<SEC-DOCUMENT>0001144204-17-008851-index.html : 20170214
<SEC-HEADER>0001144204-17-008851.hdr.sgml : 20170214
<ACCEPTANCE-DATETIME>20170214162716
ACCESSION NUMBER:		0001144204-17-008851
CONFORMED SUBMISSION TYPE:	SC 13G/A
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20170214
DATE AS OF CHANGE:		20170214
GROUP MEMBERS:		BAKER BROS. ADVISORS (GP) LLC
GROUP MEMBERS:		FELIX J. BAKER
GROUP MEMBERS:		JULIAN C. BAKER

SUBJECT COMPANY:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			IMMUNOGEN INC
		CENTRAL INDEX KEY:			0000855654
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				042726691
		STATE OF INCORPORATION:			MA
		FISCAL YEAR END:			0630

	FILING VALUES:
		FORM TYPE:		SC 13G/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-40774
		FILM NUMBER:		17609144

	BUSINESS ADDRESS:	
		STREET 1:		830 WINTER ST
		CITY:			WALTHAM
		STATE:			MA
		ZIP:			02451
		BUSINESS PHONE:		(781)895-0600

	MAIL ADDRESS:	
		STREET 1:		830 WINTER ST
		CITY:			WALTHAM
		STATE:			MA
		ZIP:			02451

FILED BY:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			BAKER BROS. ADVISORS LP
		CENTRAL INDEX KEY:			0001263508
		IRS NUMBER:				134093645
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13G/A

	BUSINESS ADDRESS:	
		STREET 1:		667 MADISON AVE
		STREET 2:		21ST FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10065
		BUSINESS PHONE:		2123395600

	MAIL ADDRESS:	
		STREET 1:		667 MADISON AVE
		STREET 2:		21ST FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10065

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	BAKER BROS ADVISORS LLC
		DATE OF NAME CHANGE:	20030911
</SEC-HEADER>
<DOCUMENT>
<TYPE>SC 13G/A
<SEQUENCE>1
<FILENAME>v459162_sc13ga.htm
<DESCRIPTION>SC 13G/A
<TEXT>
Document 1 - file: v459162_sc13ga.htm

</DOCUMENT>
</SEC-DOCUMENT>