Xencor Announces Closing of Research Collaboration and License Agreement with Genentech

MONROVIA, Calif.–(BUSINESS WIRE)–Xencor, Inc. (NASDAQ:XNCR), a clinical-stage biopharmaceutical company
developing engineered monoclonal antibodies for the treatment of
autoimmune disease, asthma and allergic diseases, and cancer, today
announced the closing of its research collaboration and license
agreement with Genentech, a member of the Roche Group, following the
expiration of the waiting period under the Hart-Scott Rodino Antitrust
Improvements Act of 1976. Xencor and Genentech entered the agreement to
develop and commercialize novel IL-15 cytokine therapeutics, including
XmAb®24306, an IL-15/IL-15Rα cytokine complex engineered with
Xencor’s bispecific Fc domain and Xtend™ Fc technology.

The agreement is effective as of March 8, 2019, and the related $120
million upfront payment by Genentech to Xencor is due within 30 days of
the effective date. Additional details about the collaboration can be
found in Xencor’s Form 8-K filed with the Securities and Exchange
Commission on February 5, 2019.

About Xencor, Inc.

Xencor is a clinical-stage biopharmaceutical company developing
engineered monoclonal antibodies for the treatment of autoimmune
diseases, asthma and allergic diseases and cancer. Currently, 12
candidates engineered with Xencor’s XmAb® technology are in
clinical development internally and with partners. Xencor’s XmAb
antibody engineering technology enables small changes to the structure
of monoclonal antibodies resulting in new mechanisms of therapeutic
action. For more information, please visit www.xencor.com.

Forward Looking Statements

Statements contained in this press release regarding matters that are
not historical facts are forward-looking statements within the meaning
of applicable securities laws, including, but not limited to, the
quotations from Xencor’s president and chief executive officer and any
expectations relating to Xencor’s financial expectations and business,
the timing and success of clinical trials, future product candidates,
Xencor’s research and development programs, partnering efforts and
capital requirements. Such statements involve known and unknown risks,
uncertainties and other factors that may cause actual results,
performance or achievements and the timing of events to be materially
different from those implied by such statements, and therefore these
statements should not be read as guarantees of future performance or
results. Such risks include, without limitation, the risks associated
with the process of discovering, developing, manufacturing and
commercializing drugs that are safe and effective for use as human
therapeutics and other risks described in Xencor’s public securities
filings. For a discussion of these and other factors, please refer to
Xencor’s annual report on Form 10-K for the year ended December 31, 2018
as well as Xencor’s subsequent filings with the Securities and Exchange
Commission. All forward-looking statements are based on Xencor’s current
information and belief as well as assumptions made by Xencor. You are
cautioned not to place undue reliance on these forward-looking
statements, which speak only as of the date hereof. This caution is made
under the safe harbor provisions of the Private Securities Litigation
Reform Act of 1995. All forward-looking statements are qualified in
their entirety by this cautionary statement and Xencor undertakes no
obligation to revise or update this press release to reflect events or
circumstances after the date hereof, except as required by law.

Contacts

Investor Contact: Charles Liles, Tel: 626-737-8118, cliles@xencor.com;
Corporate Communications Contact: Jason I. Spark, Canale Communications
for Xencor, Tel: 619-849-6005, jason@canalecomm.com