    <SEC-DOCUMENT>0001104659-22-052704-index.html : 20220429
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    <ACCEPTANCE-DATETIME>20220429060735
    ACCESSION NUMBER:		0001104659-22-052704
    CONFORMED SUBMISSION TYPE:	DEF 14A
    PUBLIC DOCUMENT COUNT:		8
    CONFORMED PERIOD OF REPORT:	20220609
    FILED AS OF DATE:		20220429
    DATE AS OF CHANGE:		20220429

    FILER:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			Mersana Therapeutics, Inc.
    		CENTRAL INDEX KEY:			0001442836
    		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
    		IRS NUMBER:				000000000
    		STATE OF INCORPORATION:			DE
    		FISCAL YEAR END:			1231

    	FILING VALUES:
    		FORM TYPE:		DEF 14A
    		SEC ACT:		1934 Act
    		SEC FILE NUMBER:	001-38129
    		FILM NUMBER:		22869848

    	BUSINESS ADDRESS:
    		STREET 1:		840 MEMORIAL DRIVE
    		CITY:			CAMBRIDGE
    		STATE:			MA
    		ZIP:			02139
    		BUSINESS PHONE:		617-498-0020

    	MAIL ADDRESS:
    		STREET 1:		840 MEMORIAL DRIVE
    		CITY:			CAMBRIDGE
    		STATE:			MA
    		ZIP:			02139

    	FORMER COMPANY:
    		FORMER CONFORMED NAME:	MERSANA THERAPEUTICS INC
    		DATE OF NAME CHANGE:	20080813
    </SEC-HEADER>
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    <TYPE>DEF 14A
    <SEQUENCE>1
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    <DESCRIPTION>DEF 14A
    <TEXT>
    Document 1 - file: tm223478-2_def14a.htm

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    <TEXT>
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    <TEXT>
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    <DESCRIPTION>GRAPHIC
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    <SEQUENCE>7
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    <TEXT>
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    <SEQUENCE>8
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    <DESCRIPTION>GRAPHIC
    <TEXT>
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