SCHEDULE 13G

Amendment No. 1
Immunogen Incorporated
common stock
Cusip # 45253H101
Filing Fee: No


Cusip # 45253H101
Item 1:   Reporting Person - FMR Corp. - (Tax ID:  04-2507163)
Item 4:   Commonwealth of Massachusetts
Item 5:   None
Item 6:   None
Item 7:   78,000
Item 8:   None
Item 9:   78,000
Item 11:  0.74%
Item 12:  HC 




Cusip # 45253H101
Item 1:   Reporting Person - Edward C. Johnson 3d - (Tax ID:  ###-##-####)
Item 4:   United States of America
Item 5:   None
Item 6:   None
Item 7:   78,000
Item 8:   None
Item 9:   78,000
Item 11:  0.74%
Item 12:  IN 




SCHEDULE 13G - TO BE INCLUDED IN STATEMENTS
FILED PURSUANT TO RULE 13d-1(b) or 13d-2(b)


Item 1(a).    Name of Issuer:

         Immunogen Incorporated

Item 1(b).    Name of Issuer's Principal Executive Offices:

         60 Hamilton Street
         Cambridge, MA  02139

Item 2(a).    Name of Person Filing: 

         FMR Corp.

Item 2(b).    Address or Principal Business Office or, if None, Residence:

         82 Devonshire Street, Boston, Massachusetts  02109

Item 2(c).    Citizenship:

         Not applicable

Item 2(d).    Title of Class of Securities:

         common stock

Item 2(e).    CUSIP Number:  

         45253H101

Item 3.  This statement is filed pursuant to Rule 13d-1(b) or 13d-2(b) and the
person filing, FMR Corp., is a parent holding company in accordance
with Section 240.13d-1(b)(ii)(G).  (Note:  See Item 7).

Item 4.  Ownership

         (a)  Amount Beneficially Owned:    78,000

         (b)  Percent of Class:   0.74%

         (c)  Number of shares as to which such person has:  

              (i)   sole power to vote or to direct the vote:   None

              (ii)  shared power to vote or to direct the vote: None

              (iii) sole power to dispose or to direct the disposition of:
    78,000

              (iv)  shared power to dispose or to direct the disposition
of: None




Item 5.  Ownership of Five Percent or Less of a Class.

         If this statement is being filed to report the fact that as
of the date hereof, the reporting person has ceased to be
the beneficial owner of more than five percent of the class
of securities, check the following (X).

Item 6.  Ownership of More than Five Percent on Behalf of Another Person.

         Not applicable.

Item 7.  Identification and Classification of the Subsidiary Which Acquired
the Security Being Reported on By the Parent Holding Company.

         See attached Exhibit(s) A and B.

Item 8.  Identification and Classification of Members of the Group.

         Not applicable, see attached Exhibit A. 

Item 9.  Notice of Dissolution of Group.

         Not applicable.


Item 10. Certification.

         Inasmuch as the reporting persons are no longer the beneficial
owners of more than 5% of the number of shares outstanding, the
reporting persons have no further reporting obligation under
section 13(d) of the Securities and Exchange Commission
thereunder, and the reporting persons have no obligation to amend
this Statement if any material change occurs in the facts set
forth herein.


Signature

         After reasonable inquiry and to the best of my knowledge and
belief, I certify that the information set forth in this statement
is true, complete and correct. 



    February 11, 1994   
Date



    /S/Arthur S. Loring
Signature



    Arthur S. Loring, Vice President
    
Name/Title




SCHEDULE 13G - TO BE INCLUDED IN STATEMENTS
FILED PURSUANT TO RULE 13d-1(b) or 13d-2(b)

    Pursuant to the instructions in Item 7 of Schedule 13G, Fidelity
Management & Research Company ("Fidelity"), 82 Devonshire Street, Boston,
Massachusetts 02109, a wholly-owned subsidiary of FMR Corp. and an
investment adviser registered under Section 203 of the Investment Advisers
Act of 1940, is the beneficial owner of 78,000 shares or 0.74% of the
common stock outstanding of Immunogen Incorporated ("the Company") as a
result of acting as investment adviser to several investment companies
registered under Section 8 of the Investment Company Act of 1940.  

    Edward C. Johnson 3d, FMR Corp., through its control of Fidelity, and
the Funds each has sole power to dispose of the 78,000 shares owned by the
Funds.

    Neither FMR Corp. nor Edward C. Johnson 3d, Chairman of FMR Corp., 
has the sole power to vote or direct the voting of the Shares owned
directly by the Fidelity Funds, which power resides with the Funds' Boards
of Trustees.  Fidelity carries out the voting of the Shares under written
guidelines established by the Funds' Boards of Trustees.

    Edward C. Johnson 3d owns 34.0% of the outstanding voting common stock
of FMR Corp.  Mr. Johnson 3d is Chairman of FMR Corp.  Various Johnson
family members and trusts for the benefit of Johnson family members own FMR
Corp. voting common stock.  These Johnson family members, through their
ownership of voting common stock, form a controlling group with respect to
FMR Corp.



SCHEDULE 13G - TO BE INCLUDED IN STATEMENTS
FILED PURSUANT TO RULE 13d-1(b) or 13d-2(b)

RULE 13d-1(e)  AGREEMENT

    The undersigned persons, on February 11, 1994, agree and consent to
the joint filing on their behalf of this Schedule 13G in connection with
their beneficial ownership of the common stock of Immunogen Incorporated at
December 31, 1993.

    FMR Corp.
    By   /S/Arthur S. Loring
Arthur S. Loring
Vice President - Legal
         Edward C. Johnson 3d
    By   /S/Arthur S. Loring
Arthur S. Loring
Under Power of Attorney
dated 5/17/89
On File with Schedule 13G
for
Airborne Freight Corp.
9/10/91
    Fidelity Management & Research Company
    By   /S/Arthur S. Loring
Arthur S. Loring
Sr. V.P. and General
Counsel