Ownership Submission
FORM 3
 UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
  Ryll Thomas
 2. Date of Event Requiring Statement (Month/Day/Year)
03/29/2017		 3. Issuer Name and Ticker or Trading Symbol
IMMUNOGEN INC [IMGN]
(Last)
(First)
(Middle)
C/O IMMUNOGEN, INC., 830 WINTER STREET		 4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
VP, Technical Operations
 5. If Amendment, Date Original Filed(Month/Day/Year)
(Street)

WALTHAM, MA 02451		 6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
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 106,600 (5)
D
 
Common Stock 1,500
D
 

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly. SEC 1473 (7-02)
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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 of Derivative Security: 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) 08/17/2016(1) 08/17/2025 Common Stock 60,000 $ 14.56 D  
Stock Option (right to buy) 06/01/2017(2) 06/01/2026 Common Stock 4,000 $ 5.75 D  
Stock Option (right to buy) 07/18/2017(3) 07/18/2026 Common Stock 40,000 $ 3.05 D  
Stock Option (right to buy) 09/30/2017(4) 09/30/2026 Common Stock 38,000 $ 2.68 D  

Reporting Owners

Reporting Owner Name / Address Relationships
Director 10% Owner Officer Other
Ryll Thomas
C/O IMMUNOGEN, INC.
830 WINTER STREET
WALTHAM, MA 02451		       VP, Technical Operations  

Signatures

/s/ Craig Barrows, attorney in fact 04/06/2017
**Signature of Reporting Person Date

Explanation of Responses:

* 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).
(1) 15,000 shares exercisable as of filing date, 15,000 shares exercisable commencing on August 17, 2017, 15,000 shares exercisable commencing on August 17, 2018 and 15,000 shares exercisable commencing on August 17, 2019.
(2) Exercisable as to 1,334 shares commencing on June 1, 2017, 1,333 shares exercisable commencing on June 1, 2018, and 1,334 shares exercisable commencing on June 1, 2019.
(3) Exercisable as to 13,334 shares commencing on July 18, 2017, 13,333 shares commencing on July 18, 2018, and 13,333 shares commencing on July 18, 2019.
(4) Exercisable as to 12,667 shares commencing on September 30, 2017, 12,667 shares commencing on September 30, 2018, and 12,666 shares commencing on September 30, 2019.
(5) These shares are restricted stock which vest annually in three equal installments commencing on February 21, 2018.

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