Washington, D.C. 20549


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 Number: 3235-0104
Estimated average burden
hours per response: 0.5
1. Name and Address of Reporting Person*

(Last) (First) (Middle)


(City) (State) (Zip)
2. Date of Event Requiring Statement (Month/Day/Year)
3. Issuer Name and Ticker or Trading Symbol
4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
Director 10% Owner
X Officer (give title below) Other (specify below)
V.P.-Fin., Prin. Acctg. Off.
5. If Amendment, Date of Original Filed (Month/Day/Year)
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 Beneficially Owned
1. Title of Security (Instr. 4) 2. Amount of Securities Beneficially Owned (Instr. 4) 3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common Stock 2,000 D
Table II - Derivative Securities Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4) 2. Date Exercisable and Expiration Date (Month/Day/Year) 3. Title and Amount of Securities Underlying Derivative Security (Instr. 4) 4. Conversion or Exercise Price of Derivative Security 5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 6. Nature of Indirect Beneficial Ownership (Instr. 5)
Date Exercisable Expiration Date Title Amount or Number of Shares
Stock Option (Right to buy) 07/24/2010(1) 07/24/2019 Common Stock 3,354 9.88 D
Stock Option (Right to buy) 07/23/2011(1) 07/23/2020 Common Stock 12,500 9.14 D
Stock Option (Right to buy) 07/22/2012(1) 07/22/2021 Common Stock 16,000 15.2 D
Stock Option (Right to buy) 07/20/2013(1) 07/20/2022 Common Stock 16,050 15.83 D
Stock Option (Right to buy) 07/16/2014(1) 07/16/2023 Common Stock 15,000 19.02 D
Stock Option (Right to buy) 07/17/2015(1) 07/17/2024 Common Stock 16,500 10.79 D
Stock Option (Right to buy) 07/13/2016(1) 07/13/2025 Common Stock 15,000 16.72 D
Stock Option (Right to buy) 07/18/2017(2) 07/18/2026 Common Stock 20,000 3.05 D
Stock Option (Right to buy) 02/21/2018(2) 02/21/2027 Common Stock 12,000 2.47 D
Stock Option (Right to buy) 02/15/2019(2) 02/15/2028 Common Stock 28,000 10.65 D
Stock Option (Right to buy) 09/12/2019(3) 09/12/2028 Common Stock 29,050 9.35 D
Explanation of Responses:
1. All options are exercisable as of the filing date of this Form 3.
2. Exercisable in three equal installments over three years starting on the first year anniversary of the grant.
3. Exercisable in four equal installments over four years starting on the first year anniversary of the grant.
/s/ David Foster 09/20/2018
** 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 5 (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).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

KNOW ALL BY THESE PRESENT, that the undersigned hereby constitutes 
and appoints Craig Barrows
of ImmunoGen, Inc. (the "Company"), acting singly, with full power of 
substitution, the undersigned's true and lawful attorney-in-fact to:

(1) Execute for and on behalf of the undersigned, in the 
undersigned's capacity as an officer, director and/or 10% 
shareholder of the Company, Forms 3, 4 and 5, and amendments thereto,
in accordance with Section 16(a) of the Securities Exchange Act of 1934 
and the rules thereunder;

(2) Do and perform any and all acts for and on behalf of 
the undersigned which may be necessary or desirable to 
complete and 
execute any such Form 3, 4 or 5, or amendments thereto, and timely file 
such form with 
the United States Securities and Exchange Commission and 
any stock 
exchange or similar authority; and

(3) Take any other action of any type whatsoever in connection 
the foregoing which, in the opinion of such attorney-in-fact, 
be of benefit to, in the best interest of, or legally required 
the undersigned, it being understood that the documents executed 
by such attorney-in-fact on behalf of the undersigned pursuant 
to this Power of Attorney shall be in such form and shall 
contain such terms
 and conditions as such attorney-in-fact 
may approve in such attorney-in-fact's discretion.

The undersigned hereby grants to each such attorney-in-fact 
power and authority to do and perform any and every act and 
thing whatsoever requisite, necessary, or proper to be done 
in the 
exercise of the rights and powers herein granted, as fully 
to all intents and purposes as the undersigned might or 
could do if 
personally present, with full power of substitution or 
revocation, hereby ratifying and confirming all that such attorney-in-fact, or 
such attorney-in-fact's substitute or substitutes, shall 
do or cause to be done by virtue of this Power of Attorney 
and the rights and powers herein granted.  The undersigned 
acknowledges that the foregoing attorneys-in-fact, in serving 
in such capacity at the request of the undersigned, are not 
assuming, nor is the Company assuming, any of the 
undersigned's responsibilities to comply with Section 16 of the Securities 
Exchange Act of 1934.

The undersigned agrees that each such attorney-in-fact shall not be liable for 
any error of judgment or for any act done or omitted to be done or for any 
mistake of fact or law except for each such attorney-in-fact's own bad faith, 
and the 
undersigned agrees to indemnify and to hold each such attorney-in-fact harmless
against any loss, claim, damage, liability or cost incurred on each such 
attorney-in-fact's part arising out of or in connection with acts undertaken or
omitted to be taken as an attorney-in-fact hereunder.
This Power of Attorney shall remain in full force and effect until 
the undersigned is no longer required to file Forms 3, 4 and 
5 with respect to the undersigned's holdings of and 
transactions in 
securities issued by the Company, unless earlier revoked 
by the undersigned in a signed writing delivered to the 
foregoing attorneys-in-fact.

IN WITNESS WHEREOF, the undersigned has caused this Power of 
Attorney to be executed this 14th day of September 2018.

/s/ David G. Foster
Print Name: David G. Foster