/s/ Chris Schelling

Chris Schelling

Founder, President and Chief Executive Officer

April 11, 201614, 2023

The Woodlands, TexasNewton, Massachusetts

WHETHER OR NOT YOU PLAN TO ATTEND THE ANNUALVIRTUAL MEETING, PLEASE COMPLETE, SIGN, DATE, AND PROMPTLY RETURN THE ACCOMPANYING PROXY IN THE ENCLOSED ENVELOPE OR USE ONE OFVOTE BY INTERNET OR BY FOLLOWING THE VOTING METHODS DESCRIBED IN THE ATTACHED MATERIALS.INSTRUCTIONS ON YOUR VOTE INSTRUCTION FORM. YOU MAY REVOKE YOUR PROXY AT ANY TIME PRIOR TO THE ANNUAL MEETING. IF YOU DECIDE TO ATTEND THE ANNUALVIRTUAL MEETING AND WISH TO CHANGE YOUR PROXY VOTE, YOU MAY DO SO AUTOMATICALLY BY VOTING IN PERSONELECTRONICALLY AT THE MEETING.MEETING IF YOU ARE A STOCKHOLDER OF RECORD. IF YOUR SHARES ARE HELD OF RECORD BY A BROKER, BANK OR OTHER NOMINEE AND YOU WISH TO ATTEND AND VOTE IN PERSON AT THE MEETING, YOU MUST OBTAIN FROM THE RECORD HOLDER A LEGAL PROXY ISSUED IN YOUR NAME.

THANK YOU FOR YOUR ATTENTION TO THIS MATTER. YOUR PROMPT RESPONSE WILL GREATLY

FACILITATE ARRANGEMENTS FOR THE ANNUAL MEETING.

If you need additional copies of this Proxy Statement or the enclosed proxy card, or if you have other questions about the proposals or how to vote your shares, you may contact our proxy solicitor:

ADVANTAGE PROXY

(877) 870-8565 (toll free)

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Appendix A

OPEXA THERAPEUTICS, INC.

AMENDED AND RESTATED 2010 STOCK INCENTIVE PLAN

(Adopted by the Board of Directors initially on September 2, 2010, and

as amended and restated on September 25, 2013 and March 29, 2016)