Document:

Exhibit 10.3
    

    
      REGISTRATION RIGHTS AGREEMENT
    

    
      This Registration Rights Agreement (the “Agreement”)
      is made and entered into as of this 14th day of April, 2009,
      by and among Opexa Therapeutics, Inc., a Texas corporation (the “Company”),
      and the “Investors” named in that certain Unit
      Purchase Agreement by and among the Company and the Investors (the “Purchase
      Agreement”).
    

    
      The parties hereby agree as follows:
    

    
      1.  Certain Definitions.
    

    
      As used in this Agreement, the following terms shall have the following
      meanings:
    

    
      “Affiliate” shall mean, with respect to any person,
      any other person which directly or indirectly controls, is controlled
      by, or is under common control with, such person.
    

    
      “Business Day” shall mean a day, other than a
      Saturday or Sunday, on which banks in New York City are open for the
      general transaction of business.
    

    
      “Common Stock” shall mean the Company’s common
      stock, par value $0.50 per share, and any securities into which such
      shares may hereinafter be reclassified.
    

    
      “Investors” shall mean the Investors identified in
      the Purchase Agreement and any Affiliate of any Investor who is a
      subsequent holder of any Registrable Securities.
    

    
      “Issuable Shares” shall mean the shares of Common
      Stock issuable upon the conversion of the Notes and upon the exercise of
      the Warrants.
    

    
      “Notes” shall mean the Convertible Secured
      Promissory Notes issued to the Investors pursuant to the Purchase
      Agreement, a form of which is attached to the Purchase Agreement as
      Exhibit A.
    

    
      “Prospectus” shall mean (i) the prospectus included
      in any Registration Statement, as amended or supplemented by any
      prospectus supplement, with respect to the terms of the offering of any
      portion of the Registrable Securities covered by such Registration
      Statement and by all other amendments and supplements to the prospectus,
      including post-effective amendments and all material incorporated by
      reference in such prospectus, and (ii) any “free writing prospectus” as
      defined in Rule 405 under the 1933 Act.
    

    
      “Register,” “registered”
      and “registration” refer to a registration made by
      preparing and filing a Registration Statement or similar document in
      compliance with the 1933 Act (as defined below), and the declaration or
      ordering of effectiveness of such Registration Statement or document.
    

    
      “Registrable Securities” shall mean (i) the Issuable
      Shares and (ii) any other securities issued or issuable with respect to
      or in exchange for Registrable Securities; provided, that, a security
      shall cease to be a Registrable Security upon (a) a Registration
      Statement with respect to the sale of such securities shall have become
      effective under the 1933 Act and such securities shall have been sold,
      transferred, disposed of or exchanged pursuant to such Registration
      Statement, (b) such securities shall have been otherwise transferred,
      new certificates for them not bearing a legend restricting further
      transfer shall have been delivered by the Company and subsequent public
      distribution of them shall not require registration under the 1933 Act,
      (c) such securities shall have ceased to be outstanding, or (d) such
      securities are saleable under Rule 144 of the 1933 Act without regard to
      any volume limitation requirements under Rule 144 of the 1933 Act.
    

    
      
        

        

      

      
        

        

        
          

        

      

      
        

        

      

    

    
      “Registration Statement” shall mean any registration
      statement of the Company filed under the 1933 Act that covers the resale
      of any of the Registrable Securities pursuant to the provisions of this
      Agreement, amendments and supplements to such Registration Statement,
      including post-effective amendments, all exhibits and all material
      incorporated by reference in such Registration Statement.
    

    
      “Rights Holder” shall mean any Investor.
    

    
      “SEC” shall mean the U.S. Securities and Exchange
      Commission.
    

    
      “Warrants” shall mean, the Series G Warrants to
      purchase shares of Common Stock issued to the Investors pursuant to the
      Purchase Agreement, a form of which is attached to the Purchase
      Agreement as Exhibit B.
    

    
      “1933 Act” shall mean the Securities Act of 1933, as
      amended, and the rules and regulations promulgated thereunder.
    

    
      “1934 Act” shall mean the Securities Exchange Act of
      1934, as amended, and the rules and regulations promulgated thereunder.
    

    
      2.  Demand Registration.
    

    
         (a)  Subject to the limits set forth below, at any time after
      September 27, 2009, one or more Rights Holders holding at least forty
      (40) percent of the Registrable Securities (collectively, the “Required
      Holders”) shall have the right, by delivering written notice to
      the Company (a “Demand Notice”), to require the
      Company to register, pursuant to the terms of Section 4 under and in
      accordance with the provisions of the 1934 Act, the number of
      Registrable Securities requested to be so registered pursuant to the
      terms of this Agreement (a “Demand Registration”).  Within
      ten (10) days after receipt by the Company of a Demand Notice, the
      Company shall give written notice (the “Notice”) of
      such Demand Notice to all other Rights Holders and shall include in such
      registration all Registrable Securities with respect to which the
      Company received written requests  from such Rights Holders for
      inclusion therein within ten (10) days after such Notice is given by the
      Company to the Rights Holders.  A Demand Notice shall only be binding on
      the Company if the sale of all Registrable Securities requested to be
      registered (pursuant to such Demand Notice and in response to the
      Notice) is reasonably expected to result in aggregate gross proceeds in
      excess of $750,000.
    

    
         (b)  Following the receipt of a Demand Notice for a Demand
      Registration, the Company shall use its best efforts to file a
      Registration Statement as promptly as practicable, but not later than
      forty-five (45) days after such Demand Notice, and shall use its best
      efforts to cause such Registration Statement to be declared effective
      under the 1933 Act as promptly as practicable after the filing thereof.
    

    
      
        

        

      

      
        
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         (c)  The Required Holders shall be entitled to two (2) Demand
      Registrations; provided, however, that there shall be no
      limit to the number of Demand Registrations by Rights Holders that
      constitute “shelf” registrations as contemplated by the next succeeding
      sentence.  At such time when the Company is eligible to use Form S-3 (or
      comparable form) for the registration under the 1933 Act of any of its
      securities, the Required Holders shall be entitled to request that any
      Demand Registration be a “shelf” registration pursuant to Rule 415 under
      the 1933 Act, and the Required Holders shall be entitled to an unlimited
      number of Demand Registrations that constitute “shelf”
      registrations.  Notwithstanding any other provisions of this Section 2,
      in no event shall more than one Demand Registration occur within any
      six-month period from the effective date of any Registration Statement
      filed pursuant to a prior Demand Notice or within 120 days after the
      effective date of a Registration Statement filed by the Company; provided,
      however, that no Demand registration may be prohibited for such
      120-day period more often than once in a 12-month period.
    

    
         (d)  No Demand Registration shall be deemed to have occurred for
      purposes of this Section 2 if the Registration Statement relating
      thereto: (i) does not become effective, (ii) is not maintained effective
      for the period required pursuant to this Section 2 or (iii) the offering
      of the Registrable Securities pursuant to such Registration Statement is
      subject to a stop order, injunction or similar order or requirement of
      the SEC during such period.  In the case of each of clauses (i), (ii)
      and (iii), such requesting Rights Holders shall be entitled to an
      additional Demand Registration.
    

    
      3.  Piggy-Back Registration.
    

    
         (a)  Whenever the Company proposes to file a Registration Statement
      (other than in connection with a Demand Registration as provided in
      Section 2), at any time and from time to time, it will, prior to such
      filing, give written notice to all Rights Holders of its intention to do
      so.  Upon the written request of a Rights Holder given within ten (10)
      days after the Company provides such notice (which request shall state
      the intended method of disposition of such Registrable Securities), the
      Company shall use its best efforts to cause all Registrable Securities
      which the Company has been requested by such Rights Holder to register
      to be registered under the 1933 Act to the extent necessary to permit
      their sale or other disposition in accordance with the intended methods
      of distribution specified in the request of such Rights Holder; provided
      that the Company shall have the right to postpone or withdraw any
      registration effected pursuant to this Section 3 without obligation to
      any Rights Holder.
    

    
      
        

        

      

      
        
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         (b)  If the registration for which the Company gives notice pursuant
      to Section 3(a) is a registered public offering involving an
      underwriting, the Company shall so advise the Rights Holders as part of
      the written notice given pursuant to Section 3(a).  In such an event,
      the right of any Rights Holder to include its Registrable Securities in
      such registration pursuant to this Section 3 shall be conditioned upon
      such Rights Holder’s participation in such underwriting on the terms set
      forth herein.  All Rights Holders proposing to distribute their
      securities through such underwriting shall (together with the Company)
      enter into an underwriting agreement in customary form with the
      underwriter or underwriters selected for the underwriting by the
      Company.  Notwithstanding any other provision of this Section 3, if the
      managing underwriter determines that marketing factors require a
      limitation of the number of Shares to be underwritten, the Company may
      limit the number of Registrable Securities to be included in such
      registration and underwriting to not less than thirty (30) percent of
      the aggregate number of Shares to be underwritten.  The Company shall so
      advise all Rights Holders requesting registration, and the number of
      shares that are entitled to be included in the registration and
      underwriting shall be allocated in the following manner.  The number of
      shares that may be included in such registration and underwriting shall
      be allocated among all Rights Holders requesting registration in
      proportion, as nearly as practicable, to the respective number of
      Registrable Securities which they held at the time the Company gives the
      notice specified in Section 3(a).  If any Rights Holder would thus be
      entitled to include more securities than such Rights Holder requested to
      be registered, the excess shall be allocated among the other requesting
      Rights Holders pro-rata in the manner described in the preceding
      sentence.  If any Rights Holder disapproves of the terms of any such
      underwriting, such person may elect to withdraw therefrom by written
      notice to the Company, and any Registrable Securities or other
      securities excluded or withdrawn from such underwriting shall be
      withdrawn from such registration.
    

    
      4.  Registration.
    

    
         (a)  Registration Statements.  If and
      whenever the Company is required by the provisions of this Agreement to
      use its best efforts to effect the registration of any Registrable
      Securities under the 1933 Act, the Company shall prepare and file with
      the SEC one Registration Statement on Form S-3 (or, if Form S-3 is not
      then available to the Company, on such form of registration statement as
      is then available to effect a registration for resale of the Registrable
      Securities, subject to the prior written consent of the Required
      Holders), covering the resale of securities equaling (a) 100% of the
      Registrable Securities.  Subject to any SEC comments, such Registration
      Statement shall include the plan of distribution attached hereto as Exhibit
      A (the “Plan of Distribution”).  Such
      Registration Statement also shall cover, to the extent allowable under
      the 1933 Act (including Rule 416), such indeterminate number of
      additional shares of Common Stock resulting from stock splits, stock
      dividends or similar transactions with respect to the Registrable
      Securities.  Such Registration Statement shall not include any shares of
      Common Stock or other securities for the account of any other holder
      without the prior written consent of the Required Holders.  The
      Registration Statement (and each amendment or supplement thereto, and
      each request for acceleration of effectiveness thereof) shall be
      provided in accordance with Section 4(c) to the Rights Holders and their
      counsel prior to its filing or other submission.
    

    
         (b)  Expenses.  The Company will pay
      all expenses associated with each registration, including filing and
      printing fees, the Company’s counsel and accounting fees and expenses,
      costs associated with clearing the Registrable Securities for sale under
      applicable state securities laws, listing fees, fees and expenses of one
      counsel to the Rights Holders (not to exceed $15,000) and the Rights
      Holders’ reasonable expenses in connection with the registration, but
      excluding discounts, commissions, fees of underwriters, selling brokers,
      dealer managers or similar securities industry professionals with
      respect to the Registrable Securities being sold.
    

    
      
        

        

      

      
        
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         (c)  Effectiveness.
    

    
             (i)  The Company shall use reasonable best efforts to have the
      Registration Statement declared effective as soon as practicable.  Any
      request for acceleration of the Registration Statement shall seek
      effectiveness at 5:00 p.m., New York time, or as soon thereafter as
      practicable.  The Company shall notify the Rights Holders by facsimile
      or e-mail as promptly as practicable, and in any event, prior to 9:00
      a.m., New York time, on the day after any Registration Statement is
      declared effective, shall file with the SEC under Rule 424 a final
      Prospectus as promptly as practicable, and in any event, prior to 9:00
      a.m., New York time, on the day after any Registration Statement is
      declared effective, and shall advise the Rights Holders in writing that
      either (i) it has complied with the requirements of Rule 172 or (ii) it
      is unable to satisfy the conditions of Rule 172 and, as a result, Rights
      Holders are required to deliver a copy of the Prospectus in connection
      with any sales of Registrable Securities (in which case, the Company
      shall deliver to the Rights Holders a copy of the Prospectus to be used
      in connection with the sale or other disposition of the securities
      covered thereby).  If a Registration Statement covering the Registrable
      Securities is not declared effective by the SEC prior to the earlier of
      (A) five (5) Business Days after the SEC shall have informed the Company
      that no review of the Registration Statement will be made or that the
      SEC has no further comments on the Registration Statement or (B) the 120th
      day after the Closing Date (the 150th day after the Closing
      Date if the SEC comments on the Registration Statement) then the Company
      will make pro-rata payments to each Rights Holder, as liquidated damages
      and not as a penalty, in an amount equal to 1.0% of the aggregate amount
      invested by such Rights Holder for each 30-day period or pro-rata for
      any portion thereof following the date by which such Registration
      Statement should have been effective (the “Blackout Period”).  Such
      payments shall constitute the Rights Holders’ exclusive monetary remedy
      for such events, but shall not affect the right of the Rights Holders to
      seek injunctive relief.  The amounts payable as liquidated damages
      pursuant to this paragraph shall be paid monthly within three (3)
      Business Days of the last day of each month.  Provided, however, in no
      event shall such liquidated damages exceed 6% of the aggregate amount
      invested by the Rights Holder.  Such payments shall constitute the
      Rights Holders’ exclusive monetary remedy for such events, but shall not
      affect the right of the Rights Holders to seek injunctive relief.  Such
      payments shall be made to each Rights Holder in cash.
    

    
            (ii)  For not more than twenty (20) consecutive days or for a
      total of not more than forty-five (45) days in any twelve (12) month
      period, the Company may delay the disclosure of material non-public
      information concerning the Company, by suspending the use of any
      Prospectus included in any registration contemplated by this Section
      containing such information, the disclosure of which at the time is not,
      in the good faith opinion of the Company, in the best interests of the
      Company (an “Allowed Delay”); provided, that the
      Company shall promptly (a) notify the Rights Holders in writing of the
      existence of (but in no event, without the prior written consent of an
      Rights Holder, shall the Company disclose to such Rights Holder any of
      the facts or circumstances regarding) material non-public information
      giving rise to an Allowed Delay, (b) advise the Rights Holders in
      writing to cease all sales under the Registration Statement until the
      end of the Allowed Delay and (c) use reasonable best efforts to
      terminate an Allowed Delay as promptly as practicable.
    

    
         (d)  Limitation on Liquidated Damages.  Notwithstanding
      the other provisions of this Section 4, in no event shall the Company be
      liable for liquidated damages in excess of an aggregate of 6.0% of the
      aggregate amount invested by the Rights Holders pursuant to the Purchase
      Agreement.
    

    
      
        

        

      

      
        
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      5.  Company Obligations.  The Company will use its best
      efforts to effect the registration of the Registrable Securities in
      accordance with the terms hereof, and pursuant thereto the Company will,
      as expeditiously as possible:
    

    
         (a)  use its best efforts to cause such Registration Statement to
      become effective at 5:00 p.m., New York time, or as soon thereafter as
      practicable and to remain continuously effective for a period that will
      terminate upon the earlier of (i) the date on which all Registrable
      Securities covered by such Registration Statement as amended from time
      to time, have been sold, and (ii) the date on which all Registrable
      Securities covered by such Registration Statement may be sold pursuant
      to Rule 144 of the 1933 Act without regard to any volume limitation
      requirements under Rule 144 of the 1933 Act (the “Effectiveness
      Period”) and advise the Rights Holders in writing when the
      Effectiveness Period has expired;
    

    
         (b)  prepare and file with the SEC such amendments and post-effective
      amendments to the Registration Statement and the Prospectus as may be
      necessary to keep the Registration Statement effective for the
      Effectiveness Period and to comply with the provisions of the 1933 Act
      and the 1934 Act with respect to the distribution of all of the
      Registrable Securities covered thereby;
    

    
         (c)  furnish to each of the Rights Holders and their single
      designated legal counsel (i) promptly after the same is prepared and
      publicly distributed, filed with the SEC, or received by the Company
      (but not later than two (2) Business Days after the filing date, receipt
      date or sending date, as the case may be) one (1) copy of any
      Registration Statement and any amendment thereto, each preliminary
      prospectus and Prospectus and each amendment or supplement thereto, and
      each letter written by or on behalf of the Company to the SEC or the
      staff of the SEC, and each item of correspondence from the SEC or the
      staff of the SEC, in each case relating to such Registration Statement
      (other than any portion of any thereof which contains information for
      which the Company has sought confidential treatment), and (ii) such
      number of copies of a Prospectus, including a preliminary prospectus,
      and all amendments and supplements thereto and such other documents as
      each Rights Holder may reasonably request in order to facilitate the
      disposition of the Registrable Securities owned by such Rights Holder
      that are covered by the related Registration Statement;
    

    
         (d)  use reasonable best efforts to (i) prevent the issuance of any
      stop order or other suspension of effectiveness and, (ii) if such order
      is issued, obtain the withdrawal of any such order at the earliest
      possible moment;
    

    
         (e)  prior to any public offering of Registrable Securities, use best
      efforts to (i) register or qualify or cooperate with the Rights Holders
      and their counsel in connection with the registration or qualification
      of such Registrable Securities for offer and sale under the securities
      or blue sky laws of such jurisdictions requested by the Rights Holders
      and (ii) do any and all other acts or things necessary or advisable to
      enable the distribution in such jurisdictions of the Registrable
      Securities covered by the Registration Statement; provided, however,
      that the Company shall not be required in connection therewith or as a
      condition thereto to (i) qualify to do business in any jurisdiction
      where it would not otherwise be required to qualify but for this Section
      4(e), (ii) subject itself to general taxation in any jurisdiction where
      it would not otherwise be so subject but for this Section 4(e), or (iii)
      file a general consent to service of process in any such jurisdiction;
    

    
      
        

        

      

      
        
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         (f)  use reasonable best efforts to cause all Registrable Securities
      covered by a Registration Statement to be listed on each securities
      exchange, interdealer quotation system or other market on which similar
      securities issued by the Company are then listed;
    

    
         (g)  immediately notify the Rights Holders, at any time prior to the
      end of the Effectiveness Period, upon discovery that, or upon the
      happening of any event as a result of which, the Prospectus includes an
      untrue statement of a material fact or omits to state any material fact
      required to be stated therein or necessary to make the statements
      therein not misleading in light of the circumstances then existing, and
      promptly prepare, file with the SEC and furnish to such holder a
      supplement to or an amendment of such Prospectus as may be necessary so
      that such Prospectus shall not include an untrue statement of a material
      fact or omit to state a material fact required to be stated therein or
      necessary to make the statements therein not misleading in light of the
      circumstances then existing; and
    

    
         (h)  otherwise use best efforts to comply with all applicable rules
      and regulations of the SEC under the 1933 Act and the 1934 Act,
      including, without limitation, Rule 172 under the 1933 Act, file any
      final Prospectus, including any supplement or amendment thereof, with
      the SEC pursuant to Rule 424 under the 1933 Act, promptly inform the
      Rights Holders in writing if, at any time during the Effectiveness
      Period, the Company does not satisfy the conditions specified in Rule
      172 and, as a result thereof, the Rights Holders are required to deliver
      a Prospectus in connection with any disposition of Registrable
      Securities and take such other actions as may be reasonably necessary to
      facilitate the registration of the Registrable Securities hereunder; and
      make available to its security holders, as soon as reasonably
      practicable, but not later than the Availability Date (as defined
      below), an earnings statement covering a period of at least twelve (12)
      months, beginning after the effective date of each Registration
      Statement, which earnings statement shall satisfy the provisions of
      Section 11(a) of the 1933 Act, including Rule 158 promulgated thereunder
      (for the purpose of this subsection 4(h), “Availability Date”
      means the 45th day following the end of the fourth fiscal quarter that
      includes the effective date of such Registration Statement, except that,
      if such fourth fiscal quarter is the last quarter of the Company’s
      fiscal year, “Availability Date” means the 90th day
      after the end of such fourth fiscal quarter).
    

    
         (i)  With a view to making available to the Rights Holders the
      benefits of Rule 144 of the 1933 Act (or its successor rule) and any
      other rule or regulation of the SEC that may at any time permit the
      Rights Holders to sell shares of Common Stock to the public without
      registration, the Company covenants and agrees to:  (i) use its best
      efforts to make and keep public information available, as those terms
      are understood and defined in Rule 144, until the earlier of (A) six
      months after such date as all of the Registrable Securities may be
      resold pursuant to Rule 144 without regard to any volume limitation
      requirements under Rule 144 or (B) such date as all of the Registrable
      Securities shall have been resold; (ii) use its best efforts to file
      with the SEC in a timely manner all reports and other documents required
      of the Company under the 1934 Act; and (iii) furnish to each Rights
      Holder upon request, as long as such Rights Holder owns any Registrable
      Securities, (A) a written statement by the Company that it has complied
      with the reporting requirements of the 1934 Act, (B) a copy of the
      Company’s most recent Annual Report on Form 10-K or Quarterly Report on
      Form 10-Q, and (C) such other information as may be reasonably requested
      in order to avail such Rights Holder of any rule or regulation of the
      SEC that permits the selling of any such Registrable Securities without
      registration.
    

    
      
        

        

      

      
        
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      6.  Due Diligence Review; Information.  The Company
      shall make available, during normal business hours, for inspection and
      review by the Rights Holders, advisors to and representatives of the
      Rights Holders (who may or may not be affiliated with the Rights Holders
      and who are reasonably acceptable to the Company), all financial and
      other records, all SEC Filings (as defined in the Purchase Agreement)
      and other filings with the SEC, and all other corporate documents and
      properties of the Company as may be reasonably necessary for the purpose
      of such review, and cause the Company’s officers, directors and
      employees, within a reasonable time period, to supply all such
      information reasonably requested by the Rights Holders or any such
      representative, advisor or underwriter in connection with such
      Registration Statement (including, without limitation, in response to
      all questions and other inquiries reasonably made or submitted by any of
      them), prior to and from time to time after the filing and effectiveness
      of the Registration Statement for the sole purpose of enabling the
      Rights Holders and such representatives, advisors and underwriters and
      their respective accountants and attorneys to conduct initial and
      ongoing due diligence with respect to the Company and the accuracy of
      such Registration Statement.
    

    
      The Company shall not disclose material nonpublic information to the
      Rights Holders, or to advisors to or representatives of the Rights
      Holders, unless prior to disclosure of such information the Company
      identifies such information as being material nonpublic information and
      provides the Rights Holders, such advisors and representatives with the
      opportunity to accept or refuse to accept such material nonpublic
      information for review and any Rights Holder wishing to obtain such
      information enters into an appropriate confidentiality agreement with
      the Company with respect thereto.
    

    
      7.  Obligations of the Rights Holders.
    

    
         (a)  Each Rights Holder shall furnish in writing to the Company such
      information regarding itself, the Registrable Securities held by it and
      the intended method of disposition of the Registrable Securities held by
      it, as shall be reasonably required by the provisions of this Agreement
      to effect the registration of such Registrable Securities and shall
      execute such documents in connection with such registration as the
      Company may reasonably request, including a completed questionnaire in
      the form attached hereto as Exhibit B.  At least ten (10)
      Business Days prior to the first anticipated filing date of any
      Registration Statement, the Company shall notify each Rights Holder of
      the information the Company requires from such Rights Holder if such
      Rights Holder elects to have any of the Registrable Securities included
      in the Registration Statement.  An Rights Holder shall provide such
      information to the Company at least two (2) Business Days prior to the
      first anticipated filing date of such Registration Statement if such
      Rights Holder elects to have any of the Registrable Securities included
      in the Registration Statement.
    

    
         (b)  Each Rights Holder, by its acceptance of the Registrable
      Securities agrees to cooperate with the Company as reasonably requested
      by the Company in connection with the preparation and filing of a
      Registration Statement hereunder, unless such Rights Holder has notified
      the Company in writing of its election to exclude all of its Registrable
      Securities from such Registration Statement.
    

    
      
        

        

      

      
        
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         (c)  Each Rights Holder agrees that, upon receipt of any notice from
      the Company of either (i) the commencement of an Allowed Delay pursuant
      to Section 4(c)(ii) or (ii) the happening of an event pursuant to
      Section 4(g) hereof, such Rights Holder will immediately discontinue
      disposition of Registrable Securities pursuant to the Registration
      Statement covering such Registrable Securities, until the Rights Holder
      is advised by the Company that such dispositions may again be made.
    

    
      8.  Indemnification.
    

    
         (a)  Indemnification by the Company.  The
      Company will indemnify and hold harmless each Rights Holder and its
      officers, directors, members, employees and agents, successors and
      assigns, and each other person, if any, who controls such Rights Holder
      within the meaning of the 1933 Act, against any losses, claims, damages
      or liabilities, joint or several, to which they may become subject under
      the 1933 Act or otherwise, insofar as such losses, claims, damages or
      liabilities (or actions in respect thereof) arise out of or are based
      upon: (i) any untrue statement or alleged untrue statement of any
      material fact contained in any Registration Statement, any preliminary
      Prospectus or final Prospectus, or any amendment or supplement thereof;
      (ii) any blue sky application or other document executed by the Company
      specifically for that purpose or based upon written information
      furnished by the Company filed in any state or other jurisdiction in
      order to qualify any or all of the Registrable Securities under the
      securities laws thereof (any such application, document or information
      herein called a “Blue Sky Application”); (iii) the
      omission or alleged omission to state therein a material fact required
      to be stated therein or necessary to make the statements therein not
      misleading; (iv) any violation by the Company or its agents of any rule
      or regulation promulgated under the 1933 Act applicable to the Company
      or its agents and relating to action or inaction required of the Company
      in connection with such registration; or (v) any failure to register or
      qualify the Registrable Securities included in any such Registration in
      any state where the Company or its agents has affirmatively undertaken
      or agreed in writing that the Company will undertake such registration
      or qualification on an Rights Holder’s behalf and will reimburse such
      Rights Holder, and each such officer, director, member, employee, agent,
      successor and assign, and each such controlling person for any legal or
      other expenses reasonably incurred by them in connection with
      investigating or defending any such loss, claim, damage, liability or
      action; provided, however, that the Company will not be
      liable in any such case if and to the extent that any such loss, claim,
      damage or liability arises out of or is based upon an untrue statement
      or alleged untrue statement or omission or alleged omission so made in
      conformity with information furnished by such Rights Holder or any such
      controlling person in writing specifically for use in such Registration
      Statement or Prospectus.
    

    
      
        

        

      

      
        
          9
        

        
          

        

      

      
        

        

      

    

    
         (b)  Indemnification by the Rights Holders.  Each
      Rights Holder agrees, severally but not jointly, to indemnify and hold
      harmless, to the fullest extent permitted by law, the Company, its
      directors, officers, employees, stockholders and each person who
      controls the Company (within the meaning of the 1933 Act) against any
      losses, claims, damages, liabilities and expense (including reasonable
      attorney fees) resulting from any untrue statement of a material fact or
      any omission of a material fact required to be stated in the
      Registration Statement or Prospectus or preliminary Prospectus or
      amendment or supplement thereto or necessary to make the statements
      therein not misleading, to the extent, but only to the extent that such
      untrue statement or omission is contained in any information furnished
      in writing by such Rights Holder to the Company specifically for
      inclusion in such Registration Statement or Prospectus or amendment or
      supplement thereto.  In no event shall the liability of an Rights Holder
      be greater in amount than the dollar amount of the proceeds (net of all
      expense paid by such Rights Holder in connection with any claim relating
      to this Section 8 and the amount of any damages such Rights Holder has
      otherwise been required to pay by reason of such untrue statement or
      omission) received by such Rights Holder upon the sale of the
      Registrable Securities included in the Registration Statement giving
      rise to such indemnification obligation.  In addition, an Rights Holder
      shall not be liable hereunder to the extent that any such loss, claim,
      damage, liability (or action or proceeding in respect thereof) or
      expense arises out of the Company’s, or any underwriter’s, or their
      representatives’ failure to send or give a copy of a final Prospectus,
      as the same may be then supplemented or amended, to the person or entity
      asserting an untrue statement or alleged untrue statement or omission or
      alleged omission at or prior to the written confirmation of the sale of
      securities to such person or entity if such statement or omission was
      corrected in such final Prospectus.
    

    
         (c)  Conduct of Indemnification
      Proceedings.  Any person entitled to indemnification hereunder shall
      (i) give prompt notice to the indemnifying party of any claim with
      respect to which it seeks indemnification and (ii) permit such
      indemnifying party to assume the defense of such claim with counsel
      reasonably satisfactory to the indemnified party; provided that
      any person entitled to indemnification hereunder shall have the right to
      employ separate counsel and to participate in the defense of such claim,
      but the fees and expenses of such counsel shall be at the expense of
      such person unless (a) the indemnifying party has agreed to pay such
      fees or expenses, (b) the indemnifying party shall have failed to assume
      the defense of such claim and employ counsel reasonably satisfactory to
      such person or (c) in the reasonable judgment of any such person, based
      upon written advice of its counsel, a conflict of interest exists
      between such person and the indemnifying party with respect to such
      claims (in which case, if the person notifies the indemnifying party in
      writing that such person elects to employ separate counsel at the
      expense of the indemnifying party, the indemnifying party shall not have
      the right to assume the defense of such claim on behalf of such person);
      and provided, further, that the failure of any indemnified
      party to give notice as provided herein shall not relieve the
      indemnifying party of its obligations hereunder, except to the extent
      that such failure to give notice shall materially adversely affect the
      indemnifying party in the defense of any such claim or litigation.  It
      is understood that the indemnifying party shall not, in connection with
      any proceeding in the same jurisdiction, be liable for fees or expenses
      of more than one separate firm of attorneys at any time for all such
      indemnified parties.  No indemnifying party will, except with the
      consent of the indemnified party, consent to entry of any judgment or
      enter into any settlement that does not include as an unconditional term
      thereof the giving by the claimant or plaintiff to such indemnified
      party of a release from all liability in respect of such claim or
      litigation.
    

    
      
        

        

      

      
        
          10
        

        
          

        

      

      
        

        

      

    

    
         (d)  Contribution.  If for any reason
      the indemnification provided for in the preceding paragraphs (a) and (b)
      is unavailable to an indemnified party or insufficient to hold it
      harmless, other than as expressly specified therein, then the
      indemnifying party shall contribute to the amount paid or payable by the
      indemnified party as a result of such loss, claim, damage or liability
      in such proportion as is appropriate to reflect the relative fault of
      the indemnified party and the indemnifying party, as well as any other
      relevant equitable considerations.  No person guilty of fraudulent
      misrepresentation within the meaning of Section 11(f) of the 1933 Act
      shall be entitled to contribution from any person not guilty of such
      fraudulent misrepresentation.  In no event shall the contribution
      obligation of a holder of Registrable Securities be greater in amount
      than the dollar amount of the proceeds (net of all expenses paid by such
      holder in connection with any claim relating to this Section 8 and the
      amount of any damages such holder has otherwise been required to pay by
      reason of such untrue or alleged untrue statement or omission or alleged
      omission) received by it upon the sale of the Registrable Securities
      giving rise to such contribution obligation.
    

    
      9.  Miscellaneous.
    

    
         (a)  Amendments and Waivers.  This
      Agreement may be amended only by a writing signed by the Company and the
      Required Holders.  The Company may take any action herein prohibited, or
      omit to perform any act herein required to be performed by it, only if
      the Company shall have obtained the written consent to such amendment,
      action or omission to act, of the Required Holders.
    

    
         (b)  Notices.  All notices and other
      communications provided for or permitted hereunder shall be made as set
      forth in Section 9.4 of the Purchase Agreement.
    

    
         (c)  Assignments and Transfers by Rights
      Holders.  The provisions of this Agreement shall be binding upon and
      inure to the benefit of the Rights Holders and their respective
      successors and permitted assigns.  A Rights Holder may transfer or
      assign, in whole or from time to time in part, its rights hereunder in
      connection with the transfer of Registrable Securities by such Rights
      Holder only if such transferee or assignee receives at least 25,000
      Registrable Securities (adjusted for stock splits, stock dividends,
      stock combinations and similar corporate actions); provided, further,
      that such transferee or assignee shall execute a copy of this Agreement
      and that such Rights Holder complies with all laws applicable thereto
      and provides written notice of assignment to the Company promptly after
      such assignment is effected.
    

    
         (d)  Assignments and Transfers by the
      Company.  This Agreement may not be assigned by the Company (whether
      by operation of law or otherwise) without the prior written consent of
      the Required Holders, provided, however, that the Company may assign its
      rights and delegate its duties hereunder to any surviving or successor
      corporation in connection with a merger or consolidation of the Company
      with another corporation, or a sale, transfer or other disposition of
      all or substantially all of the Company’s assets to another corporation,
      without the prior written consent of the Required Holders, after notice
      duly given by the Company to each Rights Holder.
    

    
         (e)  Benefits of the Agreement.  The
      terms and conditions of this Agreement shall inure to the benefit of and
      be binding upon the respective permitted successors and assigns of the
      parties.  Nothing in this Agreement, express or implied, is intended to
      confer upon any party other than the parties hereto or their respective
      successors and assigns any rights, remedies, obligations, or liabilities
      under or by reason of this Agreement, except as expressly provided in
      this Agreement.
    

    
      
        

        

      

      
        
          11
        

        
          

        

      

      
        

        

      

    

    
         (f)  Counterparts; Faxes.  This
      Agreement may be executed in one or more counterparts, each of which
      shall be deemed an original, but all of which together shall constitute
      one and the same instrument.  This Agreement may also be executed via
      facsimile, which shall be deemed an original.
    

    
         (g)  Titles and Subtitles.  The
      titles and subtitles used in this Agreement are used for convenience
      only and are not to be considered in construing or interpreting this
      Agreement.
    

    
         (h)  Severability.  Any provision of
      this Agreement that is prohibited or unenforceable in any jurisdiction
      shall, as to such jurisdiction, be ineffective to the extent of such
      prohibition or unenforceability without invalidating the remaining
      provisions hereof but shall be interpreted as if it were written so as
      to be enforceable to the maximum extent permitted by applicable law, and
      any such prohibition or unenforceability in any jurisdiction shall not
      invalidate or render unenforceable such provision in any other
      jurisdiction.  To the extent permitted by applicable law, the parties
      hereby waive any provision of law which renders any provisions hereof
      prohibited or unenforceable in any respect.
    

    
         (i)  Further Assurances.  The parties
      shall execute and deliver all such further instruments and documents and
      take all such other actions as may reasonably be required to carry out
      the transactions contemplated hereby and to evidence the fulfillment of
      the agreements herein contained.
    

    
         (j)  Entire Agreement.  This
      Agreement is intended by the parties as a final expression of their
      agreement and intended to be a complete and exclusive statement of the
      agreement and understanding of the parties hereto in respect of the
      subject matter contained herein.  This Agreement supersedes all prior
      agreements and understandings between the parties with respect to such
      subject matter.
    

    
      
        

        

      

      
        
          12
        

        
          

        

      

      
        

        

      

    

    
         (k)  Governing Law; Consent to
      Jurisdiction; Waiver of Jury Trial.  This Agreement shall be
      governed by, and construed in accordance with, the internal laws of the
      State of Texas without regard to the choice of law principles
      thereof.  Each of the parties hereto irrevocably submits to the
      exclusive jurisdiction of the courts of the State of Texas located in
      Harris County and the United States District Court for the Southern
      District of Texas and the courts of the State of New York in the City of
      New York, Borough of Manhattan, and the United States District Court for
      the Southern District of New York for the purpose of any suit, action,
      proceeding or judgment relating to or arising out of this Agreement and
      the transactions contemplated hereby.  Service of process in connection
      with any such suit, action or proceeding may be served on each party
      hereto anywhere in the world by the same methods as are specified for
      the giving of notices under this Agreement.  Each of the parties hereto
      irrevocably consents to the jurisdiction of any such court in any such
      suit, action or proceeding and to the laying of venue in such
      court.  Each party hereto irrevocably waives any objection to the laying
      of venue of any such suit, action or proceeding brought in such courts
      and irrevocably waives any claim that any such suit, action or
      proceeding brought in any such court has been brought in an inconvenient
      forum.  EACH OF THE PARTIES HERETO WAIVES ANY RIGHT TO
      REQUEST A TRIAL BY JURY IN ANY LITIGATION WITH RESPECT TO THIS AGREEMENT
      AND REPRESENTS THAT COUNSEL HAS BEEN CONSULTED SPECIFICALLY AS TO THIS
      WAIVER.
    

    
      
        

        

      

      
        
          13
        

        
          

        

      

      
        

        

      

    

    
      IN WITNESS WHEREOF, the parties have executed this Agreement or caused
      their duly authorized officers to execute this Agreement as of the date
      first above written.
    

    
    	
          The Company:
        	
          OPEXA THERAPEUTICS, INC.
        
	

        	

        	
           
        
	

        	

        	
           
        
	

        	

        	
           
        
	

        	
          
            By:
          

        	
          
            /S/ NEIL K. WARMA
          

        
	

        	

        	
          Neil K. Warma
        
	

        	

        	
          President and Chief Executive Officer
        

    

    
      

      

      

      

    

    
      Signature Page to
Registration Rights Agreement
    

    

    

    
      
        

        

      

      
        

        

        
          

        

      

      
        

        

      

    

    
    	
          The Investor:
        	
           
        
	

        	
          [Print Investor’s Name]
        
	

        	

        	
           
        
	

        	

        	
           
        
	

        	
          
            By:
          

        	
          
             
          

        
	

        	
          
            Name:
          

        	
          
             
          

        
	

        	
          
            Title:
          

        	
          
             
          

        
	

        	

        	
           
        
	

        	

        	
           
        
	

        	

        	
           
        
	

        	
           
        
	

        	
          [Print Investor’s Name]
        
	

        	

        	
           
        
	

        	

        	
           
        
	

        	
          
            By:
          

        	
          
             
          

        
	

        	
          
            Name:
          

        	
          
             
          

        
	

        	
          
            Title:
          

        	
          
             
          

        

    

    
      

      

      

      

      Signature Page to
Registration Rights Agreement
    

    
      
        

        

      

      
        

        

        
          

        

      

      
        

        

      

    

    

    

    
      Exhibit A
    

    
      Plan of Distribution
    

    
      The selling stockholders, which as used herein includes donees,
      pledgees, transferees or other successors-in-interest selling shares of
      common stock or interests in shares of common stock received after the
      date of this prospectus from a selling stockholder as a gift, pledge,
      partnership distribution or other transfer, may, from time to time,
      sell, transfer or otherwise dispose of any or all of their shares of
      common stock or interests in shares of common stock on any stock
      exchange, market or trading facility on which the shares are traded or
      in private transactions.  These dispositions may be at fixed prices, at
      prevailing market prices at the time of sale, at prices related to the
      prevailing market price, at varying prices determined at the time of
      sale, or at negotiated prices.
    

    
      The selling stockholders may use any one or more of the following
      methods when disposing of shares or interests therein:
    

    	
        ordinary brokerage transactions and transactions in which the
        broker-dealer solicits purchasers;
      
	
        block trades in which the broker-dealer will attempt to sell the
        shares as agent, but may position and resell a portion of the block as
        principal to facilitate the transaction;
      
	
        purchases by a broker-dealer as principal and resale by the
        broker-dealer for its account;
      
	
        an exchange distribution in accordance with the rules of the
        applicable exchange;
      
	
        privately negotiated transactions;
      
	
        short sales effected after the date the registration statement of
        which this prospectus is a part is declared effective by the SEC;
      
	
        through the writing or settlement of options or other hedging
        transactions, whether through an options exchange or otherwise;
      
	
        broker-dealers may agree with the selling stockholders to sell a
        specified number of such shares at a stipulated price per share;
      
	
        a combination of any such methods of sale; and
      
	
        any other method permitted by law.
      

    
      The selling stockholders may, from time to time, pledge or grant a
      security interest in some or all of the shares of common stock owned by
      them and, if they default in the performance of their secured
      obligations, the pledgees or secured parties may offer and sell the
      shares of common stock, from time to time, under this prospectus, or
      under an amendment to this prospectus under Rule 424(b)(3) or other
      applicable provision of the Securities Act amending the list of selling
      stockholders to include the pledgee, transferee or other successors in
      interest as selling stockholders under this prospectus.  The selling
      stockholders also may transfer the shares of common stock in other
      circumstances, in which case the transferees, pledgees or other
      successors in interest will be the selling beneficial owners for
      purposes of this prospectus.
    

    
      

      

      Exhibit A – Page 1
    

    
      
        

        

      

      
        

        

        
          

        

      

      
        

        

      

    

    
      In connection with the sale of our common stock or interests therein,
      the selling stockholders may enter into hedging transactions with
      broker-dealers or other financial institutions, which may in turn engage
      in short sales of the common stock in the course of hedging the
      positions they assume.  The selling stockholders may also sell shares of
      our common stock short and deliver these securities to close out their
      short positions, or loan or pledge the common stock to broker-dealers
      that in turn may sell these securities.  The selling stockholders may
      also enter into option or other transactions with broker-dealers or
      other financial institutions or the creation of one or more derivative
      securities which require the delivery to such broker-dealer or other
      financial institution of shares offered by this prospectus, which shares
      such broker-dealer or other financial institution may resell pursuant to
      this prospectus (as supplemented or amended to reflect such transaction).
    

    
      The aggregate proceeds to the selling stockholders from the sale of the
      common stock offered by them will be the purchase price of the common
      stock less discounts or commissions, if any.  Each of the selling
      stockholders reserves the right to accept and, together with their
      agents from time to time, to reject, in whole or in part, any proposed
      purchase of common stock to be made directly or through agents.  We will
      not receive any of the proceeds from this offering. Upon any exercise of
      the warrants by payment of cash, however, we will receive the exercise
      price of the warrants.
    

    
      The selling stockholders also may resell all or a portion of the shares
      in open market transactions in reliance upon Rule 144 under the
      Securities Act of 1933, provided that they meet the criteria and conform
      to the requirements of that rule.
    

    
      The selling stockholders and any underwriters, broker-dealers or agents
      that participate in the sale of the common stock or interests therein
      may be "underwriters" within the meaning of Section 2(11) of the
      Securities Act.  Any discounts, commissions, concessions or profit they
      earn on any resale of the shares may be underwriting discounts and
      commissions under the Securities Act.  Selling stockholders will be
      subject to the prospectus delivery requirements of the Securities Act,
      unless an exemption therefrom is available.
    

    
      To the extent required, the shares of our common stock to be sold, the
      names of the selling stockholders, the respective purchase prices and
      public offering prices, the names of any agents, dealer or underwriter,
      any applicable commissions or discounts with respect to a particular
      offer will be set forth in an accompanying prospectus supplement or, if
      appropriate, a post-effective amendment to the registration statement
      that includes this prospectus.
    

    
      In order to comply with the securities laws of some states, if
      applicable, the common stock may be sold in these jurisdictions only
      through registered or licensed brokers or dealers.  In addition, in some
      states the common stock may not be sold unless it has been registered or
      qualified for sale or an exemption from registration or qualification
      requirements is available and is complied with.
    

    
      

      

      Exhibit A – Page 2
    

    
      
        

        

      

      
        

        

        
          

        

      

      
        

        

      

    

    
      There can be no assurance that any selling shareholder will sell any or
      all of the shares of common stock registered pursuant to the shelf
      registration statement, of which this prospectus forms a part.
    

    
      We have advised the selling stockholders that the anti-manipulation
      rules of Regulation M under the Exchange Act may apply to sales of
      shares in the market and to the activities of the selling stockholders
      and their affiliates.  In addition, to the extent applicable we will
      make copies of this prospectus (as it may be supplemented or amended
      from time to time) available to the selling stockholders for the purpose
      of satisfying the prospectus delivery requirements of the Securities
      Act.  The selling stockholders may indemnify any broker-dealer that
      participates in transactions involving the sale of the shares against
      certain liabilities, including liabilities arising under the Securities
      Act.
    

    
      We have agreed to indemnify the selling stockholders against
      liabilities, including liabilities under the Securities Act and state
      securities laws, relating to the registration of the shares offered by
      this prospectus.
    

    
      We will pay all our expenses of the registration of the shares of common
      stock pursuant to the registration rights agreement, estimated to be
      $[     ] in total, including, without limitation, Securities and
      Exchange Commission filing fees and expenses of compliance with state
      securities or "blue sky" laws and up to $15,000 of the selling
      stockholders expenses; provided, however, that a selling shareholder
      will pay all underwriting discounts and selling commissions, if any.
    

    
      We have agreed with the selling stockholders to keep the registration
      statement of which this prospectus constitutes a part effective until
      the earlier of (1) such time as all of the shares covered by this
      prospectus have been disposed of pursuant to and in accordance with the
      registration statement or (2) the date on which the shares may be sold
      pursuant to Rule 144 of the Securities Act without regard to any volume
      limitation requirements under Rule 144 of the Securities Act.
    

    
      

      

      Exhibit A – Page 3
    

    
      
        

        

      

      
        

        

        
          

        

      

      
        

        

      

    

    

    

    
      Exhibit B
    

    
      SELLING SHAREHOLDERS
QUESTIONNAIRE
    

    
      In connection with the preparation of the Registration Statement on Form
      S-3 of Opexa Therapeutics, Inc. (the “Company”), it
      is necessary that the Company obtain from you (“Selling
      Shareholder”) written verification of certain information
      required to be disclosed in the Registration Statement.
    

    
      Please use the utmost care in responding to this Questionnaire.  You
      should be aware that if the Registration Statement contains any false or
      misleading statements which are material, under certain circumstances
      the Company and those in control of the Company, including officers and
      directors, could be subject to liability.  If the answer to
      any of the questions is “no,” “none” or “not applicable,” please so
      indicate.  Please do not leave any questions unanswered.
    

    
      As used herein, “Fiscal Year” refers to the Company’s fiscal year ended December
      31, 2008, and for previous fiscal years.  Other italicized
      terms are defined in Appendix A to this Questionnaire.
    

    
      If at any time prior to the effectiveness of the Registration Statement
      you discover that your answer to any question was inaccurate, or if any
      event occurring subsequent to your completion hereof and prior to the
      effectiveness of the Registration Statement would require a change in
      your answers to any questions, please contact Neil Warma by
      telephone at (281) 719-3421 immediately.
    

    
      I hereby acknowledge, by my execution and dating of this Questionnaire
      in the places indicated below, that my answers to the following
      questions are true and correct to the best of my information and belief.
    

    

    

    
    	
          INVESTOR
        	

        	
           
        	

        
	

        	

        	

        	
           
        
	

        	

        	

        	
           
        
	
          By:
        	
           
        	

        	
           
        
	

        	
          (Signature)
        	

        	
          (Dated)
        
	

        	

        	

        	
           
        
	
          Printed Name:
        	
           
        	

        	

        
	

        	

        	

        	
           
        
	
          Office:
        	
           
        	

        	

        

    

    

    

    
      

      

      Exhibit B – Page 1
    

    
      
        

        

      

      
        

        

        
          

        

      

      
        

        

      

    

    

    

    
      I
GENERAL
      INFORMATION
    

    
      Question 1(a):
    

    
      Name:  Please set forth the full name of the Selling
      Shareholder.
    

    
      Answer:
    

    
      

      

      

    

    
      Question 1(b):
    

    
      If the Selling Shareholder is not a natural person, please indicate
      whether the Selling Shareholder is one of the following:  
    

    	
        a reporting company under the Exchange Act
      
	
        a majority owned subsidiary of a reporting company under the Exchange
        Act,
      
	
        a registered investment fund under the 1940 Act.
      

    
      Yes ___________     No ____________
    

    
      Question 1(c):
    

    
      If the Selling Shareholder is not one of the three above, identify those
      persons that have voting and investment control over the Company.
    

    
      Answer:
    

    
      

      

      

    

    
      Question 1(d):
    

    
      Is the Selling Shareholder an executive officer or director of the
      Company or 5% or more holder of Company shares of common stock.
    

    
      Yes ____________    No ______________
    

    
      
        

        

      

      
        

        

        
          

        

      

      
        

        

      

    

    
      Question 2:
    

    
      Family Relationships.  If you have any family relationship, by
      blood, marriage or adoption not more remote than first cousin, with any
      director, executive officer, or nominee to become a director or
      executive officer of the Company, its parent, any of its
      subsidiaries, or other affiliates, or any individual who has been
      employed by the Company in the past three years as an executive
      officer, please identify such relative and describe the nature of
      the relationship.
    

    
      Answer:
    

    
      

      

      

    

    
      Question 3:
    

    
      Is the Selling Shareholder a broker dealer and/or member of the
      Financial Industry Regulatory Authority (“FINRA”) or
      a broker dealer’s affiliate and/or member of FINRA?
    

    
      Yes ___             No ___
    

    
      If a Selling Shareholder is a broker dealer and/or member of the
      FINRA, please indicate whether the Selling Shareholder acquired its
      securities as compensation for underwriting activities or
      investment purposes.  
    

    
      Yes ___             No ___
    

    
      If a Selling Shareholder is an affiliate of a broker dealer
      and/or member of the FINRA, please indicate whether this broker dealer’s
      affiliate:
    

    	
        purchased the securities to be resold in the ordinary course of
        business; and
      
	
        had no agreements or understandings, directly or indirectly, with any
        person to distribute the securities at the time of their purchase.
      

    
      Yes ___             No ___
    

    
      Is any member of your Immediate Family (by blood, marriage or adoption)
      a member of the FINRA.
    

    
      Yes ___             No ___
    

    
      If you marked “Yes” to any of the questions above, please briefly
      describe the facts below, giving the names of the broker dealer and/or
      member of the FINRA to which your answer refers (including, for example,
      percentage of ownership, amount of loan and interest payable, applicable
      dates, names of Affiliates, family, etc).
    

    
    	
           
        	
           
        
	
           
        	
           
        
	
           
        	
           
        
	
           
        	
           
        

    

    

    

    

    

    
      
        

        

      

      
        

        

        
          

        

      

      
        

        

      

    

    
      Question 4:
    

    
      State whether you provide any consulting or other services to the
      Company.
    

    
      Yes ___             No ___
    

    
      (a)       If you marked “Yes”, please briefly describe such services,
      including cash and non-cash compensation received and attach copies of
      written agreements or correspondence describing such services.
    

    
    	
           
        	
           
        
	
           
        	
           
        
	
           
        	
           
        
	
           
        	
           
        

    

    

    

    
      (b)       Please identify any of the following relationships you have
      with any Member of the FINRA.
    

    
    	
           
        	
          None
        	
          □
        
	

        	
          Advisor
        	
          □
        
	

        	
          Officer
        	
          □
        
	

        	
          Director
        	
          □
        
	

        	
          Trustee
        	
          □
        
	

        	
          Founder
        	
          □
        
	

        	
          Registered Representative
        	
          □
        
	

        	
          5% Stockholder
        	
          □
        
	

        	
          Employee
        	
          □
        
	

        	
          Immediate Family
        	
          □
        
	

        	
          Broker/Dealer
        	
          □
        
	

        	
          Promoter
        	
          □
        
	

        	
          Consultant
        	
          □
        
	

        	
          Finder
        	
          □
        
	

        	
          Bridge Lender
        	
          □
        
	

        	
          General Partner
        	
          □
        
	

        	
          Limited Partner
        	
          □
        
	

        	
          Equity Investor
        	
          □
        
	

        	
          Client or Customer
        	
          □
        
	

        	
          Subordinated Debt Holder
        	
          □
        
	

        	
          Other
        	
          □
        

    

    
      (c)       Please describe the nature of any relationship identified
      above.  For example, if you are an advisor, promoter, consultant or
      finder, describe the compensation you received; if you are an equity
      investor, state the class of securities and percentage interest you
      hold; and if you are an Immediate Family Member, describe the exact
      relationship, including the name of the person to whom you are related
      and the position such person holds with any Member of the
      FINRA.  Identify the Member of the FINRA:
    

    
    	
           
        	
           
        
	
           
        	
           
        
	
           
        	
           
        
	
           
        	
           
        

    

    

    

    
      
        

        

      

      
        

        

        
          

        

      

      
        

        

      

    

    
      (d)       State whether you have any oral and/or written agreements with
      any Member of the FINRA or Person Associated with a Member of FINRA
      concerning the disposition of your securities of the Company.
    

    
      Yes ___             No ___
    

    
      (e)       If you marked “Yes”, please briefly describe such agreement
      and attach copies of written agreements or correspondence describing
      such arrangement.
    

    
    	
           
        	
           
        
	
           
        	
           
        
	
           
        	
           
        
	
           
        	
           
        

    

    
      Question 5:
    

    
      Involvement in Certain Legal Proceedings.  Have any of the
      following events occurred during the last five years:
    

    
      (a)       Were you the subject of any order, judgment or decree of any
      court (not subsequently reversed, suspended or vacated by any court)
      permanently or temporarily enjoining you (i) from acting as a futures
      commission merchant, introducing broker, commodity trading advisor,
      commodity pool operator, floor broker, leverage transaction merchant,
      any other person regulated by the Commodity Futures Trading Commission (“CFTC”),
      or an associated person of any of the foregoing; or as an investment
      advisor, underwriter, broker or dealer in securities; or as an
      affiliated person, director or employee of any investment company, bank,
      savings and loan association or insurance company; or from engaging in
      or continuing any conduct or practice in connection with such activity;
      or (ii) from engaging in any type of business practice; or (iii) from
      engaging in any activity in connection with the purchase or sale of any
      security or commodity or in connection with any violation of federal or
      state securities laws or federal commodities laws?
    

    
      YES _______________ NO _______________
    

    
      (b)       Were you the subject of any order, judgment or decree of any
      federal or state authority barring, suspending or otherwise limiting for
      more than 60 days your right to engage in any activity described in
      subparagraph (a) above, or to be associated with persons engaged in any
      such activity?
    

    
      YES _______________ NO _______________
    

    
      
        

        

      

      
        

        

        
          

        

      

      
        

        

      

    

    
      (c)       Has any court, the SEC, CFTC, NYSE, American Stock Exchange,
      FINRA or any commodity exchange or NASDAQ imposed a sanction against you
      or found you to have violated any federal or state securities or
      commodities laws?
    

    
      YES _______________ NO _______________
    

    
      (d)       Do you or any of your associates have any claims against the
      Company or any of its subsidiaries; or are you or any of your associates
      a party adverse to the Company or any of its subsidiaries in any legal
      proceeding; or do you or any of your associates have a material interest
      adverse to the Company or any of its subsidiaries in any legal
      proceeding?
    

    
      YES _______________ NO _______________
    

    
      II
SECURITY
      OWNERSHIP
    

    
      Question 6: Your Securities Holdings.
    

    
      (a)       As to each class of equity
      securities of the Company, its parent or any subsidiary, state the
      total number of shares or other units beneficially owned by you
      as of the date hereof.
    

    
    	

        	
           
        	
          NUMBER OF SHARES
        
	
          TITLE OF EQUITY SECURITY
        	

        	
          BENEFICIALLY OWNED
        
	
          (Include warrant, options and convertible debt)
        	

        	

        
	
           
        	

        	
           
        
	
           
        	

        	
           
        
	
           
        	

        	
           
        
	
           
        	

        	
           
        

    

    

    

    
      If you listed any warrants, options, convertible debt or other
      derivative securities that are not fully vested, please set forth the
      vesting schedule below.
    

    
      Vesting Schedule(s):
    

    
      (b)       If, as a result of applying the rules regarding beneficial
      ownership summarized in the Appendix to this Questionnaire, you have
      included in the amount stated in answer to Question 6(a) above under
      “Number of Shares Beneficially Owned” shares not issued in your name,
      please provide details as to the nature of such beneficial ownership of
      such shares or other units and state the amount of shares or units so
      owned;
    

    
      
        

        

      

      
        

        

        
          

        

      

      
        

        

      

    

    
      Answer:
    

    
      

      

      

    

    
      (c)       If, as a result of applying the rules regarding beneficial
      ownership summarized in the Appendix to this Questionnaire, you have
      excluded from the amount stated in the answer to Question 6(a) above
      under “Number of Shares Beneficially Owned” shares or units which are
      issued in your name, please state the amount so excluded and explain why
      you are not the beneficial owner of such shares or units.
    

    
      Answer:
    

    
      

      

      

    

    
      (d)       Of the total number of shares or units beneficially
      owned by you, as reported in answer to Question 6(a), indicate below
      the amounts as to which you have sole or shared voting or investment
      power.
    

    
    	

        	
          Common Stock
        	
           
        	
          Other
(i.e. warrants, options or convertible debt)
        
	
          Sole voting power
        	
           
        	

        	
           
        
	
          Shared voting power
        	
           
        	

        	
           
        
	
          Sole investment power
        	
           
        	

        	
           
        
	
          Shared investment power
        	
           
        	

        	
           
        

    

    
      (e)       Does the Selling Shareholder have a registration rights
      agreement with the Company other than as described in the Purchase
      Agreement entered into in connection with this questionnaire?
    

    
      Yes_____________    No ______________
    

    
      If so, attach a copy.
    

    
      
        

        

      

      
        

        

        
          

        

      

      
        

        

      

    

    
      Question 7:  Disclaimer of Beneficial Ownership.
    

    
      (a)       If you wish to disclaim beneficial
      ownership of any securities referred to above, please set forth the
      number of such shares or units, the circumstances upon which the
      disclaimer of beneficial ownership is based, the name of the
      person or persons who should be shown as the beneficial owner(s) of such
      shares or units, and your relationship to that person or those persons.
    

    
      Answer:
    

    
      

      

      

    

    
      (b)       Do you or any of your affiliates
      or associates participate in investment decisions made by any
      nonprofit entity that owns Company securities? If yes, please provide
      details and indicate whether you disclaim beneficial ownership of
      such Company securities.
    

    
      YES _______________ NO _______________
    

    
      

      

    

    
      Question 8:
    

    
      Securities Holdings of Your Relatives.  If any equity
      securities of the Company, its parent or any subsidiary are beneficially
      owned by any relative of yours (by blood, marriage or adoption) who
      shares your home, please indicate below the name of each such relative,
      your relationship with him or her, and the amount of shares so owned.
    

    
      Answer:
    

    
      

      

      

    

    
      III
CERTAIN
      TRANSACTIONS AND RELATIONSHIPS
    

    
      Question 9:
    

    
      Transactions with Management.  In the table on the following
      page, describe any transaction (or series of similar transactions),
      during the Company’s last three Fiscal Years, or any currently proposed transaction
      (or series of similar transactions), to which the Company or any
      of its subsidiaries was or is to be a party, and in which you had or
      anyone in your immediate family has, a material direct or indirect
      financial interest.  Identify the person(s) involved and state the
      nature of your or their interest in the transaction, the amount
      of the transaction and the amount of your or their interest in
      the transaction. (Attach a supplemental page if necessary.)
    

    
      
        

        

      

      
        

        

        
          

        

      

      
        

        

      

    

    
    	
          Description of Transaction
        	
           
        	
          Persons Involved
        	
           
        	
          Nature of Interest
        	
           
        	
          Amount of Transaction
        	
           
        	
          Amount of Interest
        
	

        	

        	

        	

        	

        	

        	

        	

        	
           
        
	

        	

        	

        	

        	

        	

        	

        	

        	
           
        
	

        	

        	

        	

        	

        	

        	

        	

        	
           
        
	

        	

        	

        	

        	

        	

        	

        	

        	
           
        

    

    
      Question 10:
    

    
      Indebtedness of Management. If you or any associate of
      yours has been indebted to the Company or any of its subsidiaries at any
      time during the Company’s last three Fiscal Years, state: (a) the name
      of the indebted person; (b) if the indebted person is an associate,
      the nature of your relationship to that person; (c) the largest
      aggregate amount of indebtedness outstanding at any time during the
      Company’s last three Fiscal Years; (d) the nature of the indebtedness
      and of the transaction in which it was incurred; (e) the amount of
      indebtedness outstanding as of the latest practicable date (indicating
      that date); and (f) the rate of interest paid or charged thereon, if any.
    

    
      Include (with respect to yourself only) any instances where the Company,
      either directly or indirectly (including through a subsidiary), extended
      or maintained credit for you, arranged for the extension of credit, or
      renewed any extension of credit, in the form of a personal loan to or
      for you.
    

    
      Answer:
    

    
      

      

      

    

    
      
        

        

      

      
        

        

        
          

        

      

      
        

        

      

    

    

    

    
      APPENDIX A
DEFINITIONS
      OF CERTAIN TERMS
IN
      QUESTIONNAIRE
(Arranged
      alphabetically)
    

    
      1.        “Affiliate.”  An
      “affiliate” of any entity is a person that, directly or indirectly,
      through one or more intermediaries, controls, is controlled
      by or is under common control with such person (for example, a
      parent subsidiary or sister corporation).
    

    
      2.        “Associate.”  “Associate”
      for the purpose of Question 4 means (1) any corporation or organization
      (other than the Company or a majority-owned subsidiary of the Company)
      of which you are an officer or partner or are, directly or
      indirectly, the beneficial owner of 10% or more of any class of equity
      securities; (2) any trust or other estate in which you have a
      substantial beneficial interest or as to which you serve as a trustee or
      in a similar fiduciary capacity; and (3) any member of your immediate
      family.  ”Associate” for the purpose of Question 13 means the same
      as the foregoing, except that subsection (1) shall state ”any
      corporation or organization ... of which you are an executive
      officer ...”
    

    
      3.        “Beneficial
      Ownership.”
    

    
      a.        General Rule. Under the rules of the SEC, you are deemed to
      “beneficially own” or be the “beneficial owner” of any security with
      respect to which you have or share, directly or indirectly, through any
      contract, arrangement, understanding, relationship, agreement or
      otherwise: (1) Voting Power (which includes the power to vote, or to
      direct the voting of, such security); and/or (2) Investment Power (which
      includes the power to dispose, or to direct the disposition of, such
      security). You are also the beneficial owner of a security if you,
      directly or indirectly, create or use a trust, proxy, power of attorney,
      pooling arrangement or any other contract, arrangement, or device with
      the purpose or effect of divesting yourself of beneficial ownership of a
      security or preventing the vesting of such beneficial ownership.
    

    
      Some specific applications of the above definition of beneficial
      ownership are:
    

    
      (i) Family situations. Although the determination of beneficial
      ownership of securities is necessarily a question to be determined in
      light of the facts of each particular case, family relationships may
      result in your having, or sharing, the power to vote, or direct the
      voting of, or dispose, or direct the disposition of, shares held by your
      family members. In view of the broad definition of “Beneficial
      Ownership,” it may be prudent to include such shares in your beneficial
      ownership disclosure and then disclaim beneficial ownership of such
      securities pursuant to Question 6.
    

    
      (ii) Shares held by others for your benefit. There are numerous
      instances in which you may have, or share, voting or investment power
      (as defined above) over securities, although the securities are held by
      another person or entity. For example, you may have or share such power
      in securities held for you or your family members living with you by
      custodians, brokers, relatives, executors, administrators or trustees;
      securities held for your account by pledgees; securities owned by a
      partnership in which you are a member; and securities owned by a
      corporation which is or should be regarded as a personal holding company
      of yours or is controlled by you.
    

    
      

      

      Appendix A – Page 1
    

    
      
        

        

      

      
        

        

        
          

        

      

      
        

        

      

    

    
      (iii) Shares held by you for the benefit of others. Beneficial ownership
      of securities also includes securities held in your name as a trustee,
      custodian or other fiduciary where you have, or share, voting or
      investment power with respect to such securities.
    

    
      b.        Options and other rights to acquire securities. In addition to
      being beneficial owner of securities over which you have, or share,
      voting or investment power, the SEC has determined that you are deemed
      to be the beneficial owner of a security if you have a right to acquire
      beneficial ownership of (i.e., the right to obtain or share voting or
      investment power over) such security at any time within sixty days.
      Examples of such rights would include the right to acquire: (i) through
      the exercise of any option, warrant or similar right; (ii) through
      conversion of any security; or (iii) pursuant to the power to revoke, or
      the provision for automatic termination of, a trust, discretionary
      account or similar arrangement. Also, if you have acquired or hold any
      options, convertible securities or power to revoke such a trust with the
      “purpose or effect” of changing or influencing control of the Company,
      you are deemed the beneficial owner of the underlying securities upon
      such acquisition, without regard to the sixty-day rule stated above.
    

    
      4.        “Control.”  The
      term “control” means the possession, direct or indirect, of the power to
      direct or cause the direction of the management and policies of the
      Company, whether through the ownership of voting securities, by contract
      or otherwise. An executive officer or director of a company
      generally is considered to control that company. It is suggested that,
      if you are in doubt as to the meaning of “control” in a particular
      context, you communicate with counsel.
    

    
      5.        “Equity
      Security.”  The definition of “equity security” encompasses more
      than common and preferred stock. It includes for instance convertible
      debt instruments as well as warrants and options to acquire stock or
      similar securities. If you have a question as to the proper
      characterization of your holdings you should consult with the Company’s
      legal counsel.
    

    
      6.        “Executive
      Officer.”  “Executive officer” for the purpose of this
      Questionnaire means the president of a company, any vice president of it
      in charge of a principal business unit, division or function (such as
      sales, administration or finance), any other officer who performs
      a policy-making function or any other person who performs similar
      policy-making functions for the company. Executive officers of
      subsidiaries may be deemed executive officers of a company if they
      perform such policy-making functions for the company.
    

    
      7.        “Group.”  A
      “group” exists when two or more persons act as a partnership, limited
      partnership, syndicate or other group for the purpose of acquiring,
      holding or disposing of securities of any issuer.
    

    
      

      

      Appendix A – Page 2
    

    
      
        

        

      

      
        

        

        
          

        

      

      
        

        

      

    

    
      8.        “Immediate
      Family.”  “Immediate family” for the purpose of this
      Questionnaire includes your spouse, parents, children, siblings,
      mothers-and fathers-in-law, sons- and daughters-in-law, and brothers-
      and sisters-in-law.
    

    
      9.        “Officer.”  “Officer”
      means a president, vice president, secretary, treasurer or principal
      financial officer, comptroller or principal accounting officer, and any
      person routinely performing corresponding functions with respect to any
      organization whether incorporated or unincorporated.
    

    
      10.       “Person.”  “Person”
      for the purpose of this Questionnaire means an individual, a
      corporation, a partnership, an association, a joint-stock company, a
      business trust, an unincorporated organization, or any other entity.
    

    
      11.       “Personal
      Benefits.”  The SEC’s prior interpretive releases on what the
      SEC views as a personal benefit or a “perk,” were previously rescinded
      by Item 402 and as most recently revised, Item 402 does not specifically
      define “personal benefit.” Item 402, however, does not require
      disclosure of personal benefits for any individual if the aggregate
      amount paid to that individual is less than the lesser of (i) $50,000 or
      (ii) 10% of that individual's compensation. In general, the position of
      the SEC has been that benefits which are directly related to job
      performance, as well as benefits provided to broad categories of
      employees and which do not discriminate in scope or terms of operation
      in favor of officers and directors, may be omitted from the
      calculation of total compensation, while benefits not so related should
      be disclosed as compensation. If you have any questions, please resolve
      the issue in favor of disclosure. The Company will review the necessity
      for disclosure in the proxy statement with its counsel.
    

    
      12.       “Transaction
      or Transactions.”  “Transaction” or "transactions" is
      to be understood in its broadest sense, and includes the direct or
      indirect receipt of anything of value. No transaction or interest
      therein need be disclosed where: (a) the rates or charges involved in
      the transaction are determined by competitive bids, or the transaction
      involves the rendering of services as a common or contract carrier or
      public utility at rates or charges fixed in conformity with law or
      governmental authority; (b) the transaction involves services as a bank
      depository of funds, transfer agent, registrar, trustee under a trust
      indenture or similar services; or (c) the interest in question arises
      solely from the ownership of securities of the Company and the
      interested party receives no extra or special benefit not shared on a
      pro-rata basis by all shareholders.
    

    
      

      

      Appendix A – Page 3Exhibit 10.4
    

    
      THE SECURITIES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED UNDER THE
      SECURITIES ACT OF 1933 AS AMENDED (THE “ACT”), OR ANY STATE
      SECURITIES LAWS.  SUCH SECURITIES MAY NOT BE SOLD OR OTHERWISE
      TRANSFERRED EXCEPT AS PERMITTED UNDER THE ACT AND THE APPLICABLE STATE
      SECURITIES LAWS, PURSUANT TO REGISTRATION OR AN EXEMPTION
      THEREFROM.  THE ISSUER OF THESE SECURITIES MAY REQUIRE AN OPINION OF
      COUNSEL (WHICH MAY BE COUNSEL FOR THE COMPANY) IN FORM AND SUBSTANCE
      REASONABLY SATISFACTORY TO THE ISSUER TO THE EFFECT THAT ANY PROPOSED
      TRANSFER OR RESALE IS IN COMPLIANCE WITH THE ACT.
    

    
      SUBJECT TO THE PROVISIONS OF SECTION 10 HEREOF, THIS WARRANT SHALL BE
      VOID AFTER 5:00 P.M. EASTERN TIME ON APRIL 14, 2013, (THE “EXPIRATION
      DATE”).
    

    
    	
          No. G-__________
        	
          April 14, 2009
        

    

    
      OPEXA THERAPEUTICS, INC.
    

    
      SERIES G WARRANT TO PURCHASE ____
      SHARES OF
COMMON STOCK,
      PAR VALUE $0.50 PER SHARE
    

    
      For VALUE RECEIVED, _____________ (“Warrantholder”),
      is entitled to purchase, subject to the provisions of this Series G
      Warrant (the “Warrant”), from Opexa Therapeutics,
      Inc., a Texas corporation (“Company”), at any time
      from and after the date six months after the date hereof (the “Initial
      Exercise Date”) and not later than 5:00 P.M., Eastern time, on
      the Expiration Date (as defined above), at an exercise price per share
      equal to $0.75 (the exercise price in effect being herein called the “Warrant
      Price”), ____________ shares (“Warrant Shares”)
      of the Company’s Common Stock, par value $0.50 per share (“Common
      Stock”).  The number of Warrant Shares purchasable upon exercise
      of this Warrant and the Warrant Price shall be subject to adjustment
      from time to time as described herein.
    

    
      This Warrant is one of a series of Series G Warrants of like tenor
      issued by the Company pursuant to that certain Unit Purchase Agreement
      dated April 14, 2009, among the Company and the Investors named therein
      (the “Purchase Agreement”), and initially covering
      an aggregate of up to 10,000 shares of Common Stock (collectively, the “Company
      Warrants”).
    

    
      Section 1.  Registration.  The Company shall maintain
      books for the transfer and registration of the Warrant.  Upon the
      initial issuance of this Warrant, the Company shall issue and register
      the Warrant in the name of the Warrantholder.
    

    
      Section 2.  Transfers.  As provided herein, this
      Warrant may be transferred only pursuant to a registration statement
      filed under the Securities Act of 1933, as amended (the “Securities
      Act”), or an exemption from such registration.  Subject to such
      restrictions, the Company shall transfer this Warrant from time to time
      upon the books to be maintained by the Company for that purpose, upon
      surrender hereof for transfer, properly endorsed or accompanied by
      appropriate instructions for transfer and such other documents as may be
      reasonably required by the Company, including, if required by the
      Company, an opinion of its counsel to the effect that such transfer is
      exempt from the registration requirements of the Securities Act, to
      establish that such transfer is being made in accordance with the terms
      hereof, and a new Warrant shall be issued to the transferee and the
      surrendered Warrant shall be canceled by the Company.
    

    
      
        

        

      

      
        

        

        
          

        

      

      
        

        

      

    

    
      Section 3.  Exercise of Warrant.  
    

    
         (a)  Subject to the provisions hereof, the Warrantholder may exercise
      this Warrant, in whole or in part, at any time after the Initial
      Exercise Date and prior to its expiration upon surrender of the Warrant,
      together with delivery of a duly executed Warrant exercise form, in the
      form attached hereto as Appendix A (the “Exercise Agreement”)
      and payment by cash, certified check or wire transfer of funds, or
      pursuant to a cashless exercise pursuant to Section3(b) below, of the
      aggregate Warrant Price for that number of Warrant Shares then being
      purchased, to the Company during normal business hours on any business
      day at the Company’s principal executive offices (or such other office
      or agency of the Company as it may designate by notice to the
      Warrantholder).  The Warrant Shares so purchased shall be deemed to be
      issued to the Warrantholder or the Warrantholder’s designee, as the
      record owner of such shares, as of the close of business on the date on
      which this Warrant shall have been surrendered (or the date evidence of
      loss, theft or destruction thereof and security or indemnity
      satisfactory to the Company has been provided to the Company), the
      Warrant Price shall have been paid and the completed Exercise Agreement
      shall have been delivered.  Certificates for the Warrant Shares so
      purchased shall be delivered to the Warrantholder within a reasonable
      time, not exceeding three (3) business days, after this Warrant shall
      have been so exercised.  The certificates so delivered shall be in such
      denominations as may be requested by the Warrantholder and shall be
      registered in the name of the Warrantholder or such other name as shall
      be designated by the Warrantholder, as specified in the Exercise
      Agreement.  If this Warrant shall have been exercised only in part,
      then, unless this Warrant has expired, the Company shall, at its
      expense, at the time of delivery of such certificates, deliver to the
      Warrantholder a new Warrant representing the right to purchase the
      number of shares with respect to which this Warrant shall not then have
      been exercised.  As used herein, “business day” means a day, other than
      a Saturday or Sunday, on which banks in Houston, Texas are open for the
      general transaction of business.  Each exercise hereof shall constitute
      the re-affirmation by the Warrantholder that the representations and
      warranties contained in Section 5 of the Purchase Agreement are true and
      correct in all material respects with respect to the Warrantholder as of
      the time of such exercise.  Notwithstanding the foregoing, to effect the
      exercise of the Warrant hereunder, the Warrantholder shall not be
      required to physically surrender this Warrant to the Company unless the
      entire Warrant is exercised.  The Warrantholder and the Company shall
      maintain records showing the amount exercised and the dates of such
      exercise.  The Warrantholder and any assignee, by acceptance of this
      Warrant, acknowledge and agree that, by reason of the provision of the
      paragraph, following exercise of a portion of the Warrant, the number of
      Warrant Shares of this Warrant may be less than the amount stated on the
      face hereof.  
    

    
         (b)  Subject to the provisions hereof, the Warrantholder may effect
      one or more cashless exercises by surrendering Warrants to the Warrant
      Agent and giving written notice that the Warrantholder wishes to effect
      a cashless exercise by surrendering some Warrants without exercise, upon
      which the Company shall issue, or cause to be issued, to the
      Warrantholder up to the number of Warrant Shares determined as follows:
    

    
      
        

        

      

      
        
          2
        

        
          

        

      

      
        

        

      

    

    
      X         =         Y x (A-B)/A
    

    
      where:
    

    
      X         =         the maximum number of Warrant Shares that may be
      issued to the Warrantholder;
    

    
      Y         =         the number of Warrant Shares with respect to which
      the Warrant Certificates are being exercised;
    

    
      A         =         the Market Price as of the Date of Exercise; and
    

    
      B         =         the Exercise Price.
    

    
      “Market Price” of a share of Common Stock on any
      date shall mean, (i) if the shares of Common Stock are traded on the
      NASDAQ Stock Market, the last bid price reported on that date; (ii) if
      the shares of Common Stock are no longer quoted on the NASDAQ Stock
      Market and are listed on any other national securities exchange, the
      last sale price of the Common Stock reported by such exchange on that
      date; (iii) if the shares of Common Stock are not quoted on a any such
      market or listed on any such exchange and the shares of Common Stock are
      traded in the over-the-counter market, the last price reported on such
      day by the OTC Bulletin Board; (iv) if the shares of Common Stock are
      not quoted on a any such market, listed on any such exchange or quoted
      on the OTC Bulletin Board, then the last price quoted on such day in the
      over-the-counter market as reported by the National Quotation Bureau
      Incorporated (or any similar organization or agency succeeding its
      functions of reporting prices); or (v) if none of clauses (i)-(iv) are
      applicable, then as determined by mutual agreement of the Company and
      the Warrantholder; or if the Company and the Warrantholder are unable to
      agree on a Market Price, either party may submit the matter to
      arbitration as provided in Section 17.
    

    
      “Date of Exercise” means the date on which the
      Company has received from Warrantholder (i) the Warrant, and (ii) a
      written notice of election to exercise signed by Warrantholder and
      indicating the number of Warrant Shares to be purchased.
    

    
      This rights granted herein shall not in any way limit any other remedies
      that a Warrantholder may have under the Registration Rights Agreement
      (the “Registration Rights Agreement”) or in any
      other agreement or any other remedies that may be available pursuant to
      applicable law for breach by the Company of the Registration Rights
      Agreement.
    

    
      
        

        

      

      
        
          3
        

        
          

        

      

      
        

        

      

    

    
         (c)  Company’s Failure to Timely Deliver
      Securities.  If within three (3) Trading Days after the Company’s
      receipt of the facsimile copy of an Exercise Notice the Company shall
      fail to issue and deliver a certificate to the Warrantholder and
      register such shares of Common Stock on the Company’s share register or
      credit the Warrantholder’s balance account with the Depository Trust &
      Clearing Corporation for the number of shares of Common Stock to which
      the Warrantholder is entitled upon the Warrantholder’s exercise
      hereunder or pursuant to the Company’s obligation set forth in clause
      (ii) below, and if on or after such Trading Day the Warrantholder
      purchases (in an open market transaction or otherwise) shares of Common
      Stock to deliver in satisfaction of a sale by the Warrantholder of
      shares of Common Stock issuable upon such exercise that the
      Warrantholder anticipated receiving from the Company (a “Buy-In”),
      then the Company shall, within three (3) Business Days after the
      Warrantholder’s request and in the Warrantholder’s discretion, either
      (i) pay cash to the Warrantholder in an amount equal to the
      Warrantholder’s total purchase price (including brokerage commissions,
      if any) for the shares of Common Stock so purchased (the “Buy-In
      Price”), at which point the Company’s obligation to deliver such
      certificate (and to issue such shares of Common Stock) or credit such
      Warrantholder’s balance account with DTC shall terminate, or (ii)
      promptly honor its obligation to deliver to the Warrantholder a
      certificate or certificates representing such shares of Common Stock or
      credit such Warrantholder’s balance account with DTC and pay cash to the
      Warrantholder in an amount equal to the excess (if any) of the Buy-In
      Price over the product of (A) such number of shares of Common Stock,
      times (B) the Market Price on the date of exercise.
    

    
      Section 4.  Compliance with the Securities Act of 1933.
      This Warrant may only be exercised by the Warrantholder if the
      Warrantholder is an “accredited investor” as defined by Rule 501 of
      Regulation D.  The Company may cause the legend set forth on the first
      page of this Warrant to be set forth on each Warrant, and a similar
      legend on any security issued or issuable upon exercise of this Warrant,
      unless counsel for the Company is of the opinion as to any such security
      that such legend is unnecessary.
    

    
      Section 5.  Payment of Taxes.  The Company will pay any
      documentary stamp taxes attributable to the initial issuance of Warrant
      Shares issuable upon the exercise of the Warrant; provided, however,
      that the Company shall not be required to pay any tax or taxes which may
      be payable in respect of any transfer involved in the issuance or
      delivery of any certificates for Warrant Shares in a name other than
      that of the Warrantholder in respect of which such shares are issued,
      and in such case, the Company shall not be required to issue or deliver
      any certificate for Warrant Shares or any Warrant until the person
      requesting the same has paid to the Company the amount of such tax or
      has established to the Company’s reasonable satisfaction that such tax
      has been paid.  The Warrantholder shall be responsible for income taxes
      due under federal, state or other law, if any such tax is due.
    

    
      Section 6.  Mutilated or Missing Warrants.  In case
      this Warrant shall be mutilated, lost, stolen, or destroyed, the Company
      shall issue in exchange and substitution of and upon surrender and
      cancellation of the mutilated Warrant, or in lieu of and substitution
      for the Warrant lost, stolen or destroyed, a new Warrant of like tenor
      and for the purchase of a like number of Warrant Shares, but only upon
      receipt of evidence reasonably satisfactory to the Company of such loss,
      theft or destruction of the Warrant, and with respect to a lost, stolen
      or destroyed Warrant, reasonable indemnity or bond with respect thereto,
      if requested by the Company.
    

    
      Section 7.  Reservation of Common Stock.  At any time
      when this Warrant is exercisable, the Company shall at all applicable
      times keep reserved until issued (if necessary) as contemplated by this
      Section 7, out of the authorized and unissued shares of Common Stock, at
      least a number of shares of Common Stock equal to 120% of the number of
      shares of Common Stock as shall from time to time be necessary to effect
      the exercise of all of this Warrant then outstanding.  The Company
      agrees that all Warrant Shares issued upon due exercise of the Warrant
      shall be, at the time of delivery of the certificates for such Warrant
      Shares, duly authorized, validly issued, fully paid and non-assessable
      shares of Common Stock of the Company.
    

    
      
        

        

      

      
        
          4
        

        
          

        

      

      
        

        

      

    

    
      Section 8.  Adjustments.  
    

    
         (a)  If the Company shall, at any time or from time to time while
      this Warrant is outstanding, pay a dividend or make a distribution on
      its Common Stock in shares of Common Stock, subdivide its outstanding
      shares of Common Stock into a greater number of shares or combine its
      outstanding shares of Common Stock into a smaller number of shares or
      issue by reclassification of its outstanding shares of Common Stock any
      shares of its capital stock (including any such reclassification in
      connection with a consolidation or merger in which the Company is the
      continuing corporation), then (i) the Warrant Price in effect
      immediately prior to the date on which such change shall become
      effective shall be adjusted by multiplying such Warrant Price by a
      fraction, the numerator of which shall be the number of shares of Common
      Stock outstanding immediately prior to such change and the denominator
      of which shall be the number of shares of Common Stock outstanding
      immediately after giving effect to such change and (ii) the number of
      Warrant Shares purchasable upon exercise of this Warrant shall be
      adjusted by multiplying the number of Warrant Shares purchasable upon
      exercise of this Warrant immediately prior to the date on which such
      change shall become effective by a fraction, the numerator of which is
      shall be the Warrant Price in effect immediately prior to the date on
      which such change shall become effective and the denominator of which
      shall be the Warrant Price in effect immediately after giving effect to
      such change, calculated in accordance with clause (i) above.  Such
      adjustments shall be made successively whenever any event listed above
      shall occur.
    

    
         (b)  If any capital reorganization, reclassification of the capital
      stock of the Company, consolidation or merger of the Company with
      another corporation in which the Company is not the survivor, or sale,
      transfer or other disposition of all or substantially all of the
      Company’s assets to another corporation shall be effected, then, as a
      condition of such reorganization, reclassification, consolidation,
      merger, sale, transfer or other disposition, lawful and adequate
      provision shall be made whereby each Warrantholder shall thereafter have
      the right to purchase and receive upon the basis and upon the terms and
      conditions herein specified and in lieu of the Warrant Shares
      immediately theretofore issuable upon exercise of the Warrant, such
      shares of stock, securities or assets as would have been issuable or
      payable with respect to or in exchange for a number of Warrant Shares
      equal to the number of Warrant Shares immediately theretofore issuable
      upon exercise of the Warrant, had such reorganization, reclassification,
      consolidation, merger, sale, transfer or other disposition not taken
      place, and in any such case appropriate provision shall be made with
      respect to the rights and interests of each Warrantholder to the end
      that the provisions hereof (including, without limitation, provision for
      adjustment of the Warrant Price) shall thereafter be applicable, as
      nearly equivalent as may be practicable in relation to any shares of
      stock, securities or assets thereafter deliverable upon the exercise
      hereof.  The Company shall not effect any such consolidation, merger,
      sale, transfer or other disposition unless prior to or simultaneously
      with the consummation thereof the successor corporation (if other than
      the Company) resulting from such consolidation or merger, or the
      corporation purchasing or otherwise acquiring such assets or other
      appropriate corporation or entity shall assume the obligation to deliver
      to the Warrantholder, at the last address of the Warrantholder appearing
      on the books of the Company, such shares of stock, securities or assets
      as, in accordance with the foregoing provisions, the Warrantholder may
      be entitled to purchase, and the other obligations under this
      Warrant.  The provisions of this paragraph (b) shall similarly apply to
      successive reorganizations, reclassifications, consolidations, mergers,
      sales, transfers or other dispositions.
    

    
      
        

        

      

      
        
          5
        

        
          

        

      

      
        

        

      

    

    
         (c)  In case the Company shall fix a payment date for the making of a
      distribution to all holders of Common Stock (including any such
      distribution made in connection with a consolidation or merger in which
      the Company is the continuing corporation) of evidences of indebtedness
      or assets (other than cash dividends or cash distributions payable out
      of consolidated earnings or earned surplus or dividends or distributions
      referred to in Section 8(a)), or subscription rights or warrants, the
      Warrant Price to be in effect after such payment date shall be
      determined by multiplying the Warrant Price in effect immediately prior
      to such payment date by a fraction, the numerator of which shall be the
      total number of shares of Common Stock outstanding multiplied by the
      Market Price per share of Common Stock immediately prior to such payment
      date, less the fair market value (as determined by the Company’s Board
      of Directors in good faith) of said assets or evidences of indebtedness
      so distributed, or of such subscription rights or warrants, and the
      denominator of which shall be the total number of shares of Common Stock
      outstanding multiplied by such Market Price per share of Common Stock
      immediately prior to such payment date.  
    

    
         (d)  An adjustment to the Warrant Price shall become effective
      immediately after the payment date in the case of each dividend or
      distribution and immediately after the effective date of each other
      event which requires an adjustment.
    

    
         (e)  In the event that, as a result of an adjustment made pursuant to
      this Section 8, the Warrantholder shall become entitled to receive any
      shares of capital stock of the Company other than shares of Common
      Stock, the number of such other shares so receivable upon exercise of
      this Warrant shall be subject thereafter to adjustment from time to time
      in a manner and on terms as nearly equivalent as practicable to the
      provisions with respect to the Warrant Shares contained in this Warrant.
    

    
         (f)  To the extent permitted by applicable law and the listing
      requirements of any stock market or exchange on which the Common Stock
      is then listed, the Company from time to time may decrease the Warrant
      Price by any amount for any period of time if the period is at least
      twenty (20) days, the decrease is irrevocable during the period and the
      Board shall have made a determination that such decrease would be in the
      best interests of the Company, which determination shall be conclusive provided
      however, that the Warrant Price may not be decreased below the
      Market Price on the date of the execution of Purchase
      Agreement.  Whenever the Warrant Price is decreased pursuant to the
      preceding sentence, the Company shall provide written notice thereof to
      the Warrantholder at least five (5) days prior to the date the decreased
      Warrant Price takes effect, and such notice shall state the decreased
      Warrant Price and the period during which it will be in
      effect.  Notwithstanding the foregoing, the Company shall treat all
      holders of the Company Warrants equally.
    

    
      
        

        

      

      
        
          6
        

        
          

        

      

      
        

        

      

    

    
      Section 9.  Fractional Interest.  The Company shall not
      be required to issue fractions of Warrant Shares upon the exercise of
      this Warrant.  If any fractional share of Common Stock would, except for
      the provisions of the first sentence of this Section 9, be deliverable
      upon such exercise, the Company, in lieu of delivering such fractional
      share, shall pay to the exercising Warrantholder an amount in cash equal
      to the Market Price (determined in accordance with Section 3(b)) of such
      fractional share of Common Stock on the date of exercise.
    

    
      Section 10.  Benefits.  Nothing in this Warrant shall
      be construed to give any person, firm or corporation (other than the
      Company and the Warrantholder) any legal or equitable right, remedy or
      claim, it being agreed that this Warrant shall be for the sole and
      exclusive benefit of the Company and the Warrantholder.
    

    
      Section 11.  Notices to Warrantholder.  Upon the
      happening of any event requiring an adjustment of the Warrant Price, the
      Company shall promptly give written notice thereof to the Warrantholder
      at the address appearing in the records of the Company, stating the
      adjusted Warrant Price and the adjusted number of Warrant Shares
      resulting from such event and setting forth in reasonable detail the
      method of calculation and the facts upon which such calculation is
      based.  Failure to give such notice to the Warrantholder or any defect
      therein shall not affect the legality or validity of the subject
      adjustment.
    

    
      Section 12.  Identity of Transfer Agent.  The Transfer
      Agent for the Common Stock is Continental Stock Transfer & Trust, 17
      Battery Place, New York, New York 10004.  Upon the appointment of any
      subsequent transfer agent for the Common Stock or other shares of the
      Company’s capital stock issuable upon the exercise of the rights of
      purchase represented by the Warrant, the Company will mail to the
      Warrantholder a statement setting forth the name and address of such
      transfer agent.
    

    
      Section 13.  Notices.  Unless otherwise provided, any
      notice required or permitted under this Warrant shall be given in
      writing and shall be deemed effectively given and received as
      hereinafter described (i) if given by personal delivery, then such
      notice shall be deemed received upon such delivery, (ii) if given by
      telex or facsimile, then such notice shall be deemed received upon
      receipt of confirmation of complete transmittal, (iii) if given by
      certified mail return receipt requested, then such notice shall be
      deemed received upon the day such return receipt is signed, and (iv) if
      given by an internationally recognized overnight air courier, then such
      notice shall be deemed given one business day after delivery to such
      carrier.  Copies of such notices shall also be transmitted by email to
      the email address provided for on the signature page of the Purchase
      Agreement.  All notices shall be addressed as follows: if to the
      Warrantholder, at its address as set forth in the Company’s books and
      records and, if to the Company, at the address as follows, or at such
      other address as the Warrantholder or the Company may designate by ten
      days’ advance written notice to the other:
    

    
      
        

        

      

      
        
          7
        

        
          

        

      

      
        

        

      

    

    
      If to the Company:
    

    
      Opexa Therapeutics, Inc.
2635 Crescent Ridge Drive
The Woodlands,
      Texas 77381
Attention:  President
Fax:  (281) 872-8585
    

    
      With a copy to:
    

    
      Vinson & Elkins, LLP
First City Tower, 1001 Fannin Street, Suite
      2500
Houston, Texas 77002
Attention:  Michael C. Blaney
Fax:  (713)
      758-2222
    

    
      Section 14.  Registration Rights.  The initial
      Warrantholder (and its applicable assignees as provided in the
      Registration Rights Agreement) is entitled to the benefit of certain
      registration rights with respect to the shares of Common Stock issuable
      upon the exercise of this Warrant as provided in the Registration Rights
      Agreement.
    

    
      Section 15.  Successors.  All the covenants and
      provisions hereof by or for the benefit of the Warrantholder shall bind
      and inure to the benefit of its respective successors and assigns
      hereunder.
    

    
      Section 16.  Governing Law; Consent to Jurisdiction; Waiver
      of Jury Trial.  This Warrant shall be governed by, and construed in
      accordance with, the internal laws of the State of Texas, without
      reference to the choice of law provisions thereof.  The Company and, by
      accepting this Warrant, the Warrantholder, each irrevocably submits to
      the exclusive jurisdiction of the courts of the State of Texas located
      in Harris County and the United States District Court for the Southern
      District of Texas [and the courts of the State of New York, Borough of
      Manhattan and the United States District Court for the Southern District
      of New York] for the purpose of any suit, action, proceeding or judgment
      relating to or arising out of this Warrant and the transactions
      contemplated hereby.  Service of process in connection with any such
      suit, action or proceeding may be served on each party hereto anywhere
      in the world by the same methods as are specified for the giving of
      notices under this Warrant.  The Company and, by accepting this Warrant,
      the Warrantholder, each irrevocably consents to the jurisdiction of any
      such court in any such suit, action or proceeding and to the laying of
      venue in such court.  The Company and, by accepting this Warrant, the
      Warrantholder, each irrevocably waives any objection to the laying of
      venue of any such suit, action or proceeding brought in such courts and
      irrevocably waives any claim that any such suit, action or proceeding
      brought in any such court has been brought in an inconvenient forum.  EACH
      OF THE COMPANY AND, BY ITS ACCEPTANCE HEREOF, THE WARRANTHOLDER HEREBY
      WAIVES ANY RIGHT TO REQUEST A TRIAL BY JURY IN ANY LITIGATION WITH
      RESPECT TO THIS WARRANT AND REPRESENTS THAT COUNSEL HAS BEEN CONSULTED
      SPECIFICALLY AS TO THIS WAIVER.
    

    
      
        

        

      

      
        
          8
        

        
          

        

      

      
        

        

      

    

    
      Section 17.  Dispute Resolution.  In the case of a
      dispute as to the determination of the Market Price, the Company shall
      submit the disputed determinations via facsimile to the
      Warrantholder.  If the Warrantholder and the Company are unable to agree
      upon such determination of the Market Price within three business days
      of such disputed determination being submitted to the Warrantholder,
      then the Company shall, within two business days, submit via facsimile
      the disputed determination of the Market Price to an independent,
      reputable investment bank selected by the Company and approved by the
      Warrantholder.  The Company shall cause at its expense the investment
      bank to perform the determinations and notify the Company and the
      Warrantholder of the results no later than ten business days from the
      time it receives the disputed determinations or calculations.  Such
      investment bank's determination shall be binding upon all parties absent
      demonstrable error.
    

    
      Section 18.  No Rights as Stockholder.  Prior to the
      exercise of this Warrant, the Warrantholder shall not have or exercise
      any rights as a stockholder of the Company by virtue of its ownership of
      this Warrant.
    

    
      Section 19.  Amendment; Waiver.  Any term of this
      Warrant may be amended or waived (including the adjustment provisions
      included in Section 8 of this Warrant) upon the written consent of the
      Company and the holders of Series G Warrants representing at least 50%
      of the number of shares of Common Stock then subject to all outstanding
      Series G Warrants (the “Majority Holders”); provided,
      that (x) any such amendment or waiver must apply to all Series G
      Warrants; and (y) the number of Warrant Shares subject to this Warrant,
      the Warrant Price and the Expiration Date may not be amended, and the
      right to exercise this Warrant may not be altered or waived, without the
      written consent of the Warrantholder.
    

    
      Section 20.  Remedies; Other Obligations; Breaches and
      Injunctive Relief.  The remedies provided in this Warrant shall be
      cumulative and in addition to all other remedies available under this
      Warrant and the other Transaction Documents, at law or in equity
      (including a decree of specific performance and/or other injunctive
      relief), and nothing herein shall limit the right of the Warrantholder
      right to pursue actual damages for any failure by the Company to comply
      with the terms of this Warrant.  The Company acknowledges that a breach
      by it of its obligations hereunder will cause irreparable harm to the
      Warrantholder and that the remedy at law for any such breach may be
      inadequate.  The Company therefore agrees that, in the event of any such
      breach or threatened breach, the Warrantholder shall be entitled, in
      addition to all other available remedies, an injunction restraining any
      breach, without the necessity of showing economic loss and without any
      bond or other security being required.
    

    
      Section 21.  Section Headings.  The section headings in
      this Warrant are for the convenience of the Company and the
      Warrantholder and in no way alter, modify, amend, limit or restrict the
      provisions hereof.
    

    
      [Signature Page Follows]
    

    
      
        

        

      

      
        
          9
        

        
          

        

      

      
        

        

      

    

    

    

    
      IN WITNESS WHEREOF, the Company has caused this Warrant to be duly
      executed, as of the 14th day of April, 2009.
    

    
    	
           
        	
          OPEXA THERAPEUTICS, INC.
        
	

        	

        	
           
        
	

        	

        	
           
        
	

        	

        	
           
        
	
          
             
          

        	
          
            By:
          

        	
          /S/ NEIL K. WARMA
        
	

        	

        	
          Neil K. Warma
        
	

        	

        	
          President and Chief Executive Officer
        

    

    

    

    
      

      

      

      Signature Page to
Series G Warrant to Purchase _____ Shares
      of
Common Stock, Par Value $0.50 Per Share
    

    
      
        

        

      

      
        

        

        
          

        

      

      
        

        

      

    

    

    

    
      APPENDIX A
    

    
      OPEXA THERAPEUTICS, INC.
WARRANT EXERCISE FORM
    

    
      To Opexa Therapeutics, Inc.:
    

    
      The undersigned hereby irrevocably elects to exercise the right of
      purchase represented by the within Warrant (“Warrant”)
      for, and to purchase thereunder by the payment of the Warrant Price and
      surrender of the Warrant, _______________ shares of Common Stock (“Warrant
      Shares”) provided for therein, and requests that certificates
      for the Warrant Shares be issued as follows:
    

    
    	
           
        
	
          Name
        
	
           
        
	
           
        
	
          Address
        
	
           
        
	
          Federal Tax ID or Social Security No.
        

    

    
      and delivered by (certified mail to the above address, or
      (electronically (provide DWAC Instructions:________________), or (other
      (specify): ___________________________).  
    

    
      and, if the number of Warrant Shares shall not be all the Warrant Shares
      purchasable upon exercise of the Warrant, that a new Warrant for the
      balance of the Warrant Shares purchasable upon exercise of this Warrant
      be registered in the name of the undersigned Warrantholder or the
      undersigned’s Assignee as below indicated and delivered to the address
      stated below.
    

    
    	
          
            Note: The signature must correspond with
the name of the
            Warrantholder as written on
the first page of the Warrant in
            every
particular, without alteration or enlargement
or any
            change whatever, unless the Warrant
has been assigned.
          

        	
          
            Signature:
          

          
             
          

        
	

        	
           
        
	

        	
           
        
	

        	
          
            Name (please print)
          

        
	

        	
           
        
	

        	
           
        
	

        	
           
        
	

        	
          
            Address
          

        
	

        	
           
        
	

        	
           
        
	

        	
          
            Federal Identification or Social Security No.
          

        
	

        	
           
        
	

        	
          Assignee:
        
	

        	
           
        
	

        	
           
        

    

    

    

    
      

      

      

      Appendix A
Warrant Exercise Form

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