This License Agreement ("Agreement") is made effective as of May 2, 2000 (the "Effective Date") by and
between GENENTECH, INC., a Delaware corporation having its principal business office at 1 DNA Way,
South San Francisco, California 94080 ("GENENTECH"), and IMMUNOGEN, INC., a Massachusetts
corporation with its principal place of business at 333 Providence Highway, Norwood, Massachusetts 02062
("IMMUNOGEN"). GENENTECH and IMMUNOGEN are each hereafter referred to individually as a "Party"
and together as the "Parties".
WHEREAS, GENENTECH is the owner of or otherwise controls certain rights in proprietary technology and
know-how relating to anti-HER2 antibodies and other HER-2 binding proteins; and
WHEREAS, IMMUNOGEN is the owner of or otherwise controls certain rights in proprietary technology and
know-how relating to or otherwise useful in the conjugation of maytansine derivatives such as DM1 to binding
WHEREAS, pursuant to an MTA (as defined below), IMMUNOGEN performed certain work using a biologic
materials of GENENTECH to create a conjugated compound, which work under the MTA is part of what is
covered by this Agreement; and
WHEREAS, on the terms and conditions set forth herein, GENENTECH desires to obtain from
IMMUNOGEN, and IMMUNOGEN desires to grant to GENENTECH, the rights set forth herein, including a
license under IMMUNOGEN'S technology and/or intellectual property rights to develop and commercialize one
or more Licensed Products (as defined below).
NOW, THEREFORE, in consideration of the mutual covenants contained herein, and for other good and
valuable consideration, the receipt and adequacy of which are hereby acknowledged, the Parties hereby agree as
Whenever used in the Agreement with an initial capital letter, the terms defined in this Section 1 shall have the
1.1. "ADVERSE EVENT" shall mean any untoward medical occurrence in a patient or subject who is