<SEC-DOCUMENT>0001104659-20-137461-index.html : 20201218
<SEC-HEADER>0001104659-20-137461.hdr.sgml : 20201218
<ACCEPTANCE-DATETIME>20201218164522
ACCESSION NUMBER:		0001104659-20-137461
CONFORMED SUBMISSION TYPE:	S-3ASR
PUBLIC DOCUMENT COUNT:		8
FILED AS OF DATE:		20201218
DATE AS OF CHANGE:		20201218
EFFECTIVENESS DATE:		20201218

FILER:

	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:			1231

	FILING VALUES:
		FORM TYPE:		S-3ASR
		SEC ACT:		1933 Act
		SEC FILE NUMBER:	333-251502
		FILM NUMBER:		201401142

	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

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	IMMUNOGEN INC
		DATE OF NAME CHANGE:	19920703
</SEC-HEADER>
<DOCUMENT>
<TYPE>S-3ASR
<SEQUENCE>1
<FILENAME>tm2038486-6_s3asr.htm
<DESCRIPTION>S-3ASR
<TEXT>
Document 1 - file: tm2038486-6_s3asr.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-4.7
<SEQUENCE>2
<FILENAME>tm2038486d2_ex4-7.htm
<DESCRIPTION>EXHIBIT 4.7
<TEXT>
Document 2 - file: tm2038486d2_ex4-7.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-4.8
<SEQUENCE>3
<FILENAME>tm2038486d2_ex4-8.htm
<DESCRIPTION>EXHIBIT 4.8
<TEXT>
Document 3 - file: tm2038486d2_ex4-8.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-5.1
<SEQUENCE>4
<FILENAME>tm2038486d2_ex5-1.htm
<DESCRIPTION>EXHIBIT 5.1
<TEXT>
Document 4 - file: tm2038486d2_ex5-1.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-23.1
<SEQUENCE>5
<FILENAME>tm2038486d2_ex23-1.htm
<DESCRIPTION>EX-23.1
<TEXT>
Document 5 - file: tm2038486d2_ex23-1.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>6
<FILENAME>lg_immunogen-4c.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 6 - file: lg_immunogen-4c.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>7
<FILENAME>tm2038486d2_ex5-1img001.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 7 - file: tm2038486d2_ex5-1img001.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>8
<FILENAME>tm2038486d2_ex5-1img002.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 8 - file: tm2038486d2_ex5-1img002.jpg

</DOCUMENT>
</SEC-DOCUMENT>