<SEC-DOCUMENT>0000921895-21-000331-index.html : 20210211
<SEC-HEADER>0000921895-21-000331.hdr.sgml : 20210211
<ACCEPTANCE-DATETIME>20210211170822
ACCESSION NUMBER:		0000921895-21-000331
CONFORMED SUBMISSION TYPE:	SC 13G/A
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20210211
DATE AS OF CHANGE:		20210211

SUBJECT COMPANY:	

	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:		SC 13G/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-90033
		FILM NUMBER:		21620801

	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

FILED BY:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			BIOTECHNOLOGY VALUE FUND L P
		CENTRAL INDEX KEY:			0000918923
		STANDARD INDUSTRIAL CLASSIFICATION:	INVESTMENT ADVICE [6282]
		IRS NUMBER:				363924731
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13G/A

	BUSINESS ADDRESS:	
		STREET 1:		44 MONTGOMERY STREET
		STREET 2:		40TH FL
		CITY:			SAN FRANCISCO
		STATE:			CA
		ZIP:			94104
		BUSINESS PHONE:		3125066500

	MAIL ADDRESS:	
		STREET 1:		44 MONTGOMERY STREET
		STREET 2:		40TH FL
		CITY:			SAN FRANCISCO
		STATE:			CA
		ZIP:			94104
</SEC-HEADER>
<DOCUMENT>
<TYPE>SC 13G/A
<SEQUENCE>1
<FILENAME>sc13ga307422mrsn_02052021.htm
<DESCRIPTION>AMENDMENT NO. 3 TO THE SCHEDULE 13G
<TEXT>
Document 1 - file: sc13ga307422mrsn_02052021.htm

</DOCUMENT>
</SEC-DOCUMENT>