Exhibit 10.4(a)

 

AMENDMENT TO
LICENSE AGREEMENT

 

This Amendment (“Amendment”) is made as of the 23rd day of October, 1998, by and
between Pharmacia & Upjohn AB, a corporation organized and existing under the
laws of Sweden with an operating office at Lindhagensgatan 133, SE-11287
Stockholm, Sweden (“P&U”); and ImmunoGen, Inc., a Massachusetts corporation with
an operating office at 333 Providence Highway, Norwood, Massachusetts 02062, USA
(“ImmunoGen”).

 

WHEREAS, the parties hereto desire to amend the License Agreement between P&U
and ImmunoGen dated as of June 1, 1998 (the “Agreement”).

 

NOW THEREFORE, for good and valuable consideration, the receipt and sufficiency
of which is hereby acknowledged, the parties hereto hereby agree as follows:

 

1.                                      DEFINITIONS

 

Capitalized terms not otherwise defined herein shall have the respective
meanings ascribed to them in the Agreement.

 

2.                                      AMENDMENTS

 

2.1                                 The Agreement is hereby amended by adding as
Section 1.9 a definition of “C242” as follows:

 

“C242” shall mean any antibody or fragment thereof which binds to the same
epitope as the antibody produced by hybridoma cell line C242:II, which cell line
has ECACC identification number 90012601.

 

2.2                                 The Agreement is hereby amended by adding as
Section 1.10 a definition of “May” as follows:

 

“May” shall mean any maytansinoid drug, including, but not limited to,
maytansine and DM1, whether produced by natural fermentation or chemical
synthesis.

 

2.3                                 The Agreement is hereby amended by revising
the definition of “Field” in Section 1.2 to mean “the palliative, therapeutic or
prophylactic treatment of human disease.”

 

2.4                                 The Agreement is hereby amended by revising
the definition of “Licensed Product” in Section 1.4 to mean “a
C242-May conjugate.”

 

2.5                                 The Agreement is hereby amended by inserting
in Section 2.1(a) the words “which are or may be” prior to “useful in the Field”
in the sixth line.

 

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2.6                                 The Agreement is hereby amended by replacing
in Section 6.1(a) the words “fifteen (15)” with “thirty (30)” in the second
line, and by replacing in Section 6.1(a) the words “sixty (60)” with “ninety
(90)” in the fourth line.

 

2.7                                 The Agreement is hereby amended by adding
the following words to the last sentence of Section 6.4: “, and in no event
shall the obligations of any such Sublicensee under any such written agreement
be greater than the obligations of IMMUNOGEN to P&U set forth herein.”

 

3.                                      EFFECT

 

Except as amended hereby, the Agreement remains in full force and effect.

 

IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be executed
under seal as of the date first written above by their respective officers
thereunto duly authorized.

 

 

IMMUNOGEN, INC.

 

 

By:

/s/ Mitchel Sayare

 

 

 

PHARMACIA & UPJOHN AB

 

 

By:

/s/ [ILLEGIBLE]

 

 

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