Exhibit 4.2

    

     

      

    
      Execution Version

       

      

      REGISTRATION RIGHTS AGREEMENT

       

       REGISTRATION RIGHTS AGREEMENT (this “Agreement”),
          dated as of June 17, 2020, by and among Rexahn Pharmaceuticals, Inc., a Delaware corporation, with headquarters located at 15245 Shady Grove Road, Suite 455, Rockville, MD 20850 to be renamed “Ocuphire Pharma, Inc.” pursuant to the Merger
          Agreement (as defined below) (the “Company”), and the investors listed on the Schedule of Buyers attached hereto (each, a “Buyer” and collectively, the “Buyers”).

       

       WHEREAS:

       

       A.         In connection with the Securities Purchase Agreement (the “Securities Purchase Agreement”) by and among Ocuphire Pharma, Inc., a Delaware
        corporation (“Ocuphire Private Company”), the Company and the Buyers of even date herewith, upon the terms and subject to the conditions of the Securities Purchase Agreement, (i) Ocuphire Private Company has
        agreed to issue to each Buyer shares of common stock, $0.0001 par value per share, of Ocuphire Private Company and (ii) the Company has agreed to issue Series A Warrants and Series B Warrants (each as defined below and collectively, the “Warrants”) which each will be exercisable to purchase shares of the Company’s common stock, par value $0.0001 per share (the “Common Stock”) (as exercised, collectively,
        the “Warrant Shares”) in accordance with the terms of the Warrants.

       

       B.         In accordance with the terms of the Securities Purchase Agreement, provided that the transactions contemplated by that certain Agreement and Plan of Merger and Reorganization among the
        Company, Razor Merger Sub, Inc., a Delaware corporation and wholly owned subsidiary of the Company and Ocuphire Private Company, dated as of June 17, 2020 (the “Merger Agreement”) are consummated, the Company
        has agreed to provide certain registration rights under the Securities Act of 1933, as amended, and the rules and regulations thereunder, or any similar successor statute (collectively, the “1933 Act”), and
        applicable state securities laws.

       

       NOW, THEREFORE, in consideration of the premises and the mutual covenants contained herein
          and other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the Company and each of the Buyers hereby agree as follows:

       

       1.           Definitions.

        

      

      Capitalized terms used herein and not otherwise defined herein shall have the respective meanings set forth in the Securities Purchase Agreement. As used in this Agreement, the following terms
        shall have the following meanings:

       

      

      (a)           “Additional Effective Date” means the date an Additional Registration Statement is declared effective by the SEC.

       

      (b)         “Additional Effectiveness Deadline” means the date which is the earlier of (i) in the event that the Additional Registration Statement (x) is
        not subject to a full review by the SEC, the date which is thirty (30) Trading Days after the earlier of the applicable Additional Filing Date and the Additional Filing Deadline or (y) is subject to a full review by the SEC, the date which is sixty
        (60) Trading Days after the earlier of the applicable Additional Filing Date and the Additional Filing Deadline and (ii) the fifth (5th) Business Day after the date the Company is notified (orally or in writing, whichever is earlier) by the SEC
        that such Additional Registration Statement will not be reviewed or will not be subject to further review; provided, however, that if the Additional Effectiveness Deadline falls on a Saturday, Sunday or other day that the SEC is
        closed for business, the Additional Effectiveness Deadline shall be extended to the next Business Day on which the SEC is open for business.

       

      

      
        
          


      

      
      (c)           “Additional Filing Date” means the date on which an Additional Registration Statement is filed with the SEC.

       

      (d)         “Additional Filing Deadline” means if Cutback Shares are required to be included in any Additional Registration Statement, the later of (i) the
        date sixty (60) days after the date substantially all of the Registrable Securities registered under the immediately preceding Registration Statement are sold and (ii) the date six (6) months from the Initial Effective Date, the most recent
        Subsequent Effective Date or the most recent Additional Effective Date, as applicable.

       

      (e)          “Additional Registrable Securities” means, (i) any Cutback Shares not previously included on a Registration Statement, and (ii) any capital
        stock of the Company issued or issuable with respect to the Series A Warrants, the Series B Warrants, the Series A Warrant Shares, the Series B Warrant Shares or the Cutback Shares, as applicable, as a result of any stock split, stock dividend,
        recapitalization, exchange or similar event or otherwise, without regard to any limitations on exercise of the Warrants.

       

      (f)           “Additional Registration Statement” means a registration statement or registration statements of the Company filed under the 1933 Act covering
        the resale any Additional Registrable Securities.

       

      (g)           “Additional Required Registration Amount” means any Cutback Shares not previously included on a Registration Statement, all subject to
        adjustment as provided in Section 2(g), without regard to any limitations on the exercise of the Warrants.

       

      (h)          “Business Day” means any day other than Saturday, Sunday or any other day on which commercial banks in the City of New York are authorized or
        required by law to remain closed.

       

      (i)            “Closing Date” shall have the meaning set forth in the Securities Purchase Agreement.

        

      

      (j)           “Cutback Shares” means any of the Initial Required Registration Amount, the Subsequent Required
        Registration Amount and/or the Additional Required Registration Amount of Registrable Securities which the SEC will not allow to be included in a Registration Statement as a result of a limitation on the maximum number of shares of Common Stock of
        the Company permitted to be registered by the staff of the SEC pursuant to Rule 415.  For the purpose of determining the Cutback Shares, in order to determine any applicable Required Registration Amount, unless an Investor gives written notice to
        the Company to the contrary with respect to the allocation of its Cutback Shares, first the Series A Warrant Shares shall be excluded on a pro rata basis among the Investors until all of the Series A Warrant Shares have been excluded and second the
        Series B Warrant Shares shall be excluded on a pro rata basis among the Investors until all of the Series B Warrant Shares have been excluded.

       

      
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      (k)           “Designee” means Altium Capital Management, LP.

       

      (l)            “effective” and “effectiveness” refer to a Registration Statement that has been declared effective by
        the SEC and is available for the resale of the Registrable Securities required to be covered thereby.

       

      (m)         “Effective Date” means the Initial Effective Date, each Subsequent Effective Date and/or each Additional Effective Date, as applicable.

       

      (n)        “Effectiveness Deadline” means the Initial Effectiveness Deadline, each Subsequent Effectiveness Deadline and/or each Additional Effectiveness
        Deadline, as applicable.

       

      (o)        “Eligible Market” means the Principal Market, the NYSE American, The Nasdaq Global Select Market, The Nasdaq Global Market or The New York Stock
        Exchange, Inc.

       

      (p)           “End Reset Date” shall have the meaning ascribed to such term in the Series B Warrants.

        

      

      (q)           “Filing Deadline” means the Initial Filing Deadline, each Subsequent Filing Deadline and/or each Additional Filing Deadline, as applicable.

       

      (r)            “Initial Effective Date” means the date that the Initial Registration Statement has been declared effective by the SEC.

       

      (s)           “Initial Effectiveness Deadline” means the date which is the earlier of (x) (i) in the event that
        the Initial Registration Statement is not subject to a full review by the SEC, forty five (45) Trading Days after the Closing Date or (ii) in the event that the Initial Registration Statement is subject to a full review by the SEC, seventy five
        (75) Trading Days after the Closing Date and (y) the fifth (5th) Business Day after the date the Company is notified (orally or in writing, whichever is earlier) by the SEC that such Initial Registration Statement will not be reviewed or will not
        be subject to further review; provided, however, that if the Initial Effectiveness Deadline falls on a Saturday, Sunday or other day that the SEC is closed for business, the Initial Effectiveness Deadline shall be extended to the
        next Business Day on which the SEC is open for business.

       

      (t)            “Initial Filing Deadline” means the date which is fifteen (15) Trading Days after the Closing Date.

       

      (u)           “Initial Registrable Securities” means (i) the Series A Warrant Shares issued or issuable upon exercise of the Series A Warrants, (ii) the
        Series B Warrant Shares issued or issuable upon exercise of the Series B Warrants and (iii) any capital stock of the Company issued or issuable with respect to the Series A Warrant Shares, the Series A Warrants, the Series B Warrant Shares or the
        Series B Warrants, in each case as a result of any stock split, stock dividend, recapitalization, exchange or similar event or otherwise, without regard to any limitations on the exercise of the Series A Warrants and/or the Series B Warrants.

       

      
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      (v)          “Initial Registration Statement” means a registration statement or registration statements of the Company filed under the 1933 Act covering the
        resale of Initial Registrable Securities.

       

      (w)         “Initial Required Registration Amount” means the number of shares of Common Stock issued and issuable pursuant to the Series A Warrants and the
        Series B Warrants equal to the greater of (A) the sum of (x) 135% of the number of Series A Warrant Shares issued and issuable pursuant to the Series A Warrants determined in accordance with Section 2(d) of the Series A Warrants assuming a Reset
        Price (as defined in the Series A Warrants) equal to the Reset Floor Price without giving effect to any limitation on exercise set forth therein and (y) 100% of the number of Series B Warrant Shares issued and issuable pursuant to the Series B
        Warrants assuming that the Maximum Eligibility Number (as defined in the Series B Warrant) is determined based on a Reset Price (as defined in the Series B Warrants) equal to the Reset Floor Price without giving effect to any limitation on exercise
        set forth therein and (B) the sum of (x) 135% of the number of shares of Common Stock issuable upon exercise of the Series A Warrants without giving effect to any limitation on exercise set forth in the Series A Warrants and (y) 100% of the number
        of shares of Common Stock issuable upon exercise of the Series B Warrants without giving effect to any limitation on exercise set forth in the Series B Warrants, calculated as of the Trading Day immediately preceding the applicable date of
        determination and all subject to adjustment as provided in Section 2(g).

       

      (x)          “Investor” means a Buyer or any transferee or assignee thereof to whom a Buyer assigns its rights under this Agreement and who agrees to become
        bound by the provisions of this Agreement in accordance with Section 9 and any transferee or assignee thereof to whom a transferee or assignee assigns its rights under this Agreement and who agrees to become bound by the provisions of this
        Agreement in accordance with Section 9.

       

      (y)           “Person” means an individual, a limited liability company, a partnership, a joint venture, a corporation, a trust, an unincorporated
        organization and a government or any department or agency thereof.

       

      (z)           “Principal Market” means The Nasdaq Capital Market.

       

      (aa)       “register,” “registered,” and “registration” refer to a
        registration effected by preparing and filing one or more Registration Statements (as defined below) in compliance with the 1933 Act and pursuant to Rule 415, and the declaration or ordering of effectiveness of such Registration Statement(s) by the
        SEC.

       

      (bb)       “Registrable Securities” means the Initial Registrable Securities, the Subsequent Registrable Securities and/or the Additional Registrable
        Securities, as applicable.

       

      (cc)       “Registration Statement” means the Initial Registration Statement, the Subsequent Registration Statement(s) and/or the Additional Registration
        Statement(s), as applicable.

       

      
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      (dd)         “Required Holders” means the holders of at least a majority of the Registrable Securities and shall include the Designee so long as the
        Designee or any of its affiliates holds any Warrants or Registrable Securities.

       

      (ee)         “Required Registration Amount” means either the Initial Required Registration Amount, the Subsequent
        Required Registration Amount and/or the Additional Required Registration Amount, as applicable.

       

      (ff)          “Reservation Date” shall have the meaning ascribed to such term in the Warrants.

       

      (gg)        “Reset Floor Price” shall have the meaning ascribed to such term in the Warrants.

       

      (hh)       “Rule 415” means Rule 415 promulgated under the 1933 Act or any successor rule providing for offering securities on a continuous or delayed
        basis.

       

      (ii)          “SEC” means the United States Securities and Exchange Commission.

       

      (jj)          “Series A Warrants” shall have the meaning set forth in the Securities Purchase Agreement.

       

      (kk)         “Series A Warrant Shares” shall have the meaning set forth in the Securities Purchase Agreement.

       

      (ll)           “Series B Warrants” shall have the meaning set forth in the Securities Purchase Agreement.

       

      (mm)       “Series B Warrant Shares” shall have the meaning set forth in the Securities Purchase Agreement.

       

      (nn)         “Subsequent Effective Date” means the date that a Subsequent Registration Statement has been declared
        effective by the SEC.

       

      (oo)         “Subsequent Effectiveness Deadline” means the date which is the earlier of (x) the sixtieth (60th) day after the earlier of the applicable Subsequent Filing Date and the applicable Subsequent Filing Deadline and (y) the fifth (5th) Business Day after the date the
        Company is notified (orally or in writing, whichever is earlier) by the SEC that such Subsequent Registration Statement will not be reviewed or will not be subject to further review; provided, however,
        that if a Subsequent Effectiveness Deadline falls on a Saturday, Sunday or other day that the SEC is closed for business, the Subsequent Effectiveness Deadline shall be
        extended to the next Business Day on which the SEC is open for business.

       

      (pp)         “Subsequent Filing Date” means the date on which the applicable Subsequent Registration Statement is
        filed with the SEC.

       

      
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      (qq)         “Subsequent Filing Deadline” means the date which is fifteen (15) calendar days after each End Reset Date.

       

      (rr)         “Subsequent Registrable Securities” means (i) the Series A Warrant Shares issued or issuable upon exercise of the Series A Warrants to the
        extent such Series A Warrant Shares were not included in all Registration Statements previously declared effective hereunder, (ii) the Series B Warrant Shares issued or issuable upon exercise of the Series B Warrants to the extent such Series B
        Warrant Shares were not included in all Registration Statements previously declared effective hereunder and (iii) any capital stock of the Company issued or issuable with respect to the Series A Warrant Shares, Series B Warrant Shares, Series A
        Warrants or Series B Warrants to the extent such capital stock was not included in all Registration Statements previously declared effective hereunder, in each case as a result of any stock split, stock dividend, recapitalization, exchange or
        similar event or otherwise, without regard to any limitations on the exercise of the Warrants.

       

      (ss)          “Subsequent Registration Statement” means a registration statement or registration statements of the Company filed under the 1933 Act covering
        the resale of Subsequent Registrable Securities.

       

      (tt)          “Subsequent Required Registration Amount” means the number of shares of Common Stock issued and issuable pursuant to the Series A Warrants and
        the Series B Warrants equal the greater of (A) the sum of (x) 135% of the number of Series A Warrant Shares issued and issuable pursuant to the Series A Warrants determined in accordance with Section 2(d) of the Series A Warrants assuming a Reset
        Price (as defined in the Series A Warrants) equal to Reset Floor Price without giving effect to any limitation on exercise set forth therein to the extent such Series A Warrant Shares were not included in all Registration Statements previously
        declared effective hereunder and (y) 100% of the number of Series B Warrant Shares issued and issuable pursuant to the Series B Warrants assuming that the Maximum Eligibility Number (as defined in the Series B Warrant) is determined based on a
        Reset Price (as defined in the Series B Warrants) equal to the Reset Floor Price without giving effect to any limitation on exercise set forth therein to the extent such Series B Warrant Shares were not included in all Registration Statements
        previously declared effective hereunder and (B) the sum of (x) 135% of the number of shares of Common Stock issuable upon exercise of the Series A Warrants without giving effect to any limitation on exercise set forth in the Series A Warrants to
        the extent such Series A Warrant Shares were not included in all Registration Statements previously declared effective hereunder and (y) 100% of the number of shares of Common Stock issuable upon exercise of the Series B Warrants without giving
        effect to any limitation on exercise set forth in the Series B Warrants to the extent such Series B Warrant Shares were not included in all Registration Statements previously declared effective hereunder, calculated as of the Trading Day
        immediately preceding the applicable date of determination and all subject to adjustment as provided in Section 2(g).

       

      (uu)        “Trading Day” means any day on which the Common Stock is traded on the Principal Market, or, if the Principal Market is not the principal
        trading market for the Common Stock on such day, then on the principal securities exchange or securities market on which the Common Stock is then traded.

       

      

      
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       2.          Registration.

       

      (a)           Initial Mandatory Registration.  The Company shall prepare, and, as soon as practicable but in no event later than the Initial Filing Deadline, file with the SEC the Initial
        Registration Statement on Form S-3 covering the resale of all of the Initial Registrable Securities.  In the event that Form S-3 is unavailable for such a registration, the Company shall use such other form as is available for such a registration
        on another appropriate form reasonably acceptable to the Required Holders, subject to the provisions of Section 2(f).  The Initial Registration Statement prepared pursuant hereto shall register for resale at least the number of shares of Common
        Stock equal to the Initial Required Registration Amount determined as of the date the Initial Registration Statement is initially filed with the SEC, subject to adjustment as provided in Section 2(g).  The Initial Registration Statement shall
        contain (except if otherwise directed by the Required Holders) the “Plan of Distribution” and “Selling Stockholders” sections in substantially the form attached hereto as Exhibit B.  The Company shall use its commercially
        reasonable efforts to have the Initial Registration Statement declared effective by the SEC as soon as practicable, but in no event later than the Initial Effectiveness Deadline.  By 9:30 a.m. New York time on the Business Day following the Initial
        Effective Date, the Company shall file with the SEC in accordance with Rule 424 under the 1933 Act the final prospectus to be used in connection with sales pursuant to such Initial Registration Statement.

       

      (b)         Subsequent Mandatory Registrations.  The Company shall prepare, and, as soon as practicable but in no event later than the Subsequent Filing Deadline, file with the SEC a
        Subsequent Registration Statement on Form S-3 covering the resale of all of the Subsequent Registrable Securities not previously registered on a Subsequent Registration Statement hereunder.  In the event that Form S-3 is unavailable for such a
        registration, the Company shall use such other form as is available for such a registration on another appropriate form reasonably acceptable to the Required Holders, subject to the provisions of Section 2(f).  Each Subsequent Registration
        Statement prepared pursuant hereto shall register for resale at least that number of shares of Common Stock equal to the Subsequent Required Registration Amount determined as of the date such Subsequent Registration Statement is initially filed
        with the SEC, subject to adjustment as provided in Section 2(g).  Each Subsequent Registration Statement shall contain (except if otherwise directed by the Required Holders) the “Plan of Distribution” and “Selling Stockholders”
        sections in substantially the form attached hereto as Exhibit B.  The Company shall use its commercially reasonable efforts to have each Subsequent Registration Statement declared effective by the SEC as soon as practicable, but in no event
        later than the Subsequent Effectiveness Deadline.  By 9:30 a.m. New York time on the Business Day following the Subsequent Effective Date, the Company shall file with the SEC in accordance with Rule 424 under the 1933 Act the final prospectus to be
        used in connection with sales pursuant to such Subsequent Registration Statement.

       

      
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      (c)         Additional Mandatory Registrations.  The Company shall prepare, and, as soon as practicable but in no event later than the Additional Filing Deadline, file with the SEC an
        Additional Registration Statement on Form S-3 covering the resale of all of the Additional Registrable Securities not previously registered on an Additional Registration Statement hereunder.  To the extent the staff of the SEC does not permit the
        Additional Required Registration Amount to be registered on an Additional Registration Statement, the Company shall file Additional Registration Statements successively trying to register on each such Additional Registration Statement the maximum
        number of remaining Additional Registrable Securities until the Additional Required Registration Amount has been registered with the SEC.  In the event that Form S-3 is unavailable for such a registration, the Company shall use such other form as
        is available for such a registration on another appropriate form reasonably acceptable to the Required Holders, subject to the provisions of Section 2(f).  Each Additional Registration Statement prepared pursuant hereto shall register for resale at
        least that number of shares of Common Stock equal to the Additional Required Registration Amount determined as of the date such Additional Registration Statement is initially filed with the SEC, subject to adjustment as provided in Section 2(g). 
        Each Additional Registration Statement shall contain (except if otherwise directed by the Required Holders) the “Plan of Distribution” and “Selling Stockholders” sections in substantially the form attached hereto as Exhibit B. 



        The Company shall use its commercially reasonable efforts to have each Additional Registration Statement declared effective by the SEC as soon as practicable, but in no event later than the Additional Effectiveness Deadline.  By 9:30 a.m. New York
        time on the Business Day following the Additional Effective Date, the Company shall file with the SEC in accordance with Rule 424 under the 1933 Act the final prospectus to be used in connection with sales pursuant to such Additional Registration
        Statement.

       

      (d)         Allocation of Registrable Securities.  The initial number of Registrable Securities included in any Registration Statement and any increase or decrease in the number of
        Registrable Securities included therein shall be allocated pro rata among the Investors based on the number of Registrable Securities held by each Investor at the time the Registration Statement covering such initial number of Registrable
        Securities or increase or decrease thereof is declared effective by the SEC.  In the event that an Investor sells or otherwise transfers any of such Investor’s Registrable Securities, each transferee shall be allocated a pro rata portion of the
        then remaining number of Registrable Securities included in such Registration Statement for such transferor.  Any shares of Common Stock included in a Registration Statement and which remain allocated to any Person which ceases to hold any
        Registrable Securities covered by such Registration Statement shall be allocated to the remaining Investors, pro rata based on the number of Registrable Securities then held by such Investors which are covered by such Registration Statement.  In no
        event shall the Company include any securities other than Registrable Securities on any Registration Statement without the prior written consent of the Required Holders.

       

      (e)          Legal Counsel.  Subject to Section 5 hereof, the Required Holders shall have the right to select one legal counsel to review and oversee any registration pursuant to this
        Section 2 (“Legal Counsel”), which shall be Schulte Roth & Zabel LLP or such other counsel as thereafter designated by the Required Holders.  The Company and Legal Counsel shall reasonably cooperate with
        each other in performing the Company’s obligations under this Agreement.

       

      (f)          Ineligibility for Form S-3.  In the event that Form S-3 is not available for the registration of the resale of Registrable Securities hereunder, the Company shall (i) register
        the resale of the Registrable Securities on Form S-1 or another appropriate form reasonably acceptable to the Required Holders and (ii) undertake to register the Registrable Securities on Form S-3 as soon as such form is available, provided that
        the Company shall maintain the effectiveness of the Registration Statement then in effect until such time as a Registration Statement on Form S-3 covering the Registrable Securities has been declared effective by the SEC.

       

      
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      (g)          Sufficient Number of Shares Registered.  In the event the number of shares available under a Registration Statement filed pursuant to Section 2(a), Section 2(b) or Section
        2(c) is insufficient to cover the Required Registration Amount of Registrable Securities required to be covered by such Registration Statement or an Investor’s allocated portion of the Registrable Securities pursuant to Section 2(d), the Company
        shall amend the applicable Registration Statement, or file a new Registration Statement (on the short form available therefor, if applicable), or both, so as to cover at least the Required Registration Amount as of the Trading Day immediately
        preceding the date of the filing of such amendment or new Registration Statement, in each case, as soon as practicable, but in any event not later than fifteen (15) days after the necessity therefor arises.  The Company shall use its commercially
        reasonable efforts to cause such amendment and/or new Registration Statement to become effective as soon as practicable following the filing thereof.  For purposes of the foregoing provision, the number of shares available under a Registration
        Statement shall be deemed “insufficient to cover all of the Registrable Securities” if at any time the number of shares of Common Stock available for resale under the Registration Statement is less than the Required Registration Amount as of such
        time.  The calculation set forth in the foregoing sentence shall be made without regard to any limitations on the exercise of the Warrants, and (i) until the Reservation Date, such calculation shall assume that the Series A Warrants and the Series
        B Warrants are then exercisable in full into a number of shares of Common Stock equal to the sum of (x) 135% of the number of Series A Warrant Shares issued and issuable pursuant to the Series A Warrants determined in accordance with Section 2(d)
        of the Series A Warrants assuming a Reset Price (as defined in the Series A Warrants) equal to the Reset Floor Price without giving effect to any limitation on exercise set forth therein and (y) 100% of the number of Series B Warrant Shares issued
        and issuable pursuant to the Series B Warrants assuming that the Maximum Eligibility Number (as defined in the Series B Warrant) is determined based on a Reset Price (as defined in the Series B Warrants) equal to the Reset Floor Price without
        giving effect to any limitation on exercise set forth therein, and (ii) thereafter, the sum of (x) 135% of the maximum number of shares of Common Stock as shall from time to time be necessary to effect the exercise of all of the Series A Warrants
        then outstanding without giving effect to any limitation on exercise set forth therein and (y) 100% of the maximum number of shares of Common Stock as shall from time to time be necessary to effect the exercise of all of the Series B Warrants then
        outstanding without giving effect to any limitation on exercise set forth therein.

       

      
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      (h)          Effect of Failure to File and Obtain and Maintain Effectiveness of Registration Statement.  If (x) a Registration Statement covering all of the Registrable Securities required
        to be covered thereby and required to be filed by the Company pursuant to this Agreement is (A) not filed with the SEC on or before the applicable Filing Deadline (a “Filing Failure”) or (B) not declared
        effective by the SEC on or before the applicable Effectiveness Deadline, (an “Effectiveness Failure”) or (y) on any day after the applicable Effective Date sales of all of the Registrable Securities required
        to be included on such Registration Statement cannot be made (other than during an Allowable Grace Period (as defined in Section 3(r)) pursuant to such Registration Statement or otherwise (including, without limitation, because of the suspension of
        trading or any other limitation imposed by an Eligible Market, a failure to keep such Registration Statement effective, a failure to disclose such information as is necessary for sales to be made pursuant to such Registration Statement, a failure
        to register a sufficient number of shares of Common Stock or a failure to maintain the listing of the Common Stock) (a “Maintenance Failure”), then, as partial relief for the damages to any holder by reason
        of any such delay in or reduction of its ability to sell the Registrable Securities (which remedy shall not be exclusive of any other remedies available at law or in equity, including, without limitation, specific performance or the additional
        obligation of the Company to register any Cutback Shares), the Company shall pay to each holder of Registrable Securities relating to such Registration Statement an amount in cash equal to 1.0% of the aggregate Purchase Price (as such term is
        defined in the Securities Purchase Agreement) of such Investor’s Registrable Securities whether or not included in such Registration Statement on each of the following dates: (i) the day of a Filing Failure; (ii) the day of an Effectiveness
        Failure; (iii) the initial day of a Maintenance Failure; (iv) on the thirtieth day after the date of a Filing Failure and every thirtieth day thereafter (pro rated for periods totaling less than thirty days) until such Filing Failure is cured; (v)
        on the thirtieth day after the date of an Effectiveness Failure and every thirtieth day thereafter (pro rated for periods totaling less than thirty days) until such Effectiveness Failure is cured; and (vi) on the thirtieth day after the initial
        date of a Maintenance Failure and every thirtieth day thereafter (pro rated for periods totaling less than thirty days) until such Maintenance Failure is cured.  The payments to which a holder shall be entitled pursuant to this Section 2(h) are
        referred to herein as “Registration Delay Payments.”  In no event shall the aggregate amount of all Registration Delay Payments payable to an Investor exceed 5.0% of the aggregate Purchase Price of such
        Investor’s Registrable Securities.  Registration Delay Payments shall be paid on the earlier of (I) the dates set forth above and (II) the third Business Day after the event or failure giving rise to the Registration Delay Payments is cured.  In
        the event the Company fails to make Registration Delay Payments in a timely manner, such Registration Delay Payments shall bear interest at the rate of one and one-half percent (1.5%) per month (prorated for partial months) until paid in full. 
        Notwithstanding anything to the contrary set forth herein, the Company shall not be obligated to make any Registration Delay Payments with respect to any Effectiveness Failure resulting from the failure to register any Cutback Shares.

       

       3.           Related Obligations.

       

      At such time as the Company is obligated to file a Registration Statement with the SEC pursuant to Section 2(a), 2(b), 2(c), 2(f) or 2(g), the Company will use its commercially reasonable efforts
        to effect the registration of the Registrable Securities in accordance with the intended method of disposition thereof and, pursuant thereto, the Company shall have the following obligations:

       

      
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      (a)          The Company shall promptly prepare and file with the SEC a Registration Statement with respect to the Registrable Securities and use its commercially reasonable efforts to cause such
        Registration Statement relating to the Registrable Securities to become effective as soon as practicable after such filing (but in no event later than the Effectiveness Deadline).  On and after the applicable Effective Date, the Company shall use
        commercially reasonable efforts to keep each Registration Statement effective pursuant to Rule 415 at all times until the earlier of (i) the date as of which the Investors may sell all of the Registrable Securities covered by such Registration
        Statement without restriction or limitation pursuant to Rule 144 and without the requirement to be in compliance with Rule 144(c)(1) (or any successor thereto) promulgated under the 1933 Act or (ii) the date on which the Investors shall have sold
        all of the Registrable Securities covered by such Registration Statement (the “Registration Period”).  The Company shall ensure that each Registration Statement (including any amendments or supplements
        thereto and prospectuses contained therein) shall not contain any 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 (in the case of prospectuses, in the
        light of the circumstances in which they were made) not misleading.  The term “commercially reasonable efforts” shall mean, among other things, that the Company shall submit to the SEC, within two (2) Business Days after the later of the date that
        (i) the Company learns that no review of a particular Registration Statement will be made by the staff of the SEC or that the staff has no further comments on a particular Registration Statement, as the case may be, and (ii) the approval of Legal
        Counsel pursuant to Section 3(c) (which approval is immediately sought), a request for acceleration of effectiveness of such Registration Statement to a time and date not later than two (2) Business Days after the submission of such request.  The
        Company shall respond in writing to comments made by the SEC in respect of a Registration Statement as soon as practicable, but in no event later than fifteen (15) days after the receipt of comments by or notice from the SEC that an amendment is
        required in order for a Registration Statement to be declared effective.

       

      (b)          The Company shall prepare and file with the SEC such amendments (including post-effective amendments) and supplements to an effective Registration Statement and the prospectus used in
        connection with such Registration Statement, which prospectus is to be filed pursuant to Rule 424 promulgated under the 1933 Act, as may be necessary to keep such Registration Statement effective at all times during the Registration Period, and,
        during such period, comply with the provisions of the 1933 Act with respect to the disposition of all Registrable Securities of the Company covered by such Registration Statement until such time as all of such Registrable Securities shall have been
        disposed of in accordance with the intended methods of disposition by the seller or sellers thereof as set forth in such Registration Statement.  In the case of amendments and supplements to a Registration Statement which are required to be filed
        pursuant to this Agreement (including pursuant to this Section 3(b)) by reason of the Company filing a report on Form 10-K, Form 10-Q or Form 8-K or any analogous report under the Securities Exchange Act of 1934, as amended (the “1934 Act”), the Company shall have incorporated such report by reference into such Registration Statement, if applicable, or shall file such amendments or supplements with the SEC on the same day on which the
        1934 Act report is filed which created the requirement for the Company to amend or supplement such Registration Statement.

       

      (c)          The Company shall (A) permit Legal Counsel to review and comment upon (i) a Registration Statement at least three (3) Business Days prior to its filing with the SEC and (ii) all
        amendments and supplements to all Registration Statements (except for Annual Reports on Form 10-K, Quarterly Reports on Form 10-Q, Current Reports on Form 8-K, and any similar or successor reports) within a reasonable number of days prior to their
        filing with the SEC, and (B) not file any Registration Statement or amendment or supplement thereto in a form to which Legal Counsel reasonably objects.  The Company shall not submit a request for acceleration of the effectiveness of a Registration
        Statement or any amendment or supplement thereto without the prior approval of Legal Counsel, which consent shall not be unreasonably withheld.  The Company shall furnish to Legal Counsel, without charge, (i) copies of any correspondence from the
        SEC or the staff of the SEC to the Company or its representatives relating to any Registration Statement, (ii) unless the following are filed with the SEC through EDGAR and are available to the public through the EDGAR system, promptly after the
        same is prepared and filed with the SEC, one copy of any Registration Statement and any amendment(s) thereto, including financial statements and schedules, all documents incorporated therein by reference, if requested by an Investor, and all
        exhibits and (iii) unless the following are filed with the SEC through EDGAR and are available to the public through the EDGAR system, upon the effectiveness of any Registration Statement, one copy of the prospectus included in such Registration
        Statement and all amendments and supplements thereto.  The Company shall reasonably cooperate with Legal Counsel in performing the Company’s obligations pursuant to this Section 3.

       

      

      
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      (d)        The Company shall furnish to each Investor whose Registrable Securities are included in any Registration Statement, without charge, upon request, (i) promptly after the same is prepared
        and filed with the SEC, at least one copy of such Registration Statement and any amendment(s) thereto, including financial statements and schedules, all documents incorporated therein by reference, if requested by an Investor, all exhibits and each
        preliminary prospectus, (ii) upon the effectiveness of any Registration Statement, ten (10) copies of the prospectus included in such Registration Statement and all amendments and supplements thereto (or such other number of copies as such Investor
        may reasonably request) and (iii) such other documents, including copies of any preliminary or final prospectus, as such Investor may reasonably request from time to time in order to facilitate the disposition of the Registrable Securities owned by
        such Investor.

       

      (e)          The Company shall use its commercially reasonable efforts to (i) register and qualify, unless an exemption from registration and qualification applies, the resale by Investors of the
        Registrable Securities covered by a Registration Statement under such other securities or “blue sky” laws of all applicable jurisdictions in the United States, (ii) following the applicable Effective Date, prepare and file in those jurisdictions
        such amendments (including post-effective amendments) and supplements to such registrations and qualifications as may be necessary to maintain the effectiveness thereof during the Registration Period, (iii) take such other actions as may be
        reasonably necessary to maintain such registrations and qualifications in effect at all times during the Registration Period, and (iv) take all other actions reasonably necessary or advisable to qualify the Registrable Securities for sale in such
        jurisdictions; provided, however, that the Company shall not be required in connection therewith or as a condition thereto to (x) qualify to do business in any jurisdiction where it would not otherwise be required to qualify but for this Section
        3(e), (y) subject itself to general taxation in any such jurisdiction, or (z) file a general consent to service of process in any such jurisdiction.  The Company shall promptly notify Legal Counsel and each Investor who holds Registrable Securities
        of the receipt by the Company of any notification with respect to the suspension of the registration or qualification of any of the Registrable Securities for sale under the securities or “blue sky” laws of any jurisdiction in the United States or
        its receipt of actual notice of the initiation or threatening of any proceeding for such purpose.

       

      (f)         The Company shall notify Legal Counsel and each Investor in writing of the happening of any event, as promptly as practicable after becoming aware of such event but in any event on the
        same Trading Day as such event, as a result of which the prospectus included in a Registration Statement, as then in effect, includes an untrue statement of a material fact or omission to state a material fact required to be stated therein or
        necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading (provided that in no event shall such notice contain any material, nonpublic information), and, subject to Section 3(r), promptly
        prepare a supplement or amendment to such Registration Statement to correct such untrue statement or omission, and, if requested by an Investor, unless filed with the SEC through EDGAR and available to the public through the EDGAR system, deliver
        one copy of such supplement or amendment to Legal Counsel and each Investor (or such other number of copies as Legal Counsel or such Investor may reasonably request).  The Company shall also promptly notify Legal Counsel and each Investor in
        writing (i) when a prospectus or any prospectus supplement or post-effective amendment has been filed, and when a Registration Statement or any post-effective amendment has become effective (notification of such effectiveness shall be delivered to
        Legal Counsel and each Investor by facsimile or email on the same day of such effectiveness and by overnight mail), (ii) of any request by the SEC for amendments or supplements to a Registration Statement or related prospectus or related
        information and (iii) of the Company’s reasonable determination that a post-effective amendment to a Registration Statement would be appropriate.  By 9:30 a.m. New York City time on the Trading Day following the date any post-effective amendment
        has become effective, the Company shall file with the SEC in accordance with Rule 424 under the 1933 Act the final prospectus to be used in connection with sales pursuant to such Registration Statement.

       

      
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      (g)        The Company shall use its commercially reasonable efforts to prevent the issuance of any stop order or other suspension of effectiveness of a Registration Statement, or the suspension
        of the qualification of any of the Registrable Securities for sale in any jurisdiction and, if such an order or suspension is issued, to obtain the withdrawal of such order or suspension at the earliest possible moment and to notify Legal Counsel
        and each Investor who holds Registrable Securities being sold of the issuance of such order and the resolution thereof or its receipt of actual notice of the initiation or threat of any proceeding for such purpose.

       

      (h)          If any Investor is required under applicable securities laws to be described in the Registration Statement as an underwriter or an
        Investor believes that it could reasonably be deemed to be an underwriter of Registrable Securities, at the reasonable request of such Investor, the Company shall furnish to such Investor, on the date of the effectiveness of the Registration
        Statement and thereafter from time to time on such dates as an Investor may reasonably request (i) a letter, dated such date, from the Company’s independent certified public accountants in form and substance as is customarily given by independent
        certified public accountants to underwriters in an underwritten public offering, addressed to the Investors, and (ii) an opinion, dated as of such date, of counsel representing the Company for purposes of such Registration Statement, in form, scope
        and substance as is customarily given in an underwritten public offering, addressed to the Investors.

       

      (i)          If any Investor is required under applicable securities laws to be described in the Registration Statement as an underwriter or an Investor believes that it could reasonably be deemed
        to be an underwriter of Registrable Securities, the Company shall make available for inspection by (i) such Investor, (ii) Legal Counsel and (iii) one firm of accountants or other agents retained by the Investors (collectively, the “Inspectors”), all pertinent financial and other records, and pertinent corporate documents and properties of the Company (collectively, the “Records”), as shall be
        reasonably deemed necessary by each Inspector, and cause the Company’s officers, directors and employees to supply all information which any Inspector may reasonably request; provided, however, that each Inspector shall agree to hold in strict
        confidence and shall not make any disclosure (except to an Investor) or use of any Record or other information which the Company determines in good faith to be confidential, and of which determination the Inspectors are so notified, unless (a) the
        disclosure of such Records is necessary to avoid or correct a misstatement or omission in any Registration Statement or is otherwise required under the 1933 Act, (b) the release of such Records is ordered pursuant to a final, non-appealable
        subpoena or order from a court or government body of competent jurisdiction, or (c) the information in such Records has been made generally available to the public other than by disclosure in violation of this Agreement.  Each Investor agrees that
        it shall, upon learning that disclosure of such Records is sought in or by a court or governmental body of competent jurisdiction or through other means, give prompt notice to the Company and allow the Company, at its expense, to undertake
        appropriate action to prevent disclosure of, or to obtain a protective order for, the Records deemed confidential.  Nothing herein (or in any other confidentiality agreement between the Company and any Investor) shall be deemed to limit the
        Investors’ ability to sell Registrable Securities in a manner which is otherwise consistent with applicable laws and regulations.

       

      
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      (j)         The Company shall hold in confidence and not make any disclosure of information concerning an Investor provided to the Company unless (i) disclosure of such information is necessary to
        comply with federal or state securities laws, (ii) the disclosure of such information is necessary to avoid or correct a misstatement or omission in any Registration Statement, (iii) the release of such information is ordered pursuant to a subpoena
        or other final, non-appealable order from a court or governmental body of competent jurisdiction, or (iv) such information has been made generally available to the public other than by disclosure in violation of this Agreement or any other
        agreement.  The Company agrees that it shall, upon learning that disclosure of such information concerning an Investor is sought in or by a court or governmental body of competent jurisdiction or through other means, give prompt written notice to
        such Investor and allow such Investor, at the Investor’s expense, to undertake appropriate action to prevent disclosure of, or to obtain a protective order for, such information.

       

      (k)        The Company shall use its commercially reasonable efforts either to (i) cause all of the Registrable Securities covered by a Registration Statement to be listed on each securities
        exchange on which securities of the same class or series issued by the Company are then listed, if any, if the listing of such Registrable Securities is then permitted under the rules of such exchange or (ii) secure the inclusion for quotation of
        all of the Registrable Securities on the Principal Market or (iii) if, despite the Company’s commercially reasonable efforts, the Company is unsuccessful in satisfying the preceding clauses (i) and (ii), to secure the inclusion for quotation on an
        Eligible Market for such Registrable Securities and, without limiting the generality of the foregoing, to use its commercially reasonable efforts to arrange for at least two market makers to register with the Financial Industry Regulatory
        Authority, Inc. (“FINRA”) as such with respect to such Registrable Securities.  The Company shall pay all fees and expenses in connection with satisfying its obligation under this Section 3(k).

       

      (l)         The Company shall cooperate with the Investors who hold Registrable Securities being offered and, to the extent applicable, facilitate the timely preparation and delivery of
        certificates (not bearing any restrictive legend) representing the Registrable Securities to be offered pursuant to a Registration Statement and enable such certificates to be in such denominations or amounts, as the case may be, as the Investors
        may reasonably request and registered in such names as the Investors may request.

       

      (m)          If requested by an Investor, the Company shall as soon as practicable (i) incorporate in a prospectus supplement or post-effective amendment such information as an Investor reasonably requests to be
        included therein relating to the sale and distribution of Registrable Securities, including, without limitation, information with respect to the number of Registrable Securities being offered or sold, the purchase price being paid therefor and any
        other terms of the offering of the Registrable Securities to be sold in such offering; (ii) make all required filings of such prospectus supplement or post-effective amendment after being notified of the matters to be incorporated in such
        prospectus supplement or post-effective amendment; and (iii) supplement or make amendments to any Registration Statement if reasonably requested by an Investor holding any Registrable Securities.

       

      

      
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      (n)         The Company shall use its commercially reasonable efforts to cause the Registrable Securities covered by a Registration Statement to be registered with or approved by such other
        governmental agencies or authorities as may be necessary to consummate the disposition of such Registrable Securities.

       

      (o)          The Company shall make generally available to its security holders as soon as practical, but not later than ninety (90) days after the close of the period covered thereby, an earnings
        statement (in form complying with, and in the manner provided by, the provisions of Rule 158 under the 1933 Act) covering a twelve-month period beginning not later than the first day of the Company’s fiscal quarter next following the applicable
        Effective Date of a Registration Statement.

       

      (p)          The Company shall otherwise use its commercially reasonable efforts to comply with all applicable rules and regulations of the SEC in connection with any registration hereunder.

       

      (q)         Within two (2) Business Days after a Registration Statement which covers Registrable Securities is declared effective by the SEC, the Company shall deliver, and shall cause legal
        counsel for the Company to deliver, to the transfer agent for such Registrable Securities (with copies to the Investors whose Registrable Securities are included in such Registration Statement) confirmation that such Registration Statement has been
        declared effective by the SEC in the form attached hereto as Exhibit A.

       

      (r)          Notwithstanding anything to the contrary herein, at any time after the Effective Date, the Company may delay the disclosure of material, non-public information concerning the Company
        the disclosure of which at the time is not, in the good faith opinion of the Board of Directors of the Company and its counsel, in the best interest of the Company and, in the opinion of counsel to the Company, otherwise required (a “Grace Period”); provided, that the Company shall promptly (i) notify the Investors in writing of the existence of material, non-public information giving rise to a Grace Period (provided that in each notice the
        Company will not disclose the content of such material, non-public information to the Investors) and the date on which the Grace Period will begin, and (ii) notify the Investors in writing of the date on which the Grace Period ends; and, provided
        further, that no Grace Period shall exceed five (5) consecutive Trading Days and during any three hundred sixty five (365) day period such Grace Periods shall not exceed an aggregate of forty (40) days and the first day of any Grace Period must be
        at least five (5) Trading Days after the last day of any prior Grace Period (each, an “Allowable Grace Period”).  For purposes of determining the length of a Grace Period above, the Grace Period shall begin
        on and include the date the Investors receive the notice referred to in clause (i) and shall end on and include the later of the date the Investors receive the notice referred to in clause (ii) and the date referred to in such notice.  The
        provisions of Section 3(g) hereof shall not be applicable during the period of any Allowable Grace Period.  Upon expiration of the Grace Period, the Company shall again be bound by the first sentence of Section 3(f) with respect to the information
        giving rise thereto unless such material, non-public information is no longer applicable.  Notwithstanding anything to the contrary, the Company shall cause its transfer agent to deliver unlegended shares of Common Stock to a transferee of an
        Investor in accordance with the terms of the Securities Purchase Agreement in connection with any sale of Registrable Securities with respect to which an Investor has entered into a contract for sale, prior to the Investor’s receipt of the notice
        of a Grace Period and for which the Investor has not yet settled.

       

      
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      (s)          Neither the Company nor any Subsidiary or affiliate thereof shall identify any Investor as an underwriter in any public disclosure or filing with the SEC, the Principal Market or any
        Eligible Market and any Investor being deemed an underwriter by the SEC shall not relieve the Company of any obligations it has under this Agreement or any other Transaction Document (as defined in the Securities Purchase Agreement); provided,
        however, that the foregoing shall not prohibit the Company from including the disclosure found in the “Plan of Distribution” section attached hereto as Exhibit B in the Registration Statement.

       

      (t)          Neither the Company nor any of its Subsidiaries has entered, as of the date hereof, nor shall the Company or any of its Subsidiaries, on or after the date of this Agreement, enter
        into any agreement with respect to its securities, that would have the effect of impairing the rights granted to the Buyers in this Agreement or otherwise conflicts with the provisions hereof.

       

      4.           Obligations of the Investors.

        

      

      (a)          At least five (5) Business Days prior to the first anticipated Filing Date of a Registration Statement, the Company shall notify each Investor in writing of the information the
        Company requires from each such Investor if such Investor elects to have any of such Investor’s Registrable Securities included in such Registration Statement.  It shall be a condition precedent to the obligations of the Company to complete any
        registration pursuant to this Agreement with respect to the Registrable Securities of a particular Investor that such Investor shall furnish 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 to effect and maintain the effectiveness of the registration of such Registrable Securities and shall execute such documents in connection with such
        registration as the Company may reasonably request.

       

      (b)          Each Investor, by such Investor’s 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 any Registration Statement hereunder, unless such Investor has notified the Company in writing of such Investor’s election to exclude all of such Investor’s Registrable Securities from such Registration Statement.

       

      
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      (c)         Each Investor agrees that, upon receipt of any notice from the Company of the happening of any event of the kind described in Section 3(g) or the first sentence of Section 3(f), such
        Investor will immediately discontinue disposition of Registrable Securities pursuant to any Registration Statement(s) covering such Registrable Securities until such Investor’s receipt of copies of the supplemented or amended prospectus as
        contemplated by Section 3(g) or the first sentence of Section 3(f) or receipt of notice that no supplement or amendment is required.  Notwithstanding anything to the contrary, the Company shall cause its transfer agent to deliver unlegended shares
        of Common Stock to a transferee of an Investor in accordance with the terms of the Securities Purchase Agreement in connection with any sale of Registrable Securities with respect to which an Investor has entered into a contract for sale prior to
        the Investor’s receipt of a notice from the Company of the happening of any event of the kind described in Section 3(g) or the first sentence of Section 3(f) and for which the Investor has not yet settled.

       

      (d)          Each Investor covenants and agrees that it will comply with the prospectus delivery requirements of the 1933 Act as applicable to it or an exemption therefrom in connection with sales
        of Registrable Securities pursuant to the Registration Statement.

      

       

      

        5.           Expenses of Registration.

       

      All reasonable expenses, other than underwriting discounts and commissions, incurred in connection with registrations, filings or qualifications pursuant to Sections 2 and 3, including, without
        limitation, all registration, listing and qualifications fees, printers and accounting fees, and fees and disbursements of counsel for the Company shall be paid by the Company.  The Company shall also reimburse the Investors for the fees and
        disbursements of Legal Counsel in connection with the registration, filing or qualification pursuant to Sections 2 and 3 of this Agreement, which amount shall be limited to $10,000 for each such registration, filing or qualification without the
        prior written consent of the Company

       

       6.           Indemnification.

       

       In the event any Registrable Securities are included in a Registration Statement under this Agreement:

       

      (a)           To the fullest extent permitted by law, the Company will, and hereby does, indemnify, hold harmless and defend each Investor, the directors, officers, partners, members, employees,
        agents, representatives of, and each Person, if any, who controls any Investor within the meaning of the 1933 Act or the 1934 Act (each, an “Indemnified Person”), against any losses, claims, damages,
        liabilities, judgments, fines, penalties, charges, costs, reasonable attorneys’ fees, amounts paid in settlement or expenses, joint or several (collectively, “Claims”), incurred in investigating, preparing or
        defending any action, claim, suit, inquiry, proceeding, investigation or appeal taken from the foregoing by or before any court or governmental, administrative or other regulatory agency, body or the SEC, whether pending or threatened, whether or
        not an indemnified party is or may be a party thereto (“Indemnified Damages”), to which any of them may become subject insofar as such Claims (or actions or proceedings, whether commenced or threatened, in
        respect thereof) arise out of or are based upon:  (i) any untrue statement or alleged untrue statement of a material fact in a Registration Statement or any post-effective amendment thereto or in any filing made in connection with the qualification
        of the offering under the securities or other “blue sky” laws of any jurisdiction in which Registrable Securities are offered (“Blue Sky Filing”), or the omission or alleged omission to state a material fact
        required to be stated therein or necessary to make the statements therein not misleading, (ii) any untrue statement or alleged untrue statement of a material fact contained in any preliminary prospectus if used prior to the effective date of such
        Registration Statement, or contained in the final prospectus (as amended or supplemented, if the Company files any amendment thereof or supplement thereto with the SEC) or the omission or alleged omission to state therein any material fact
        necessary to make the statements made therein, in light of the circumstances under which the statements therein were made, not misleading, (iii) any violation or alleged violation by the Company of the 1933 Act, the 1934 Act, any other law,
        including, without limitation, any state securities law, or any rule or regulation thereunder relating to the offer or sale of the Registrable Securities pursuant to a Registration Statement or (iv) any violation of this Agreement (the matters in
        the foregoing clauses (i) through (iv) being, collectively, “Violations”). For the avoidance of doubt, the Violations set forth in this Section 6(a) are intended to apply, and shall apply, to direct claims
        asserted by any Buyer against the Company as well as any third party claims asserted by an Indemnified Person (other than a Buyer) against the Company.  Subject to Section 6(c), the Company shall reimburse the Indemnified Persons, promptly as such
        expenses are incurred and are due and payable, for any legal fees or other reasonable expenses incurred by them in connection with investigating or defending any such Claim.  Notwithstanding anything to the contrary contained herein, the
        indemnification agreement contained in this Section 6(a):  (i) shall not apply to a Claim by an Indemnified Person arising out of or based upon a Violation which occurs in reliance upon and in conformity with information furnished in writing to the
        Company by such Indemnified Person for such Indemnified Person expressly for use in connection with the preparation of the Registration Statement or any such amendment thereof or supplement thereto, if such prospectus was timely made available by
        the Company pursuant to Section 3(d); and (ii) shall not apply to amounts paid in settlement of any Claim if such settlement is effected without the prior written consent of the Company, which consent shall not be unreasonably withheld or delayed. 
        Such indemnity shall remain in full force and effect regardless of any investigation made by or on behalf of the Indemnified Person and shall survive the transfer of the Registrable Securities by the Investors pursuant to Section 9.

       

      

      
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      (b)          In connection with any Registration Statement in which an Investor is participating, each such Investor agrees to severally and not jointly indemnify, hold harmless and defend, to the
        same extent and in the same manner as is set forth in Section 6(a), the Company, each of its directors, each of its officers who signs the Registration Statement and each Person, if any, who controls the Company within the meaning of the 1933 Act
        or the 1934 Act (each, an “Indemnified Party”), against any Claim or Indemnified Damages to which any of them may become subject, under the 1933 Act, the 1934 Act or otherwise, insofar as such Claim or
        Indemnified Damages arise out of or are based upon any Violation, in each case to the extent, and only to the extent, that such Violation occurs in reliance upon and in conformity with written information furnished to the Company by such Investor
        expressly for use in connection with such Registration Statement; and, subject to Section 6(c), such Investor shall reimburse the Indemnified Party for any legal or other expenses reasonably incurred by an Indemnified Party in connection with
        investigating or defending any such Claim; provided, however, that the indemnity agreement contained in this Section 6(b) and the agreement with respect to contribution contained in Section 7 shall not apply to amounts paid in settlement of any
        Claim if such settlement is effected without the prior written consent of such Investor, which consent shall not be unreasonably withheld or delayed; provided, further, however, that the Investor shall be liable under this Section 6(b) for only
        that amount of a Claim or Indemnified Damages as does not exceed the net proceeds to such Investor as a result of the sale of Registrable Securities pursuant to such Registration Statement.  Such indemnity shall remain in full force and effect
        regardless of any investigation made by or on behalf of such Indemnified Party and shall survive the transfer of the Registrable Securities by the Investors pursuant to Section 9.

       

      
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      (c)          Promptly after receipt by an Indemnified Person or Indemnified Party under this Section 6 of notice of the commencement of any action or proceeding (including any governmental action
        or proceeding) involving a Claim, such Indemnified Person or Indemnified Party shall, if a Claim in respect thereof is to be made against any indemnifying party under this Section 6, deliver to the indemnifying party a written notice of the
        commencement thereof, and, the indemnifying party shall have the right to participate in, and, to the extent the indemnifying party so desires, jointly with any other indemnifying party similarly noticed, to assume control of the defense thereof
        with counsel mutually satisfactory to the indemnifying party and the Indemnified Person or the Indemnified Party, as the case may be; provided, however, that an Indemnified Person or Indemnified Party shall have the right to retain its own counsel
        with the fees and expenses of not more than one counsel for all such Indemnified Person or Indemnified Party to be paid by the indemnifying party, if, in the reasonable opinion of counsel retained by the Indemnified Person or Indemnified Party, as
        applicable, the representation by such counsel of the Indemnified Person or Indemnified Party, as the case may be, and the indemnifying party would be inappropriate due to actual or potential differing interests between such Indemnified Person or
        Indemnified Party and any other party represented by such counsel in such proceeding.  In the case of an Indemnified Person, legal counsel referred to in the immediately preceding sentence shall be selected by the Investors holding at least a
        majority in interest of the Registrable Securities included in the Registration Statement to which the Claim relates.  The Indemnified Party or Indemnified Person shall reasonably cooperate with the indemnifying party in connection with any
        negotiation or defense of any such action or Claim by the indemnifying party and shall furnish to the indemnifying party all information reasonably available to the Indemnified Party or Indemnified Person which relates to such action or Claim.  The
        indemnifying party shall keep the Indemnified Party or Indemnified Person fully apprised at all times as to the status of the defense or any settlement negotiations with respect thereto.  No indemnifying party shall be liable for any settlement of
        any action, claim or proceeding effected without its prior written consent, provided, however, that the indemnifying party shall not unreasonably withhold, delay or condition its consent.  No indemnifying party shall, without the prior written
        consent of the Indemnified Party or Indemnified Person, consent to entry of any judgment or enter into any settlement or other compromise which does not include as an unconditional term thereof the giving by the claimant or plaintiff to such
        Indemnified Party or Indemnified Person of a release from all liability in respect to such Claim or litigation and such settlement shall not include any admission as to fault on the part of the Indemnified Party.  Following indemnification as
        provided for hereunder, the indemnifying party shall be subrogated to all rights of the Indemnified Party or Indemnified Person with respect to all third parties, firms or corporations relating to the matter for which indemnification has been
        made.  The failure to deliver written notice to the indemnifying party within a reasonable time of the commencement of any such action shall not relieve such indemnifying party of any liability to the Indemnified Person or Indemnified Party under
        this Section 6, except to the extent that the indemnifying party is prejudiced in its ability to defend such action.  The provisions of this Section 6(c) shall not apply to direct claims between the Company and a Buyer.

       

      
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      (d)          The indemnification required by this Section 6 shall be made by periodic payments of the amount thereof during the course of the investigation or defense, as and when bills are
        received or Indemnified Damages are incurred.

       

      (e)         The indemnity agreements contained herein shall be in addition to (i) any cause of action or similar right of the Indemnified Party or Indemnified Person against the indemnifying party
        or others, and (ii) any liabilities the indemnifying party may be subject to pursuant to the law.

       

       7.           Contribution.

       

      To the extent any indemnification by an indemnifying party is prohibited or limited by law, the indemnifying party agrees to make the maximum contribution with respect to any amounts for which it
        would otherwise be liable under Section 6 to the fullest extent permitted by law; provided, however, that:  (i) no Person involved in the sale of Registrable Securities which Person is guilty of fraudulent misrepresentation (within the meaning of
        Section 11(f) of the 1933 Act) in connection with such sale shall be entitled to contribution from any Person involved in such sale of Registrable Securities who was not guilty of fraudulent misrepresentation; and (ii) contribution by any seller of
        Registrable Securities shall be limited in amount to the amount of net proceeds received by such seller from the sale of such Registrable Securities pursuant to such Registration Statement.

       

       8.           Reports Under the 1934 Act.

       

      With a view to making available to the Investors the benefits of Rule 144 promulgated under the 1933 Act or any other similar rule or regulation of the SEC that may at any time permit the Investors
        to sell securities of the Company to the public without registration (“Rule 144”), the Company agrees to, so long as an Investor owns Registrable Securities:

       

      (a)          make and keep public information available, as those terms are understood and defined in Rule 144;

       

      (b)          file with the SEC in a timely manner all reports and other documents required of the Company under the 1933 Act and the 1934 Act so long as the Company remains subject to such
        requirements and the filing of such reports and other documents is required for the applicable provisions of Rule 144; and

       

      (c)          furnish to each Investor so long as such Investor owns Registrable Securities, promptly upon request, (i) a written statement by the Company, if true, that it has complied with the
        reporting requirements of Rule 144, the 1933 Act and the 1934 Act, (ii) a copy of the most recent annual or quarterly report of the Company and such other reports and documents so filed by the Company (unless such report or document is already
        publicly available), and (iii) such other information as may be reasonably requested to permit the Investors to sell such securities pursuant to Rule 144 without registration.

       

      
        20

        
          


      

       9.           Assignment of Registration Rights.

       

      The rights under this Agreement shall be automatically assignable by the Investors to any transferee of all or any portion of such Investor’s Registrable Securities if:  (i) the Investor agrees in
        writing with the transferee or assignee to assign such rights, and a copy of such agreement is furnished to the Company within a reasonable time after such assignment; (ii) the Company is, within a reasonable time after such transfer or assignment,
        furnished with written notice of (a) the name and address of such transferee or assignee, and (b) the securities with respect to which such registration rights are being transferred or assigned; (iii) immediately following such transfer or
        assignment the further disposition of such securities by the transferee or assignee is restricted under the 1933 Act or applicable state securities laws; (iv) at or before the time the Company receives the written notice contemplated by clause (ii)
        of this sentence the transferee or assignee agrees in writing with the Company to be bound by all of the provisions contained herein; and (v) such transfer shall have been made in accordance with the applicable requirements of the Securities
        Purchase Agreement.

       

      10.         Amendment of Registration Rights.

       

      Provisions of this Agreement may be amended and the observance thereof may be waived (either generally or in a particular instance and either retroactively or prospectively), only with the written
        consent of the Company and the Required Holders.  Any amendment or waiver effected in accordance with this Section 10 shall be binding upon each Investor and the Company.  No such amendment shall be effective to the extent that it applies to less
        than all of the holders of the Registrable Securities.  No consideration shall be offered or paid to any Person to amend or consent to a waiver or modification of any provision of this Agreement unless the same consideration (other than the
        reimbursement of legal fees) also is offered to all of the parties to this Agreement.

       

      11.         Miscellaneous.

       

      (a)          Notwithstanding anything herein to the contrary, this Agreement shall not be effective unless and until the transactions contemplated by the Merger Agreement are consummated. This
        Agreement shall terminate automatically upon termination of the Securities Purchase Agreement if such termination occurs prior to the consummation of the transactions contemplated by the Merger Agreement.

       

      (b)          A Person is deemed to be a holder of Registrable Securities whenever such Person owns or is deemed to own of record such Registrable Securities.  If the Company receives conflicting
        instructions, notices or elections from two or more Persons with respect to the same Registrable Securities, the Company shall act upon the basis of instructions, notice or election received from such record owner of such Registrable Securities.

       

      (c)          Any notices, consents, waivers or other communications required or permitted to be given under the terms of this Agreement must be in writing and will be deemed to have been
        delivered:  (i) upon receipt, when delivered personally; (ii) upon delivery, when sent by facsimile (provided confirmation of transmission is mechanically or electronically generated and kept on file by the sending party), (iii) upon delivery, when
        sent by electronic mail (provided that the sending party does not receive an automated rejection notice); or (iv) one Business Day after deposit with a nationally recognized overnight delivery service, in each case properly addressed to the party
        to receive the same.  The addresses, facsimile numbers and e-mail addresses for such communications shall be:

       

      

      
        21

        
          


      

      
        If to the Company:

         

        Rexahn Pharmaceuticals, Inc.

        15245 Shady Grove Road, Suite 455

        Rockville, MD 20850

        	 	Telephone:	
                (240) 268-5300

              


        	

              	Attention:	
                Douglas J. Swirsky

              


        	

              	E-mail:	
                swirskyd@rexahn.com

              


         

        With a copy (for informational purposes only) to:

         

        Honigman LLP

        650 Trade Centre Way, Suite 200

        Kalamazoo, MI  49002-0402

        	

              	Telephone:	
                (269) 337-7702

              


        	

              	Facsimile:	
                (269) 337-7703

              


        	

              	Attention:	
                Phillip D. Torrence, Esq.

              


        	

              	E-mail:	
                ptorrence@honigman.com

              


        

        

        and, if on or prior to the Closing Date:

        

        

        Hogan Lovells US LLP

        100 International Drive, Suite 2000

        Baltimore, MD 21202

        	

              	Telephone:	
                (410) 659-2700

              


        	

              	Facsimile:	
                (410) 659-2701

              


        	

              	Attention:	
                Asher M. Rubin; William I. Intner

              


        
          	 	
                  E-mail:

                	
                  asher.rubin@hoganlovells.com; 

                


          
            william.intner@hoganlovells.com

          

           

          

        

        If to the Transfer Agent:

         

        Olde Monmouth Stock Transfer Co., Inc.

        200 Memorial Parkway

        Atlantic Highlands, NJ 07716]

        	

              	Telephone:	
                (732) 872-2727, Ext. 101

              


        	

              	Attention:	
                Matthew J. Troster, President

              


        	

              	E-mail:	
                matt@oldemonmouth.com

              


      

       

      

      
        22

        
          


      

      
        If to Legal Counsel:

         

        Schulte Roth & Zabel LLP

        919 Third Avenue

        New York, New York  10022

        	

              	Telephone:	
                (212) 756-2000

              


        	

              	Facsimile:	
                (212) 593-5955

              


        	

              	Attention:	
                Eleazer Klein, Esq.

              


        	

              	Email:	
                eleazer.klein@srz.com

              


      

      

      

      If to a Buyer, to its address, facsimile number or email address set forth on the Schedule of Buyers attached hereto, with copies to such Buyer’s representatives as set forth on the Schedule of Buyers, or to such
        other address, facsimile number and/or email address to the attention of such other Person as the recipient party has specified by written notice given to each other party five (5) days prior to the effectiveness of such change.  Written
        confirmation of receipt (A) given by the recipient of such notice, consent, waiver or other communication, (B) mechanically or electronically generated by the sender’s facsimile machine or e-mail transmission containing the time, date, recipient
        facsimile number or e-mail address and an image of the first page of such transmission or (C) provided by a courier or overnight courier service shall be rebuttable evidence of personal service, receipt by facsimile or receipt from a nationally
        recognized overnight delivery service in accordance with clause (i), (ii) or (iii) above, respectively.

       

      (d)           Failure of any party to exercise any right or remedy under this Agreement or otherwise, or delay by a party in exercising such right or remedy, shall not operate as a waiver thereof.

       

      (e)          All questions concerning the construction, validity, enforcement and interpretation of this Agreement shall be governed by the internal laws of the State of New York, without giving
        effect to any choice of law or conflict of law provision or rule (whether of the State of New York or any other jurisdictions) that would cause the application of the laws of any jurisdictions other than the State of New York.  Each party hereby
        irrevocably submits to the exclusive jurisdiction of the state and federal courts sitting in The City of New York, Borough of Manhattan, for the adjudication of any dispute hereunder or in connection herewith or with any transaction contemplated
        hereby or discussed herein, and hereby irrevocably waives, and agrees not to assert in any suit, action or proceeding, any claim that it is not personally subject to the jurisdiction of any such court, that such suit, action or proceeding is
        brought in an inconvenient forum or that the venue of such suit, action or proceeding is improper.  Each party hereby irrevocably waives personal service of process and consents to process being served in any such suit, action or proceeding by
        mailing a copy thereof to such party at the address for such notices to it under this Agreement and agrees that such service shall constitute good and sufficient service of process and notice thereof.  Nothing contained herein shall be deemed to
        limit in any way any right to serve process in any manner permitted by law.  EACH PARTY HEREBY IRREVOCABLY WAIVES ANY RIGHT IT MAY HAVE, AND AGREES NOT TO REQUEST, A JURY TRIAL FOR THE ADJUDICATION OF ANY DISPUTE
          HEREUNDER OR IN CONNECTION HEREWITH OR ARISING OUT OF THIS AGREEMENT OR ANY TRANSACTION CONTEMPLATED HEREBY.

       

      
        23

        
          


      

      (f)           If any provision of this Agreement is prohibited by law or otherwise determined to be invalid or unenforceable by a court of competent jurisdiction, the provision that would
        otherwise be prohibited, invalid or unenforceable shall be deemed amended to apply to the broadest extent that it would be valid and enforceable, and the invalidity or unenforceability of such provision shall not affect the validity of the
        remaining provisions of this Agreement so long as this Agreement as so modified continues to express, without material change, the original intentions of the parties as to the subject matter hereof and the prohibited nature, invalidity or
        unenforceability of the provision(s) in question does not substantially impair the respective expectations or reciprocal obligations of the parties or the practical realization of the benefits that would otherwise be conferred upon the parties. 
        The parties will endeavor in good faith negotiations to replace the prohibited, invalid or unenforceable provision(s) with a valid provision(s), the effect of which comes as close as possible to that of the prohibited, invalid or unenforceable
        provision(s).

       

      (g)        This Agreement, the other Transaction Documents (as defined in the Securities Purchase Agreement) and the instruments referenced herein and therein constitute the entire agreement among
        the parties hereto with respect to the subject matter hereof and thereof.  There are no restrictions, promises, warranties or undertakings, other than those set forth or referred to herein and therein.  This Agreement, the other Transaction
        Documents and the instruments referenced herein and therein supersede all prior agreements and understandings among the parties hereto with respect to the subject matter hereof and thereof.

       

      (h)           Subject to the requirements of Section 9, this Agreement shall inure to the benefit of and be binding upon the permitted successors and assigns of each of the parties hereto.

       

      (i)           The headings in this Agreement are for convenience of reference only and shall not limit or otherwise affect the meaning hereof.

       

      (j)         This Agreement may be executed in identical counterparts, each of which shall be deemed an original but all of which shall constitute one and the same agreement.  This Agreement, once
        executed by a party, may be delivered to the other party hereto by facsimile transmission or electronic mail of a copy of this Agreement bearing the signature of the party so delivering this Agreement.

       

      (k)          Each party shall do and perform, or cause to be done and performed, all such further acts and things, and shall execute and deliver all such other agreements, certificates,
        instruments and documents, as any other party may reasonably request in order to carry out the intent and accomplish the purposes of this Agreement and the consummation of the transactions contemplated hereby.

       

      (l)          All consents and other determinations required to be made by the Investors pursuant to this Agreement shall be made, unless otherwise specified in this Agreement, by the Required
        Holders, determined as if all of the Warrants held by Investors then outstanding  have been exercised for Registrable Securities without regard to any limitations on exercise of the Warrants.

       

      
        24

        
          


      

      (m)         The language used in this Agreement will be deemed to be the language chosen by the parties to express their mutual intent and no rules of strict construction will be applied against
        any party.

       

      (n)          This Agreement is intended for the benefit of the parties hereto and their respective permitted successors and assigns, and is not for the benefit of, nor may any provision hereof be
        enforced by, any other Person.

       

      (o)          The obligations of each Investor hereunder are several and not joint with the obligations of any other Investor, and no provision of this Agreement is intended to confer any
        obligations on any Investor vis-à-vis any other Investor.  Nothing contained herein, and no action taken by any Investor pursuant hereto, shall be deemed to constitute the Investors as a partnership, an association, a joint venture or any other
        kind of entity, or create a presumption that the Investors are in any way acting in concert or as a group with respect to such obligations or the transactions contemplated herein.

       

      * * * * * *

       

      [Signature Page Follows]

       

      

      
        25

        
          


      

      IN WITNESS WHEREOF, each Buyer and the Company have caused their respective signature page
          to this Registration Rights Agreement to be duly executed as of the date first written above.

       

      	 	
              COMPANY:

            
	 	 
	 	
              REXAHN PHARMACEUTICALS, INC.

            
	 	

            
	 	
              By:

            	
              /s/ Douglas J. Swirsky

            	 
	 	

            	
              Name:

            	
              Douglas J. Swirsky

            	 
	 	 	
              Title:

            	
              President and Chief Executive Officer

            


      

      

      
        
          


      

      
        IN WITNESS WHEREOF, each Buyer and the Company have caused their respective signature page to this Registration Rights Agreement to be duly executed as of
          the date first written above.

         

        	 	
                BUYERS:

              
	 	 	 
	 	
                ALTIUM GROWTH FUND, LP

              
	 	 	 
	 	
                By: Altium Capital Management, LP

              
	 	 	 
	 	
                By:

              	
                /s/ Mark Gottlieb

              	 
	 	 	
                Name: Mark Gottlieb

              
	 	 	
                Title: Chief Operating Officer

              


        

        

        
          
            


        

        IN WITNESS WHEREOF, each Buyer and the Company have caused their respective signature page to this Registration Rights Agreement to be duly executed as of
          the date first written above.

         

        	 	
                OTHER BUYERS:

              
	 	 
	 	
                EMPERY ASSET MASTER, LTD.

              
	 	 
	 	
                By: Empery Asset Master, LP, its authorized agent

              
	 	 
	 	
                By:

              	
                /s/ Brett Director

              	 
	 	 	
                Name: Brett Director

              
	 	 	
                Title: General Counsel

              


         

        

        
          
            


        

        IN WITNESS WHEREOF, each Buyer and the Company have caused their respective signature page to this Registration Rights Agreement to be duly executed as of
          the date first written above.

         

        	 	
                OTHER BUYERS:

              
	 	 	 	 
	 	
                EMPERY TAX EFFICIENT, LP

              
	 	 
	 	
                By: Empery Asset Management, LP, its authorized agent

              
	 	 
	 	
                By:

              	
                /s/ Brett Director

              	 
	 	 	
                Name: Brett Director

              
	 	 	
                Title: General Counsel

              


         

        

        
          
            


        

        IN WITNESS WHEREOF, each Buyer and the Company have caused their respective signature page to this Registration Rights Agreement to be duly executed as of
          the date first written above.

         

        	 	
                OTHER BUYERS:

              
	 	 	 	 
	 	
                EMPERY DEBT OPPORTUNITY FUND, LP

              
	 	 
	 	
                By: Empery Asset Management, LP, its authorized agent

              
	 	 
	 	
                By:

              	
                /s/ Brett Director

              	 
	 	 	
                Name: Brett Director

              
	 	 	
                Title: General Counsel

              


         

        

        
          
            


        

        IN WITNESS WHEREOF, each Buyer and the Company have caused their respective signature page to this Registration Rights Agreement to be duly executed as of
          the date first written above.

        

        

        	 	
                OTHER BUYERS:

              
	 	 	 	 
	 	
                By:

              	
                /s/ Jatinder-Bir S. Sandhu

              	 
	 	 	
                Name: Jatinder-Bir S. Sandhu

              


         

        

        
          
            


        

        IN WITNESS WHEREOF, each Buyer and the Company have caused their respective signature page to this Registration Rights Agreement to be duly executed as of
          the date first written above.

         

        	 	
                OTHER BUYERS:

              
	 	 	 	 
	 	
                By:

              	
                /s/ Devang Shah

              	 
	 	 	
                Name: Devang Shah

              	 


         

        

        
          
            


        

        IN WITNESS WHEREOF, each Buyer and the Company have caused their respective signature page to this Registration Rights Agreement to be duly executed as of
          the date first written above.

         

        	 	
                OTHER BUYERS:

              
	 	 	 	 
	 	
                MICHIGAN ANGEL FUND III, LLC

              
	 	 	 	 
	 	
                By:

              	
                /s/ Joseph Simms

              	 
	 	 	
                Name: Joseph Simms

              
	 	 	
                Title: Managing Member

              


         

        

        
          
            


        

        IN WITNESS WHEREOF, each Buyer and the Company have caused their respective signature page to this Registration Rights Agreement to be duly executed as of
          the date first written above.

         

        	 	
                OTHER BUYERS:

              
	 	 	 	 
	 	
                harry kraemer, jr. and julie m. jansen kraemer

              
	 	 
	 	
                By:

              	
                /s/ Harry M. Kraemer, Jr.

              	 
	 	 	
                Name: Harry M. Kraemer, Jr.

              


         

        

        
          
            


        

        IN WITNESS WHEREOF, each Buyer and the Company have caused their respective signature page to this Registration Rights Agreement to be duly executed as of
          the date first written above.

         

        	 	
                OTHER BUYERS:

              
	 	 	 	 
	 	
                THOMAS TALLERICO TRUST DATED JULY 13, 2018

              
	 	 
	 	
                By:

              	
                /s/ Thomas Tallerico

              	 
	 	 	
                Name: Thomas Tallerico

              
	 	 	
                Title: Trustee

              


         

        

        
          
            


        

        IN WITNESS WHEREOF, each Buyer and the Company have caused their respective signature page to this Registration Rights Agreement to be duly executed as of
          the date first written above.

         

        	 	
                OTHER BUYERS:

              
	 	 	 	 
	 	
                THE BELLE MICHIGAN IMPACT FUND, LP

              
	 	 
	 	
                By:

              	
                /s/ Carolyn Cassin

              	 
	 	 	
                Name: Carolyn Cassin

              
	 	 	
                Title: General Partner

              


         

        

        
          
            


        

        IN WITNESS WHEREOF, each Buyer and the Company have caused their respective signature page to this Registration Rights Agreement to be duly executed as of
          the date first written above.

        

        

        	 	
                OTHER BUYERS:

              
	 	 	 	 
	 	
                BELLE MICHIGAN IMPACT FUND SIDE CAR, LP

              
	 	 
	 	
                By:

              	
                /s/ Carolyn Cassin

              	 
	 	 	
                Name: Carolyn Cassin

              
	 	 	
                Title: General Partner

              


         

        

        
          
            


        

        IN WITNESS WHEREOF, each Buyer and the Company have caused their respective signature page to this Registration Rights Agreement to be duly executed as of
          the date first written above.

         

        	 	
                OTHER BUYERS:

              
	 	 	 	 
	 	
                INVEST DETROIT FOUNDATION d/b/a FIRST CAPITAL FUND

              
	 	 	 	 
	 	
                By:

              	
                /s/ Martin Dober

              	 
	 	 	
                Name: Martin Dober

              
	 	 	
                Title: SVP and Managing Director

              


         

        

        
          
            


        

        IN WITNESS WHEREOF, each Buyer and the Company have caused their respective signature page to this Registration Rights Agreement to be duly executed as of
          the date first written above.

         

        	 	
                OTHER BUYERS:

              
	 	 	 	 
	 	
                By:

              	
                /s/ Mina Sooch

              	 
	 	 	
                Name: Mina Sooch

              


         

        

        
          
            


        

        IN WITNESS WHEREOF, each Buyer and the Company have caused their respective signature page to this Registration Rights Agreement to be duly executed as of
          the date first written above.

         

        	 	
                OTHER BUYERS:

              
	 	 	 	 
	 	
                By:

              	
                /s/ Richard J. Rodgers

              	 
	 	 	
                Name: Richard J. Rodgers

              	 


         

        

        
          
            


        

        IN WITNESS WHEREOF, each Buyer and the Company have caused their respective signature page to this Registration Rights Agreement to be duly executed as of
          the date first written above.

         

        	 	
                OTHER BUYERS:

              
	 	 	 	 
	 	
                By:

              	
                /s/ Alan R. Meyer

              	 
	 	 	
                Name: Alan R. Meyer

              


         

        

        
          
            


        

        IN WITNESS WHEREOF, each Buyer and the Company have caused their respective signature page to this Registration Rights Agreement to be duly executed as of
          the date first written above.

         

        	 	
                OTHER BUYERS:

              
	 	 	 	 
	 	
                By:

              	
                /s/ James S. Manuso

              	 
	 	 	
                Name: James S. Manuso

              


         

        

        
          
            


        

        IN WITNESS WHEREOF, each Buyer and the Company have caused their respective signature page to this Registration Rights Agreement to be duly executed as of
          the date first written above.

         

        	 	
                OTHER BUYERS:

              
	 	 	 	 
	 	
                By:

              	
                /s/ Cam Gallagher

              	 
	 	 	
                Name: Cam Gallagher

              


         

        

        
          
            


        

        IN WITNESS WHEREOF, each Buyer and the Company have caused their respective signature page to this Registration Rights Agreement to be duly executed as of
          the date first written above.

         

        	 	
                OTHER BUYERS:

              
	 	 	 	 
	 	
                By:

              	
                /s/ Sean Ainsworth

              	 
	 	 	
                Name: Sean Ainsworth

              


        

        

      

      
        
          


      

      SCHEDULE OF BUYERS

      

      

      	
              
                Buyer

              

            	

            	
              
                Address, Facsimile Number

                and E-mail

              

            


      

      

      
        
          


      

      
      EXHIBIT A

       

      FORM OF NOTICE OF EFFECTIVENESS

      OF REGISTRATION STATEMENT

       

      	
              Olde Monmouth Stock Transfer Co., Inc.

            
	
              200 Memorial Parkway

            
	
              Atlantic Highlands, NJ 07716]

            
	
              Telephone:

            	
              (732) 872-2727, Ext. 101

            
	
              Attention:

            	
              Matthew J. Troster, President

            
	
              E-mail:

            	
              matt@oldemonmouth.com

            


       

      	

            	Re:	
              Rexahn Pharmaceuticals, Inc.

            


       

      Ladies and Gentlemen:

       

      [We are][I am] counsel to Rexahn Pharmaceuticals, Inc., a Delaware corporation to be renamed “Ocuphire Pharma, Inc.” (the “Company”) pursuant to that certain
        Agreement and Plan of Merger and Reorganization among the Company, Razor Merger Sub, Inc., a Delaware corporation and wholly owned subsidiary of the Company and Ocuphire Pharma, Inc., a Delaware corporation (“Ocuphire



          Private Company”), dated as of June [•], 2020, and have represented the Company in connection with that certain Securities Purchase Agreement, dated as of [●], 2020 (the “Securities Purchase Agreement”), entered into by and among the Company, Ocuphire Private Company, and the buyers named therein (collectively, the “Holders”) pursuant to which Ocuphire
        Private Company issued to the Holders shares of common stock, [•] par value per share, of Ocuphire Private Company, and the Company issued to the Holders two series of warrants (the “Warrants”) exercisable
        for shares of the Company’s common stock, par value $0.0001 per share (the “Common Stock”).  Pursuant to the Securities Purchase Agreement, the Company also has entered into a Registration Rights Agreement
        with the Holders (the “Registration Rights Agreement”) pursuant to which the Company agreed, among other things, to register the resale of the Registrable Securities (as defined in the Registration Rights
        Agreement), including the shares of Common Stock issuable upon exercise of the Warrants under the Securities Act of 1933, as amended (the “1933 Act”).  In connection with the Company’s obligations under the
        Registration Rights Agreement, on ____________ ___, 20__, the Company filed a Registration Statement on Form S-3 (File No. 333-_____________) (the “Registration Statement”) with the Securities and Exchange
        Commission (the “SEC”) relating to the Registrable Securities which names each of the Holders as a selling stockholder thereunder.

       

      In connection with the foregoing, [we][I] advise you that a member of the SEC’s staff has advised [us][me] by telephone that the SEC has entered an order declaring the Registration Statement
        effective under the 1933 Act at [ENTER TIME OF EFFECTIVENESS] on [ENTER DATE OF EFFECTIVENESS]
        and [we][I] have no knowledge, after telephonic inquiry of a member of the SEC’s staff, that any stop order suspending its effectiveness has been issued or that any proceedings for that purpose are pending before, or threatened by, the SEC and the
        Registrable Securities are available for resale under the 1933 Act pursuant to the Registration Statement.

       

      

      
        A-1

        
          


      

      This letter shall serve as our standing instruction to you that the shares of Common Stock are freely transferable by the Holders pursuant to the Registration Statement.  You need not require
        further letters from us to effect any future legend-free issuance or reissuance of shares of Common Stock to the Holders as contemplated by the Company’s Irrevocable Transfer Agent Instructions dated [●].

       

      	 	
              Very truly yours,

            
	 	 
	 	
              [ISSUER’S COUNSEL]

            
	 	 
	 	
              By:

            	 	 
	
              CC: [LIST NAMES OF HOLDERS]

            	 	 	 


       

      

      
        A-2

        
          


      

      
      EXHIBIT B

      SELLING STOCKHOLDERS

       

      The shares of common stock being offered by the selling stockholders are those issuable to the selling stockholders, upon exercise of the warrants.  For additional information regarding the
        issuances of those shares of common stock and the warrants, see “Private Placement of Common Shares and Warrants” above.  We are registering the Common Stock in order to permit the selling stockholders to offer the shares for resale from time to
        time.  Except for the ownership of the shares of common stock and the warrants, the selling stockholders have not had any material relationship with us within the past three years.

       

      The table below lists the selling stockholders and other information regarding the beneficial ownership of the shares of common stock by each of the selling stockholders.  The second column lists
        the number of shares of common stock beneficially owned by each selling stockholder, based on its ownership of the shares of common stock and the warrants, as of ________, 20__, assuming exercise of the warrants held by the selling stockholders on
        that date, without regard to any limitations on exercises.

       

      The third column lists the shares of common stock being offered by this prospectus by the selling stockholders.

       

      In accordance with the terms of a registration rights agreement with the selling stockholders, this prospectus generally covers the resale of the maximum number of shares of common stock issuable
        upon exercise of the related warrants, determined as if the outstanding warrants were exercised in full as of the trading day immediately preceding the date this registration statement was initially filed with the SEC, each as of the trading day
        immediately preceding the applicable date of determination and all subject to adjustment as provided in the registration rights agreement, without regard to any limitations on the exercise of the Series A Warrants and the Series B Warrants and this
        registration statement registers (A) until the Reservation Date, a number of shares of common stock issued and issuable pursuant to the Series A Warrants and Series B Warrants equal to the sum of (x) 135% of the number of Series A Warrant Shares
        issued and issuable pursuant to the Series A Warrants determined in accordance with Section 2(d) of the Series A Warrants assuming a Reset Price (as defined in the Series A Warrants) equal to the Reset Floor Price (as defined in the warrants)
        without giving effect to any limitation on exercise set forth therein and (y) 100% of the number of Series B Warrant Shares issued and issuable pursuant to the Series B Warrants assuming that the Maximum Eligibility Number (as defined in the Series
        B Warrant) is determined based on a Reset Price (as defined in the Series B Warrants) equal to the Reset Floor Price without giving effect to any limitation on exercise set forth therein and (B) from and after the Reservation date, the sum of (x)
        135% of the maximum number of shares of Common Stock issuable upon exercise of the Series A Warrants as shall from time to time be necessary to effect the exercise of all of the Series A Warrants then outstanding without giving effect to any
        limitation on exercise set forth in the Series A Warrants and (y) 100% of the maximum number of shares of Common Stock issuable upon exercise of the Series B Warrants as shall from time to time be necessary to effect the exercise of all of the
        Series B Warrants then outstanding without giving effect to any limitation on exercise set forth in the Series B Warrants.  The fourth column assumes the sale of all of the shares offered by the selling stockholders pursuant to this prospectus.

       

      
        Annex I-1

        
          


      

      
      Under the terms of the Series A Warrants and the Series B Warrants, a selling stockholder may not exercise the Series A Warrants or the Series B Warrants to the extent such exercise would cause
        such selling stockholder, together with its affiliates, to beneficially own a number of shares of common stock which would exceed 4.99% or 9.99%, as applicable, of our then outstanding common stock following such exercise, excluding for purposes of
        such determination common stock issuable upon exercise of the warrants which have not been exercised.  The number of shares in the second column does not reflect this limitation.  The selling stockholders may sell all, some or none of their shares
        in this offering.  See “Plan of Distribution.”

       

      	
               

              Name of Selling Stockholder

            	
              Number of Shares

               of Common Stock

               Owned Prior to

               Offering

            	
              Maximum Number of 

              Shares of Common

               Stock to be Sold 

              Pursuant to this 

              Prospectus

            	
              Number of Shares of 

              Common Stock 

              Owned After 

              Offering

            	
              Percentage of 

              Shares of

               Common Stock

               Owned After 

              Offering if

               Greater than 1%

            


      

      

      
        Annex I-2

        
          


      

      PLAN OF DISTRIBUTION

       

      We are registering the shares of common stock issued and issuable upon exercise of the warrants to permit the resale of these shares of common stock by the holders of the common stock warrants from
        time to time after the date of this prospectus.  We will not receive any of the proceeds from the sale by the selling stockholders of the shares of common stock.  We will bear all fees and expenses incident to our obligation to register the shares
        of common stock.

       

      The selling stockholders may sell all or a portion of the shares of common stock beneficially owned by them and offered hereby from time to time directly or through one or more underwriters,
        broker-dealers or agents.  If the shares of common stock are sold through underwriters or broker-dealers, the selling stockholders will be responsible for underwriting discounts or commissions or agent’s commissions.  The shares of common stock may
        be sold in one or more transactions at fixed prices, at prevailing market prices at the time of the sale, at varying prices determined at the time of sale, or at negotiated prices.  These sales may be effected in transactions, which may involve
        crosses or block transactions,

       

      	

            	•	
              on any national securities exchange or quotation service on which the securities may be listed or quoted at the time of sale;

            


       

      	

            	•	
              in the over-the-counter market;

            


       

      	

            	•	
              in transactions otherwise than on these exchanges or systems or in the over-the-counter market;

            


       

      	

            	•	
              through the writing of options, whether such options are listed on an options exchange or otherwise;

            


       

      	

            	•	
              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;

            


       

      	

            	•	
              sales pursuant to Rule 144;

            


       

      	

            	•	
              broker-dealers may agree with the selling securityholders 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 pursuant to applicable law.

            


       

      
        Annex I-3

        
          


      

      If the selling stockholders effect such transactions by selling shares of common stock to or through underwriters, broker-dealers or agents, such underwriters, broker-dealers or agents may receive
        commissions in the form of discounts, concessions or commissions from the selling stockholders or commissions from purchasers of the shares of common stock for whom they may act as agent or to whom they may sell as principal (which discounts,
        concessions or commissions as to particular underwriters, broker-dealers or agents may be in excess of those customary in the types of transactions involved).  In connection with sales of the shares of common stock or otherwise, the selling
        stockholders may enter into hedging transactions with broker-dealers, which may in turn engage in short sales of the shares of common stock in the course of hedging in positions they assume.  The selling stockholders may also sell shares of common
        stock short and deliver shares of common stock covered by this prospectus to close out short positions and to return borrowed shares in connection with such short sales.  The selling stockholders may also loan or pledge shares of common stock to
        broker-dealers that in turn may sell such shares.

       

      The selling stockholders may pledge or grant a security interest in some or all of the warrants or 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 pursuant to this prospectus or any amendment to this prospectus under Rule 424(b)(3) or other applicable provision of the Securities Act of
        1933, as amended, amending, if necessary, 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 and donate the
        shares of common stock in other circumstances in which case the transferees, donees, pledgees or other successors in interest will be the selling beneficial owners for purposes of this prospectus.

       

      The selling stockholders and any broker-dealer participating in the distribution of the shares of common stock may be deemed to be “underwriters” within the meaning of the Securities Act, and any
        commission paid, or any discounts or concessions allowed to, any such broker-dealer may be deemed to be underwriting commissions or discounts under the Securities Act.  At the time a particular offering of the shares of common stock is made, a
        prospectus supplement, if required, will be distributed which will set forth the aggregate amount of shares of common stock being offered and the terms of the offering, including the name or names of any broker-dealers or agents, any discounts,
        commissions and other terms constituting compensation from the selling stockholders and any discounts, commissions or concessions allowed or reallowed or paid to broker-dealers.

       

      Under the securities laws of some states, the shares of common stock may be sold in such states only through registered or licensed brokers or dealers.  In addition, in some states the shares of
        common stock may not be sold unless such shares have been registered or qualified for sale in such state or an exemption from registration or qualification is available and is complied with.

       

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

       

      
        Annex I-4

        
          


      

      The selling stockholders and any other person participating in such distribution will be subject to applicable provisions of the Securities Exchange Act of 1934, as amended, and the rules and
        regulations thereunder, including, without limitation, Regulation M of the Exchange Act, which may limit the timing of purchases and sales of any of the shares of common stock by the selling stockholders and any other participating person. 
        Regulation M may also restrict the ability of any person engaged in the distribution of the shares of common stock to engage in market-making activities with respect to the shares of common stock.  All of the foregoing may affect the marketability
        of the shares of common stock and the ability of any person or entity to engage in market-making activities with respect to the shares of common stock.

       

      We will pay all 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; provided, however, that a selling stockholder will pay all underwriting discounts and selling commissions, if any.  We will
        indemnify the selling stockholders against liabilities, including some liabilities under the Securities Act, in accordance with the registration rights agreements, or the selling stockholders will be entitled to contribution.  We may be indemnified
        by the selling stockholders against civil liabilities, including liabilities under the Securities Act, that may arise from any written information furnished to us by the selling stockholder specifically for use in this prospectus, in accordance
        with the related registration rights agreement, or we may be entitled to contribution.

       

      Once sold under the registration statement, of which this prospectus forms a part, the shares of common stock will be freely tradable in the hands of persons other than our affiliates.

       

       

      

      Annex I-5