CONFIDENTIAL MATERIALS OMITTED AND FILED SEPARATELY WITH THE
SECURITIES AND EXCHANGE COMMISSION.
ASTERISKS DENOTE SUCH OMISSIONS.
This Sublease Agreement (this "Sublease") is made on this 16 day of July, 2002 between Antigenics, Inc., a
Massachusetts Corporation, with an address of 34 Commerce Way, Woburn, Massachusetts 01801 a wholly-
owned subsidiary of Antigenics Inc., a Delaware corporation formerly known as Aquila Biopharmaceuticals, Inc.
("Sublessor") and GTC Biotherapeutics, Inc., a Massachusetts corporation with an address of 175 Crossing
Boulevard, Suite 410, Framingham, Massachusetts ("Sublessee").
WHEREAS, Aquila Biopharmaceuticals, Inc., a Delaware corporation and wholly owned subsidiary of
Sublessor, is the tenant under a lease with NDNE 9/90 Corporate Center LLC (the "Prime Lessor") dated
September 19, 1997 as amended by that certain First Amendment to Lease ("First Amendment") dated
December 17, 1997, as further amended by that certain Second Amendment to Lease ("Second Amendment")
dated as of January 14, 1998, as further amended by that certain Third Amendment to Lease ("Third
Amendment") dated as of February 3, 1998, as further amended by that certain Fourth Amendment to Lease
("Fourth Amendment") dated as of February 27, 1998, as further Amended by that certain Fifth Amendment to
Lease ("Fifth Amendment") dated as of March 13, 1998 and as affected by that certain Consent to Assignment
of Lease ("Consent") dated April 2001 (the Lease as so amended and affected by the First Amendment, the
Second Amendment, the Third Amendment, the Fourth Amendment, the Fifth Amendment and the Consent is
hereinafter called the "Prime Lease") which relates to space in the Building (as said term is defined in the Prime
Lease) comprised of approximately 41,020 rentable square feet located on the 1st, 2nd and 3rd floors of the
Building (the "Leased Premises");
WHEREAS, Sublessee desires, and Sublessor has agreed, to sublet a portion of the Leased P