SEC Form 4

FORM 4		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
X	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* BLATTLER WALTER (Last) (First) (Middle) C/O IMMUNOGEN, INC. 128 SIDNEY STREET (Street) CAMBRIDGE MA 02139 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol IMMUNOGEN INC [ IMGN ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director 10% Owner Officer (give title below) X Other (specify below) Executive Vice President / Former Executive VP
	3. Date of Earliest Transaction (Month/Day/Year) 03/23/2007
	4. If Amendment, Date of Original Filed (Month/Day/Year) 03/27/2007	6. Individual or Joint/Group Filing (Check Applicable Line) X Form filed by One Reporting Person Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	03/23/2007		M		138,949	A	$0.844	263,849	D
Common Stock	03/23/2007		M		109,683	A	$3.95	373,532	D
Common Stock	03/23/2007		M		23,868	A	$3.91	397,400	D
Common Stock	03/23/2007		S		117,531	D	$4.7	279,869	D
Common Stock	03/23/2007		S		5,900	D	$4.71	273,969	D
Common Stock	03/23/2007		S		33,336	D	$4.72	240,633	D
Common Stock	03/23/2007		S		1,929	D	$4.73	238,704	D
Common Stock	03/23/2007		S		4,656	D	$4.74	234,048	D
Common Stock	03/23/2007		S		4,200	D	$4.7435	229,848	D
Common Stock	03/23/2007		S		91,356	D	$4.75	138,492	D
Common Stock	03/23/2007		S		724	D	$4.76	137,768	D
Common Stock	03/23/2007		S		523	D	$4.77	137,245	D
Common Stock	03/23/2007		S		300	D	$4.78	136,945	D
Common Stock	03/23/2007		S		10,945	D	$4.8	126,000	D
Common Stock	03/23/2007		S		100	D	$4.81	125,900	D
Common Stock	03/23/2007		S		1,000	D	$4.85	124,900	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Non-qualified Stock Option	$0.844	03/23/2007		M			138,949	12/31/1998(1)(4)	12/31/2007	Common Stock	138,949	$0.844	0	D
Non-qualified Stock Option	$3.95	03/23/2007		M			109,683	06/05/2003(2)	06/05/2012	Common Stock	109,683	$3.95	0	D
Non-qualified Stock Option	$3.91	03/23/2007		M			23,868	06/12/2004(3)(4)	06/12/2013	Common Stock	23,868	$3.91	35,557	D

Explanation of Responses:

1. Exercisable as to 53,473 shares on December 31, 1998, 53,472 shares exercisable on December 31, 1999, and 53,472 shares exercisable on December 31, 2000.

2. Exercisable as to 45,000 shares on June 5, 2003, 44,999 shares exercisable on June 5, 2004, and 19,684 shares exercisable on June 5, 2005.

3. Exercisable as to 28,334 shares on June 12, 2004, 28,333 shares exercisable on June 12, 2005, and 2,758 shares exercisable on June 12, 2006.

4. This Form 4A is being filed to correct for footnotes inadvertantly misstated and omitted from the orginal Form 4 filed on March 27, 2007.

	/s/ Walter Blattler	04/05/2007
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
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