VICAL and CORIXA to Collaborate on Cancer Gene Therapy

i viCAL News Release
9373 TOWNE CE(NTRE I)RIVE, SUITIE 100, SAN I)IEGO, CA 92121 PHONE: (619) i3-99() FAX: (619).-3-88S
FOR IMMEDIATE RELEASE
May 15, 1996
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Contacts: Martha J. Demski Robert H. Zaugg, Ph.D.
Vice President and CFO Vice President, Business Development -
Vical Incorporated Vical Incorporated ___
619-453-9900 619-453-9900 _
VICAL AND CORIXA TO COLLABORATE ON CANCER GENE THERAPY
SAN DIEGO, CA - Vical Incorporated (Nasdaq:VICL) announced today that it will
collaborate with Corixa Corporation of Seattle, WA, to develop immunotherapeutic product
candidates for the treatment of certain cancers utilizing proprietary technology from each company.
The agreement provides Vical with an option to develop therapeutic product candidates for cancer
using Vical's gene-based technology in conjunction with a gene encoding Corixa's proprietary
immunomodulatory protein, called LeIF. LeIF is a parasite-derived protein discovered by Corixa
which is believed to augment immune responses by stimulating in vivo production of several key
effector molecules critical for generation of immunity. Specific terms were not disclosed but include
the payment to Corixa by Vical of an option fee and a potential license fee, milestone payments and
royalties on product sales.
"We're excited about collaborating with the Immunology group at Corixa," said Alain B.
Schreiber, M.D., Vical's President and CEO. "It allows us to gain access to a unique, gene sequence
which, when combined with our gene transfer technology, may result in an appealing new approach
to cancer therapy."
Vical's gene delivery technology is being developed for the administration of synthetic,
"naked DNA" gene constructs directly into tissues in order to trigger the tissue to make the
corresponding proteins. Vical scientists have shown in preclinical models that administration of
single, low doses of naked DNA encoding proteins, such as hormones, results in systemic effects
attributable to that protein.
This press release contains, in addition to historical information, forward-looking statements
that involve risks and uncertainties, including whether any license agreement will be entered into,
whether further development of product candidate will be undertaken, whether any product
candidate can be successfully developed and other risks inherent to the Company's business which
are discussed in the Company's 10-K for the year ended December 31, 1995. Actual results may
differ materially from those projected. These forward-looking statements represent Vical's
judgment as of the date of this release. Vical disclaims, however, any intent or obligation to update
these forward-looking statements.
Corixa Corporation is a privately-held, Seattle-based biotechnology company focused on
discovery and development of new vaccines for use in oncology and infectious disease settings.
Vical Incorporated is focused on the development of gene-based pharmaceutical product

candidates for human therapy. Vical's gene-based therapeutic approach may offer safer and more
cost-effective alternatives for many diseases, including cancer, infectious diseases and autoimmune
disorders.