• Live Feeds
    • Press Releases
    • Insider Trading
    • FDA Approvals
    • Analyst Ratings
    • Insider Trading
    • SEC filings
    • Market insights
  • Analyst Ratings
  • Alerts
  • Subscriptions
  • Settings
  • RSS Feeds
Quantisnow Logo
  • Live Feeds
    • Press Releases
    • Insider Trading
    • FDA Approvals
    • Analyst Ratings
    • Insider Trading
    • SEC filings
    • Market insights
  • Analyst Ratings
  • Alerts
  • Subscriptions
  • Settings
  • RSS Feeds
PublishGo to App
    Quantisnow Logo

    © 2026 quantisnow.com
    Democratizing insights since 2022

    Services
    Live news feedsRSS FeedsAlertsPublish with Us
    Company
    AboutQuantisnow PlusContactJobsAI superconnector for talent & startupsNEWLLM Arena
    Legal
    Terms of usePrivacy policyCookie policy

    SEC Form SC 13G filed by Mersana Therapeutics Inc.

    8/7/23 4:15:35 PM ET
    $MRSN
    Biotechnology: Pharmaceutical Preparations
    Health Care
    Get the next $MRSN alert in real time by email
    SC 13G 1 tm2322987d1_sc13g.htm SC 13G

     

     

    UNITED STATES

    SECURITIES AND EXCHANGE COMMISSION

    Washington, D.C. 20549

     

    SCHEDULE 13G

     

    Under the Securities Exchange Act of 1934

    (Amendment No. )*

     

    Mersana Therapeutics, Inc.

    (Name of Issuer)

     

    Common Stock, $0.0001 par value per share

    (Title of Class of Securities)

     

    59045L106

    (CUSIP Number)

     

    July 28, 2023

    (Date of Event Which Requires Filing of this Statement)

     

    Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

     

     ¨Rule 13d-1(b)
     xRule 13d-1(c)
     ¨Rule 13d-1(d)

     

    *The remainder of this cover page shall be filled out for a reporting person's initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page.

     

    The information required in the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

     

     

     

     

     

    CUSIP No. 59045L106Page 2 of 17

     

    1.

    Names of Reporting Persons

     

    Venrock Healthcare Capital Partners III, L.P.

    2.

    Check the Appropriate Box if a Member of a Group (See Instructions)

     

    (a) x (1)  (b) ¨

    3.

    SEC Use Only

     

    4.

    Citizenship or Place of Organization

     

    Delaware

    Number of

    Shares

    Beneficially

    Owned by

    Each

    Reporting

    Person With

    5.

    Sole Voting Power

     

    0

    6.

    Shared Voting Power

     

    9,678,000 (2)

    7.

    Sole Dispositive Power

     

    0

    8.

    Shared Dispositive Power

     

    9,678,000 (2)

    9.

    Aggregate Amount Beneficially Owned by Each Reporting Person

     

    9,678,000 (2)

    10.

    Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions)    ¨

     

    11.

    Percent of Class Represented by Amount in Row (9)

     

    8.5% (3)

    12.

    Type of Reporting Person (See Instructions)

     

    PN

           

    (1)Venrock Healthcare Capital Partners III, L.P., VHCP Co-Investment Holdings III, LLC, Venrock Healthcare Capital Partners EG, L.P., VHCP Management III, LLC, VHCP Management EG, LLC, Nimish Shah and Bong Koh are members of a group for the purposes of this Schedule 13G.

     

    (2)Consists of (i) 2,544,347 shares held by Venrock Healthcare Capital Partners III, L.P.; (ii) 254,531 shares held by VHCP Co-Investment Holdings III, LLC; and (iii) 6,879,122 shares held by Venrock Healthcare Capital Partners EG, L.P.

     

    (3)This percentage is calculated based upon 114,385,810 shares of Common Stock outstanding as of May 5, 2023, as reported in the Issuer’s Quarterly Report on Form 10-Q for the quarterly period ended March 31, 2023 filed with the Securities and Exchange Commission on May 9, 2023.

     

     

     

     

    CUSIP No. 59045L106Page 3 of 17

     

    1.

    Names of Reporting Persons

     

    VHCP Co-Investment Holdings III, LLC

    2.

    Check the Appropriate Box if a Member of a Group (See Instructions)

     

    (a) x (1)  (b) ¨

    3.

    SEC Use Only

     

    4.

    Citizenship or Place of Organization

     

    Delaware

    Number of

    Shares

    Beneficially

    Owned by

    Each

    Reporting

    Person With

    5.

    Sole Voting Power

     

    0

    6.

    Shared Voting Power

     

    9,678,000 (2)

    7.

    Sole Dispositive Power

     

    0

    8.

    Shared Dispositive Power

     

    9,678,000 (2)

    9.

    Aggregate Amount Beneficially Owned by Each Reporting Person

     

    9,678,000 (2)

    10.

    Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions)    ¨

     

    11.

    Percent of Class Represented by Amount in Row (9)

     

    8.5% (3)

    12.

    Type of Reporting Person (See Instructions)

     

    OO

           

    (1)Venrock Healthcare Capital Partners III, L.P., VHCP Co-Investment Holdings III, LLC, Venrock Healthcare Capital Partners EG, L.P., VHCP Management III, LLC, VHCP Management EG, LLC, Nimish Shah and Bong Koh are members of a group for the purposes of this Schedule 13G.

     

    (2)Consists of (i) 2,544,347 shares held by Venrock Healthcare Capital Partners III, L.P.; (ii) 254,531 shares held by VHCP Co-Investment Holdings III, LLC; and (iii) 6,879,122 shares held by Venrock Healthcare Capital Partners EG, L.P.

     

    (3)This percentage is calculated based upon 114,385,810 shares of Common Stock outstanding as of May 5, 2023, as reported in the Issuer’s Quarterly Report on Form 10-Q for the quarterly period ended March 31, 2023 filed with the Securities and Exchange Commission on May 9, 2023.

     

     

     

     

    CUSIP No. 59045L106Page 4 of 17

     

    1.

    Names of Reporting Persons

     

    Venrock Healthcare Capital Partners EG, L.P.

    2.

    Check the Appropriate Box if a Member of a Group (See Instructions)

     

    (a) x (1)  (b) ¨

    3.

    SEC Use Only

     

    4.

    Citizenship or Place of Organization

     

    Delaware

    Number of

    Shares

    Beneficially

    Owned by

    Each

    Reporting

    Person With

    5.

    Sole Voting Power

     

    0

    6.

    Shared Voting Power

     

    9,678,000 (2)

    7.

    Sole Dispositive Power

     

    0

    8.

    Shared Dispositive Power

     

    9,678,000 (2)

    9.

    Aggregate Amount Beneficially Owned by Each Reporting Person

     

    9,678,000 (2)

    10.

    Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions)    ¨

     

    11.

    Percent of Class Represented by Amount in Row (9)

     

    8.5% (3)

    12.

    Type of Reporting Person (See Instructions)

     

    PN

           

     

    (1)Venrock Healthcare Capital Partners III, L.P., VHCP Co-Investment Holdings III, LLC, Venrock Healthcare Capital Partners EG, L.P., VHCP Management III, LLC, VHCP Management EG, LLC, Nimish Shah and Bong Koh are members of a group for the purposes of this Schedule 13G.

     

    (2)Consists of (i) 2,544,347 shares held by Venrock Healthcare Capital Partners III, L.P.; (ii) 254,531 shares held by VHCP Co-Investment Holdings III, LLC; and (iii) 6,879,122 shares held by Venrock Healthcare Capital Partners EG, L.P.

     

    (3)This percentage is calculated based upon 114,385,810 shares of Common Stock outstanding as of May 5, 2023, as reported in the Issuer’s Quarterly Report on Form 10-Q for the quarterly period ended March 31, 2023 filed with the Securities and Exchange Commission on May 9, 2023.

     

     

     

     

    CUSIP No. 59045L106Page 5 of 17

     

    1.

    Names of Reporting Persons

     

    VHCP Management III, LLC

    2.

    Check the Appropriate Box if a Member of a Group (See Instructions)

     

    (a) x (1)  (b) ¨

    3.

    SEC Use Only

     

    4.

    Citizenship or Place of Organization

     

    Delaware

    Number of

    Shares

    Beneficially

    Owned by

    Each

    Reporting

    Person With

    5.

    Sole Voting Power

     

    0

    6.

    Shared Voting Power

     

    9,678,000 (2)

    7.

    Sole Dispositive Power

     

    0

    8.

    Shared Dispositive Power

     

    9,678,000 (2)

    9.

    Aggregate Amount Beneficially Owned by Each Reporting Person

     

    9,678,000 (2)

    10.

    Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions)    ¨

     

    11.

    Percent of Class Represented by Amount in Row (9)

     

    8.5% (3)

    12.

    Type of Reporting Person (See Instructions)

     

    OO

           

    (1)Venrock Healthcare Capital Partners III, L.P., VHCP Co-Investment Holdings III, LLC, Venrock Healthcare Capital Partners EG, L.P., VHCP Management III, LLC, VHCP Management EG, LLC, Nimish Shah and Bong Koh are members of a group for the purposes of this Schedule 13G.

     

    (2)Consists of (i) 2,544,347 shares held by Venrock Healthcare Capital Partners III, L.P.; (ii) 254,531 shares held by VHCP Co-Investment Holdings III, LLC; and (iii) 6,879,122 shares held by Venrock Healthcare Capital Partners EG, L.P.

     

    (3)This percentage is calculated based upon 114,385,810 shares of Common Stock outstanding as of May 5, 2023, as reported in the Issuer’s Quarterly Report on Form 10-Q for the quarterly period ended March 31, 2023 filed with the Securities and Exchange Commission on May 9, 2023.

     

     

     

     

    CUSIP No. 59045L106Page 6 of 17

     

    1.

    Names of Reporting Persons

     

    VHCP Management EG, LLC

    2.

    Check the Appropriate Box if a Member of a Group (See Instructions)

     

    (a) x (1)  (b) ¨

    3.

    SEC Use Only

     

    4.

    Citizenship or Place of Organization

     

    Delaware

    Number of

    Shares

    Beneficially

    Owned by

    Each

    Reporting

    Person With

    5.

    Sole Voting Power

     

    0

    6.

    Shared Voting Power

     

    9,678,000 (2)

    7.

    Sole Dispositive Power

     

    0

    8.

    Shared Dispositive Power

     

    9,678,000 (2)

    9.

    Aggregate Amount Beneficially Owned by Each Reporting Person

     

    9,678,000 (2)

    10.

    Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions)    ¨

     

    11.

    Percent of Class Represented by Amount in Row (9)

     

    8.5% (3)

    12.

    Type of Reporting Person (See Instructions)

     

    OO

           

    (1)Venrock Healthcare Capital Partners III, L.P., VHCP Co-Investment Holdings III, LLC, Venrock Healthcare Capital Partners EG, L.P., VHCP Management III, LLC, VHCP Management EG, LLC, Nimish Shah and Bong Koh are members of a group for the purposes of this Schedule 13G.

     

    (2)Consists of (i) 2,544,347 shares held by Venrock Healthcare Capital Partners III, L.P.; (ii) 254,531 shares held by VHCP Co-Investment Holdings III, LLC; and (iii) 6,879,122 shares held by Venrock Healthcare Capital Partners EG, L.P.

     

    (3)This percentage is calculated based upon 114,385,810 shares of Common Stock outstanding as of May 5, 2023, as reported in the Issuer’s Quarterly Report on Form 10-Q for the quarterly period ended March 31, 2023 filed with the Securities and Exchange Commission on May 9, 2023.

     

     

     

     

    CUSIP No. 59045L106Page 7 of 17

     

    1.

    Names of Reporting Persons

     

    Shah, Nimish

    2.

    Check the Appropriate Box if a Member of a Group (See Instructions)

     

    (a) x (1)  (b) ¨

    3.

    SEC Use Only

     

    4.

    Citizenship or Place of Organization

     

    United States 

    Number of

    Shares

    Beneficially

    Owned by

    Each

    Reporting

    Person With

    5.

    Sole Voting Power

     

    0

    6.

    Shared Voting Power

     

    9,678,000 (2)

    7.

    Sole Dispositive Power

     

    0

    8.

    Shared Dispositive Power

     

    9,678,000 (2)

    9.

    Aggregate Amount Beneficially Owned by Each Reporting Person

     

    9,678,000 (2)

    10.

    Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions)    ¨

     

    11.

    Percent of Class Represented by Amount in Row (9)

     

    8.5% (3)

    12.

    Type of Reporting Person (See Instructions)

     

    IN

           

    (1)Venrock Healthcare Capital Partners III, L.P., VHCP Co-Investment Holdings III, LLC, Venrock Healthcare Capital Partners EG, L.P., VHCP Management III, LLC, VHCP Management EG, LLC, Nimish Shah and Bong Koh are members of a group for the purposes of this Schedule 13G.

     

    (2)Consists of (i) 2,544,347 shares held by Venrock Healthcare Capital Partners III, L.P.; (ii) 254,531 shares held by VHCP Co-Investment Holdings III, LLC; and (iii) 6,879,122 shares held by Venrock Healthcare Capital Partners EG, L.P.

     

    (3)This percentage is calculated based upon 114,385,810 shares of Common Stock outstanding as of May 5, 2023, as reported in the Issuer’s Quarterly Report on Form 10-Q for the quarterly period ended March 31, 2023 filed with the Securities and Exchange Commission on May 9, 2023.

     

     

     

     

    CUSIP No. 59045L106Page 8 of 17

     

    1.

    Names of Reporting Persons

     

    Koh, Bong

    2.

    Check the Appropriate Box if a Member of a Group (See Instructions)

     

    (a) x (1)  (b) ¨

    3.

    SEC Use Only

     

    4.

    Citizenship or Place of Organization

     

    United States

    Number of

    Shares

    Beneficially

    Owned by

    Each

    Reporting

    Person With

    5.

    Sole Voting Power

     

    0

    6.

    Shared Voting Power

     

    9,678,000 (2)

    7.

    Sole Dispositive Power

     

    0

    8.

    Shared Dispositive Power

     

    9,678,000 (2)

    9.

    Aggregate Amount Beneficially Owned by Each Reporting Person

     

    9,678,000 (2)

    10.

    Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions)    ¨

     

    11.

    Percent of Class Represented by Amount in Row (9)

     

    8.5% (3)

    12.

    Type of Reporting Person (See Instructions)

     

    IN

           

    (1)Venrock Healthcare Capital Partners III, L.P., VHCP Co-Investment Holdings III, LLC, Venrock Healthcare Capital Partners EG, L.P., VHCP Management III, LLC, VHCP Management EG, LLC, Nimish Shah and Bong Koh are members of a group for the purposes of this Schedule 13G.

     

    (2)Consists of (i) 2,544,347 shares held by Venrock Healthcare Capital Partners III, L.P.; (ii) 254,531 shares held by VHCP Co-Investment Holdings III, LLC; and (iii) 6,879,122 shares held by Venrock Healthcare Capital Partners EG, L.P.

     

    (3)This percentage is calculated based upon 114,385,810 shares of Common Stock outstanding as of May 5, 2023, as reported in the Issuer’s Quarterly Report on Form 10-Q for the quarterly period ended March 31, 2023 filed with the Securities and Exchange Commission on May 9, 2023.

     

     

     

     

    CUSIP No. 59045L106Page 9 of 17

     

    Item 1.
      (a)

    Name of Issuer

     

    Mersana Therapeutics, Inc.

     
      (b)

    Address of Issuer’s Principal Executive Offices

     

    840 Memorial Drive

    Cambridge, MA 02139

     
    Item 2.
      (a)

    Name of Person Filing

     

    Venrock Healthcare Capital Partners III, L.P.

    VHCP Co-Investment Holdings III, LLC

    Venrock Healthcare Capital Partners EG, L.P.

    VHCP Management III, LLC

    VHCP Management EG, LLC

    Nimish Shah

    Bong Koh

     

      (b)

    Address of Principal Business Office or, if none, Residence 

     

        New York Office: Palo Alto Office:
           
        7 Bryant Park 3340 Hillview Avenue
        23rd Floor Palo Alto, CA 94304
        New York, NY 10018  

     

      (c)

    Citizenship

     

    All of the Venrock Entities were organized in Delaware. The individuals are both United States citizens.

     
      (d)

    Title of Class of Securities

     

    Common Stock, $0.0001 par value

     
      (e)

    CUSIP Number

     

    59045L106

     

    Item 3. If this statement is filed pursuant to §§240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
       
      Not applicable

     

     

     

     

    CUSIP No. 59045L106Page 10 of 17

     

    Item 4. Ownership
       
      (a) Amount beneficially owned as of August 4, 2023:

     

    Venrock Healthcare Capital Partners III, L.P.   9,678,000 (1) 
    VHCP Co-Investment Holdings III, LLC   9,678,000 (1) 
    Venrock Healthcare Capital Partners EG, L.P.   9,678,000 (1) 
    VHCP Management III, LLC   9,678,000 (1) 
    VHCP Management EG, LLC   9,678,000 (1) 
    Nimish Shah   9,678,000 (1) 
    Bong Koh   9,678,000 (1) 

     

      (b) Percent of class as of August 4, 2023:

     

    Venrock Healthcare Capital Partners III, L.P.   8.5% (2) 
    VHCP Co-Investment Holdings III, LLC   8.5% (2) 
    Venrock Healthcare Capital Partners EG, L.P.   8.5% (2) 
    VHCP Management III, LLC   8.5% (2) 
    VHCP Management EG, LLC   8.5% (2) 
    Nimish Shah   8.5% (2) 
    Bong Koh   8.5% (2) 

     

      (c) Number of shares as to which the person has as of August 4, 2023:

     

      (i) Sole power to vote or to direct the vote:

     

    Venrock Healthcare Capital Partners III, L.P.   0 
    VHCP Co-Investment Holdings III, LLC   0 
    Venrock Healthcare Capital Partners EG, L.P.   0 
    VHCP Management III, LLC   0 
    VHCP Management EG, LLC   0 
    Nimish Shah   0 
    Bong Koh   0 

     

      (ii) Shared power to vote or to direct the vote:

     

    Venrock Healthcare Capital Partners III, L.P.   9,678,000 (1) 
    VHCP Co-Investment Holdings III, LLC   9,678,000 (1) 
    Venrock Healthcare Capital Partners EG, L.P.   9,678,000 (1) 
    VHCP Management III, LLC   9,678,000 (1) 
    VHCP Management EG, LLC   9,678,000 (1) 
    Nimish Shah   9,678,000 (1) 
    Bong Koh   9,678,000 (1) 

     

     

     

     

    CUSIP No. 59045L106Page 11 of 17

     

      (iii) Sole power to dispose or to direct the disposition of:

     

    Venrock Healthcare Capital Partners III, L.P.   0 
    VHCP Co-Investment Holdings III, LLC   0 
    Venrock Healthcare Capital Partners EG, L.P.   0 
    VHCP Management III, LLC   0 
    VHCP Management EG, LLC   0 
    Nimish Shah   0 
    Bong Koh   0 

     

      (iv) Shared power to dispose or to direct the disposition of:

     

    Venrock Healthcare Capital Partners III, L.P.   9,678,000 (1) 
    VHCP Co-Investment Holdings III, LLC   9,678,000 (1) 
    Venrock Healthcare Capital Partners EG, L.P.   9,678,000 (1) 
    VHCP Management III, LLC   9,678,000 (1) 
    VHCP Management EG, LLC   9,678,000 (1) 
    Nimish Shah   9,678,000 (1) 
    Bong Koh   9,678,000 (1) 

     

    (1)Consists of (i) 2,544,347 shares held by Venrock Healthcare Capital Partners III, L.P.; (ii) 254,531 shares held by VHCP Co-Investment Holdings III, LLC; and (iii) 6,879,122 shares held by Venrock Healthcare Capital Partners EG, L.P. VHCP Management III, LLC is the general partner of Venrock Healthcare Capital Partners III, L.P. and the manager of VHCP Co-Investment Holdings III, LLC. VHCP Management EG, LLC is the general partner of Venrock Healthcare Capital Partners EG, L.P. Messrs. Shah and Koh are the voting members of VHCP Management III, LLC and VHCP Management EG, LLC.

     

    (2)This percentage is calculated based upon 114,385,810 shares of Common Stock outstanding as of May 5, 2023, as reported in the Issuer’s Quarterly Report on Form 10-Q for the quarterly period ended March 31, 2023 filed with the Securities and Exchange Commission on May 9, 2023.

     

    Item 5. Ownership of Five Percent or Less of a Class
       
      If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five percent of the class of securities, check the following   ¨
     
    Item 6. Ownership of More than Five Percent on Behalf of Another Person
       
      Not applicable
     
    Item 7. Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on By the Parent Holding Company or Control Person
       
      Not applicable
     
    Item 8. Identification and Classification of Members of the Group
       
      Not applicable

     

     

     

     

    CUSIP No. 59045L106Page 12 of 17

     

    Item 9. Notice of Dissolution of Group
       
      Not applicable
     
    Item 10. Certification
       
      By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having such purpose or effect.

     

     

     

     

    CUSIP No. 59045L106Page 13 of 17

     

    SIGNATURE

     

    After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

     

    Dated: August 7, 2023

     

    Venrock Healthcare Capital Partners III, L.P.   Venrock Healthcare Capital Partners EG, L.P.
         
    By: VHCP Management III, LLC   By: VHCP Management EG, LLC
    Its: General Partner   Its: General Partner
         
    By: /s/ Sherman G. Souther   By: /s/ Sherman G. Souther
      Name: Sherman G. Souther     Name: Sherman G. Souther
      Its: Authorized Signatory     Its: Authorized Signatory
             
    VHCP Co-Investment Holdings III, LLC    
         
    By: VHCP Management III, LLC    
    Its: Manager    
         
    By: /s/ Sherman G. Souther    
      Name: Sherman G. Souther    
      Its: Authorized Signatory    
         
    VHCP Management III, LLC   VHCP Management EG, LLC
         
    By: /s/ Sherman G. Souther   By: /s/ Sherman G. Souther
      Name: Sherman G. Souther     Name: Sherman G. Souther
      Its: Authorized Signatory     Its: Authorized Signatory
         
    Nimish Shah    
         
    /s/ Sherman G. Souther    
    Sherman G. Souther, Attorney-in-fact    
         
    Bong Koh    
         
    /s/ Sherman G. Souther    
    Sherman G. Souther, Attorney-in-fact    

     

     

     

     

     

    CUSIP No. 59045L106Page 14 of 17

     

    EXHIBITS

     

    A:     Joint Filing Agreement

     

    B:     Power of Attorney for Nimish Shah

     

    C:     Power of Attorney for Bong Koh

     

     

     

     

    CUSIP No. 59045L106Page 15 of 17

     

    EXHIBIT A

     

    JOINT FILING AGREEMENT

     

    In accordance with Rule 13d-1(k) under the Securities Exchange Act of 1934, as amended, the undersigned agree to the joint filing on behalf of each of them of a statement on Schedule 13G (including amendments thereto) with respect to the Common Stock of Mersana Therapeutics, Inc. and further agree that this agreement be included as an exhibit to such filing. Each party to the agreement expressly authorizes each other party to file on its behalf any and all amendments to such statement. Each party to this agreement agrees that this joint filing agreement may be signed in counterparts.

     

    In evidence whereof, the undersigned have caused this Agreement to be executed on their behalf this 7th day of August, 2023.

     

    Venrock Healthcare Capital Partners III, L.P.   Venrock Healthcare Capital Partners EG, L.P.
         
    By: VHCP Management III, LLC   By: VHCP Management EG, LLC
    Its: General Partner   Its: General Partner
         
    By: /s/ Sherman G. Souther   By: /s/ Sherman G. Souther
      Name: Sherman G. Souther     Name: Sherman G. Souther
      Its: Authorized Signatory     Its: Authorized Signatory
             
    VHCP Co-Investment Holdings III, LLC    
         
    By: VHCP Management III, LLC    
    Its: Manager    
         
    By: /s/ Sherman G. Souther    
      Name: Sherman G. Souther    
      Its: Authorized Signatory    
         
    VHCP Management III, LLC   VHCP Management EG, LLC
         
    By: /s/ Sherman G. Souther   By: /s/ Sherman G. Souther
      Name: Sherman G. Souther     Name: Sherman G. Souther
      Its: Authorized Signatory     Its: Authorized Signatory
         
    Nimish Shah    
         
    /s/ Sherman G. Souther    
    Sherman G. Souther, Attorney-in-fact    
         
    Bong Koh    
         
    /s/ Sherman G. Souther    
    Sherman G. Souther, Attorney-in-fact    

     

     

     

     

    CUSIP No. 59045L106Page 16 of 17

     

    EXHIBIT B

     

    POWER OF ATTORNEY FOR NIMISH SHAH

     

    KNOW ALL BY THESE PRESENTS, that the undersigned hereby constitutes and appoints each of David L. Stepp, Sherman G. Souther and Lisa D. Harris signing individually, the undersigned’s true and lawful attorney-in fact and agent to:

     

    (i)prepare execute and file, for and on behalf of the undersigned, any and all documents and filings that are required or advisable to be made with the United States Securities and Exchange Commission, any stock exchange or similar authority, under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and the rules and regulations promulgated thereunder, including without limitation (a) any Joint Filing Agreement under Rule 13d-1(k) of the Exchange Act (or any successor provision thereunder), Schedule 13D and Schedule 13G (or any successor schedules or forms adopted under the Exchange Act ) and any amendments thereto in accordance with Section 13 of the Exchange Act and the rules thereunder, and (b) Forms 3, 4 and 5 and any amendments thereto in accordance with Section 16(a) of the Exchange Act and the rules thereunder; and

     

    (ii)take any other action of any nature whatsoever in connection with the foregoing which, in the opinion of such attorney-in-fact, may be of benefit, in the best interest of, or legally required by, the undersigned, it being understood that the documents executed by such attorney-in-fact on behalf of the undersigned pursuant to this Power of Attorney shall be in such form and shall contain such terms and conditions as such attorney-in-fact may approve in such attorney-in-fact’s discretion.

     

    The undersigned hereby grants to such attorney-in-fact full power and authority to do and perform any and every act and thing whatsoever requisite, necessary, or proper to be done in the exercise of any of the rights and powers herein granted, as fully to all intents and purposes as the undersigned might or could do if personally present, with full power of substitution or revocation, hereby ratifying and confirming all that such attorney-in-fact, or such attorney-in-fact’s substitute or substitutes, shall lawfully do or cause to be done by virtue of this power of attorney and the rights and powers herein granted. The undersigned acknowledges that the foregoing attorney-in-fact, in serving in such capacity at the request of undersigned, is not assuming, nor is Venrock assuming, any of the undersigned’s responsibilities to comply with the Exchange Act, including without limitation Sections 13 and 16 of the Exchange Act.

     

    This power of Attorney shall remain in full force and effect until the earliest to occur of (a) the undersigned is no longer required to file any form or document with respect to the undersigned’s holdings of and transactions in securities issued by a company, (b) revocation by the undersigned in a signed writing delivered to the foregoing attorney-in-fact, or (c) until such attorney-in-fact shall no longer be employed by VR Management, LLC (or its successor).

     

    IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be executed as of this 7th day of August, 2023.

     

    /s/ Nimish Shah  

     

     

     

     

    CUSIP No. 59045L106Page 17 of 17

     

    EXHIBIT C

     

    POWER OF ATTORNEY FOR BONG KOH

     

    KNOW ALL BY THESE PRESENTS, that the undersigned hereby constitutes and appoints each of David L. Stepp, Sherman G. Souther and Lisa D. Harris signing individually, the undersigned’s true and lawful attorney-in fact and agent to:

     

    (i)prepare execute and file, for and on behalf of the undersigned, any and all documents and filings that are required or advisable to be made with the United States Securities and Exchange Commission, any stock exchange or similar authority, under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and the rules and regulations promulgated thereunder, including without limitation (a) any Joint Filing Agreement under Rule 13d-1(k) of the Exchange Act (or any successor provision thereunder), Schedule 13D and Schedule 13G (or any successor schedules or forms adopted under the Exchange Act ) and any amendments thereto in accordance with Section 13 of the Exchange Act and the rules thereunder, and (b) Forms 3, 4 and 5 and any amendments thereto in accordance with Section 16(a) of the Exchange Act and the rules thereunder; and

     

    (ii)take any other action of any nature whatsoever in connection with the foregoing which, in the opinion of such attorney-in-fact, may be of benefit, in the best interest of, or legally required by, the undersigned, it being understood that the documents executed by such attorney-in-fact on behalf of the undersigned pursuant to this Power of Attorney shall be in such form and shall contain such terms and conditions as such attorney-in-fact may approve in such attorney-in-fact’s discretion.

     

    The undersigned hereby grants to such attorney-in-fact full power and authority to do and perform any and every act and thing whatsoever requisite, necessary, or proper to be done in the exercise of any of the rights and powers herein granted, as fully to all intents and purposes as the undersigned might or could do if personally present, with full power of substitution or revocation, hereby ratifying and confirming all that such attorney-in-fact, or such attorney-in-fact’s substitute or substitutes, shall lawfully do or cause to be done by virtue of this power of attorney and the rights and powers herein granted. The undersigned acknowledges that the foregoing attorney-in-fact, in serving in such capacity at the request of undersigned, is not assuming, nor is Venrock assuming, any of the undersigned’s responsibilities to comply with the Exchange Act, including without limitation Sections 13 and 16 of the Exchange Act.

     

    This power of Attorney shall remain in full force and effect until the earliest to occur of (a) the undersigned is no longer required to file any form or document with respect to the undersigned’s holdings of and transactions in securities issued by a company, (b) revocation by the undersigned in a signed writing delivered to the foregoing attorney-in-fact, or (c) until such attorney-in-fact shall no longer be employed by VR Management, LLC (or its successor).

     

    IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be executed as of this 7th day of August, 2023.

     

    /s/ Bong Koh  
       

     

     

    Get the next $MRSN alert in real time by email

    Crush Q1 2026 with the Best AI Superconnector

    Stay ahead of the competition with Standout.work - your AI-powered talent-to-startup matching platform.

    AI-Powered Inbox
    Context-aware email replies
    Strategic Decision Support
    Get Started with Standout.work

    Recent Analyst Ratings for
    $MRSN

    DatePrice TargetRatingAnalyst
    2/6/2025Outperform
    William Blair
    11/15/2024$5.00Buy
    Citigroup
    3/19/2024$5.00Underweight → Neutral
    JP Morgan
    2/29/2024$6.00Neutral → Buy
    BTIG Research
    2/29/2024$7.00Neutral → Buy
    Guggenheim
    2/29/2024$2.00 → $7.00Neutral → Outperform
    Wedbush
    12/4/2023$1.00 → $5.00Neutral → Buy
    Citigroup
    7/28/2023$7.00 → $1.00Outperform → Neutral
    Robert W. Baird
    More analyst ratings

    $MRSN
    Analyst Ratings

    Analyst ratings in real time. Analyst ratings have a very high impact on the underlying stock. See them live in this feed.

    View All

    William Blair initiated coverage on Mersana Therapeutics

    William Blair initiated coverage of Mersana Therapeutics with a rating of Outperform

    2/6/25 7:08:59 AM ET
    $MRSN
    Biotechnology: Pharmaceutical Preparations
    Health Care

    Citigroup resumed coverage on Mersana Therapeutics with a new price target

    Citigroup resumed coverage of Mersana Therapeutics with a rating of Buy and set a new price target of $5.00

    11/15/24 8:15:56 AM ET
    $MRSN
    Biotechnology: Pharmaceutical Preparations
    Health Care

    Mersana Therapeutics upgraded by JP Morgan with a new price target

    JP Morgan upgraded Mersana Therapeutics from Underweight to Neutral and set a new price target of $5.00

    3/19/24 7:51:31 AM ET
    $MRSN
    Biotechnology: Pharmaceutical Preparations
    Health Care

    $MRSN
    SEC Filings

    View All

    SEC Form 15-12G filed by Mersana Therapeutics Inc.

    15-12G - Mersana Therapeutics, Inc. (0001442836) (Filer)

    1/16/26 4:15:45 PM ET
    $MRSN
    Biotechnology: Pharmaceutical Preparations
    Health Care

    SEC Form EFFECT filed by Mersana Therapeutics Inc.

    EFFECT - Mersana Therapeutics, Inc. (0001442836) (Filer)

    1/9/26 12:15:03 AM ET
    $MRSN
    Biotechnology: Pharmaceutical Preparations
    Health Care

    SEC Form S-8 POS filed by Mersana Therapeutics Inc.

    S-8 POS - Mersana Therapeutics, Inc. (0001442836) (Filer)

    1/6/26 4:19:14 PM ET
    $MRSN
    Biotechnology: Pharmaceutical Preparations
    Health Care

    $MRSN
    Insider Trading

    Insider transactions reveal critical sentiment about the company from key stakeholders. See them live in this feed.

    View All

    Director Hack Andrew A. F. closing all direct ownership in the company (SEC Form 4)

    4 - Mersana Therapeutics, Inc. (0001442836) (Issuer)

    1/6/26 6:32:59 PM ET
    $MRSN
    Biotechnology: Pharmaceutical Preparations
    Health Care

    Director Hege Kristen closing all direct ownership in the company (SEC Form 4)

    4 - Mersana Therapeutics, Inc. (0001442836) (Issuer)

    1/6/26 4:55:45 PM ET
    $MRSN
    Biotechnology: Pharmaceutical Preparations
    Health Care

    Director Diaz Allene M. closing all direct ownership in the company (SEC Form 4)

    4 - Mersana Therapeutics, Inc. (0001442836) (Issuer)

    1/6/26 4:54:24 PM ET
    $MRSN
    Biotechnology: Pharmaceutical Preparations
    Health Care

    $MRSN
    Press Releases

    Fastest customizable press release news feed in the world

    View All

    Day One Completes Acquisition of Mersana Therapeutics

    BRISBANE, Calif., Jan. 06, 2026 (GLOBE NEWSWIRE) -- Day One Biopharmaceuticals, Inc. (NASDAQ:DAWN) ("Day One"), a biopharmaceutical company dedicated to developing and commercializing targeted therapies for people of all ages with life-threatening diseases, today announced the successful close of its acquisition of Mersana Therapeutics, Inc., (NASDAQ:MRSN) ("Mersana") following completion of all conditions of the tender offer to acquire all outstanding shares of Mersana at a price of $25 per share in cash, plus one non-tradable contingent value right ("CVR") per share to receive certain potential milestone payments of up to an aggregate of $30.25 per CVR in cash. "This acquisition of Mers

    1/6/26 9:02:10 AM ET
    $DAWN
    $MRSN
    Biotechnology: Pharmaceutical Preparations
    Health Care

    Mersana Therapeutics Provides Business Update and Announces Third Quarter 2025 Financial Results

    Day One Biopharmaceuticals, Inc. to Acquire Mersana Therapeutics, Inc.Agreement provides for upfront consideration of $25.00 per share in cash, plus potential contingent value rights cash payments of up to an aggregate of $30.25 per share, for aggregate deal value of up to approximately $285 millionClosing is expected to occur by the end of January 2026 CAMBRIDGE, Mass., Nov. 14, 2025 (GLOBE NEWSWIRE) -- Mersana Therapeutics, Inc. (NASDAQ:MRSN), a clinical-stage biopharmaceutical company focused on the development of antibody-drug conjugates (ADCs) targeting cancers in areas of high unmet medical need, today provided a business update and reported financial results for the third quarter e

    11/14/25 7:00:00 AM ET
    $MRSN
    Biotechnology: Pharmaceutical Preparations
    Health Care

    Day One Biopharmaceuticals to Acquire Mersana Therapeutics

    Agreement with Day One Biopharmaceuticals provides for upfront consideration of $25.00 per share in cash, plus potential contingent value rights cash payments of up to an aggregate of $30.25 per share, for aggregate deal value of up to approximately $285 million Closing is expected to occur by the end of January 2026 CAMBRIDGE, Mass., Nov. 13, 2025 (GLOBE NEWSWIRE) -- Mersana Therapeutics, Inc. (NASDAQ:MRSN), a clinical-stage biopharmaceutical company focused on the development of antibody-drug conjugates (ADCs) targeting cancers in areas of high unmet medical need, today announced that it has entered into a definitive merger agreement with Day One Biopharmaceuticals ("Day One"), pursua

    11/13/25 6:00:00 AM ET
    $MRSN
    Biotechnology: Pharmaceutical Preparations
    Health Care

    $MRSN
    Leadership Updates

    Live Leadership Updates

    View All

    Mersana Therapeutics Announces Changes in Leadership

    Anna Protopapas to retire as President and Chief Executive Officer (CEO); will remain a member of the Board of DirectorsMartin Huber, M.D., current member of the Board of Directors, to be named President and CEOBrian DeSchuytner named Chief Operating Officer; Mohan Bala, Ph.D., named Chief Development Officer CAMBRIDGE, Mass., Sept. 06, 2023 (GLOBE NEWSWIRE) -- Mersana Therapeutics, Inc. (NASDAQ:MRSN), a clinical-stage biopharmaceutical company focused on discovering and developing a pipeline of antibody-drug conjugates (ADCs) targeting cancers in areas of high unmet medical need, today announced the retirement of Anna Protopapas, President and CEO, effective September 10, 2023, and the

    9/6/23 7:00:40 AM ET
    $MRSN
    Biotechnology: Pharmaceutical Preparations
    Health Care

    Mersana Therapeutics Provides Statement About SVB

    CAMBRIDGE, Mass., March 10, 2023 (GLOBE NEWSWIRE) -- Mersana Therapeutics, Inc. (NASDAQ:MRSN), a clinical-stage biopharmaceutical company focused on discovering and developing a pipeline of antibody-drug conjugates (ADCs) targeting cancers in areas of high unmet medical need, today provided an update about its capital resources. A de minimis amount of Mersana's capital is currently held in a checking account at Silicon Valley Bank (SVB). The balance of the company's capital resources is held in a custodial account managed by another institution and in money market funds of institutions other than SVB. Mersana has a loan and security agreement with Oxford Finance LLC and SVB. As previously

    3/10/23 7:10:38 PM ET
    $MRSN
    Biotechnology: Pharmaceutical Preparations
    Health Care

    Mersana Therapeutics Announces Appointment of Mohan Bala, Ph.D., as SVP, Strategic Product Planning & Program Leadership

    CAMBRIDGE, Mass., Oct. 25, 2021 (GLOBE NEWSWIRE) -- Mersana Therapeutics, Inc. (NASDAQ:MRSN), a clinical-stage biopharmaceutical company focused on discovering and developing a pipeline of antibody-drug conjugates (ADCs) targeting cancers in areas of high unmet medical need, today announced the appointment of Mohan Bala, Ph.D., as SVP, Strategic Product Planning & Program Leadership, effective Monday, October 25, 2021. Dr. Bala will assume strategic product planning responsibilities from Brian DeSchuytner who has been named SVP and Chief Financial Officer. Mr. DeSchuytner will continue to lead finance, business development, corporate strategy and investor relations and remain Mersana's pri

    10/25/21 8:00:00 AM ET
    $MRSN
    Biotechnology: Pharmaceutical Preparations
    Health Care

    $MRSN
    Financials

    Live finance-specific insights

    View All

    $MRSN
    Large Ownership Changes

    This live feed shows all institutional transactions in real time.

    View All

    Mersana Therapeutics Provides Business Update and Announces Third Quarter 2025 Financial Results

    Day One Biopharmaceuticals, Inc. to Acquire Mersana Therapeutics, Inc.Agreement provides for upfront consideration of $25.00 per share in cash, plus potential contingent value rights cash payments of up to an aggregate of $30.25 per share, for aggregate deal value of up to approximately $285 millionClosing is expected to occur by the end of January 2026 CAMBRIDGE, Mass., Nov. 14, 2025 (GLOBE NEWSWIRE) -- Mersana Therapeutics, Inc. (NASDAQ:MRSN), a clinical-stage biopharmaceutical company focused on the development of antibody-drug conjugates (ADCs) targeting cancers in areas of high unmet medical need, today provided a business update and reported financial results for the third quarter e

    11/14/25 7:00:00 AM ET
    $MRSN
    Biotechnology: Pharmaceutical Preparations
    Health Care

    Mersana Therapeutics to Host Third Quarter 2025 Conference Call on November 14, 2025

    CAMBRIDGE, Mass., Nov. 10, 2025 (GLOBE NEWSWIRE) -- Mersana Therapeutics, Inc. (NASDAQ:MRSN), a clinical-stage biopharmaceutical company focused on the development of antibody-drug conjugates (ADCs) targeting cancers in areas of high unmet medical need, today announced that it will provide business updates and report its financial results for the third quarter ended September 30, 2025 on Friday, November 14, 2025. The company will host a conference call and webcast at 8:00 a.m. Eastern Time that morning. To access the call, please dial 833-255-2826 (domestic) or 412-317-0689 (international). A live webcast of the presentation will be available on the Investors & Media section of the Mersa

    11/10/25 8:00:00 AM ET
    $MRSN
    Biotechnology: Pharmaceutical Preparations
    Health Care

    Mersana Therapeutics Provides Business Update and Announces Second Quarter 2025 Financial Results

    More than 45 patients enrolled in Emi-Le Phase 1 dose expansion cohorts in post-topoisomerase-1 inhibitor ADC (post-topo-1) triple-negative breast cancer (TNBC)Plan to report initial clinical data from Emi-Le expansion cohorts in second half of 2025Conference call today at 8:00 a.m. ET CAMBRIDGE, Mass., Aug. 13, 2025 (GLOBE NEWSWIRE) -- Mersana Therapeutics, Inc. (NASDAQ:MRSN), a clinical-stage biopharmaceutical company focused on the development of antibody-drug conjugates (ADCs) targeting cancers in areas of high unmet medical need, today provided a business update and reported financial results for the second quarter ended June 30, 2025. "During the second quarter, we were excited to

    8/13/25 7:00:00 AM ET
    $MRSN
    Biotechnology: Pharmaceutical Preparations
    Health Care

    Amendment: SEC Form SC 13D/A filed by Mersana Therapeutics Inc.

    SC 13D/A - Mersana Therapeutics, Inc. (0001442836) (Subject)

    11/15/24 4:45:57 PM ET
    $MRSN
    Biotechnology: Pharmaceutical Preparations
    Health Care

    Amendment: SEC Form SC 13G/A filed by Mersana Therapeutics Inc.

    SC 13G/A - Mersana Therapeutics, Inc. (0001442836) (Subject)

    11/14/24 5:45:55 PM ET
    $MRSN
    Biotechnology: Pharmaceutical Preparations
    Health Care

    Amendment: SEC Form SC 13G/A filed by Mersana Therapeutics Inc.

    SC 13G/A - Mersana Therapeutics, Inc. (0001442836) (Subject)

    11/14/24 6:01:51 AM ET
    $MRSN
    Biotechnology: Pharmaceutical Preparations
    Health Care