Bristol-Myers Squibb and CytomX Therapeutics Extend Worldwide Collaboration to Discover Probody™ Therapeutics for the Treatment of Cancer and Other Diseases

NEW YORK & SOUTH SAN FRANCISCO, Calif.–(BUSINESS WIRE)– Bristol-Myers
Squibb Company (NYSE:BMY) and CytomX
Therapeutics, Inc. (Nasdaq:CTMX), a biopharmaceutical company
developing investigational Probody therapeutics for the treatment of
cancer, today announced an expansion of their 2014 strategic
collaboration to discover novel therapies that will include up to eight
additional targets using CytomX’s proprietary Probody platform.

Probody therapeutics are designed to take advantage of unique conditions
in the tumor microenvironment to enhance the tumor-targeting features of
an antibody and reduce drug activity in healthy tissues. By remaining
inactive until they are activated by proteases in the tumor
microenvironment, Probody therapeutics bind selectively to cells within
tumor tissue with reduced binding to healthy tissue, potentially
improving or creating a therapeutic window. Probody therapeutics may
also have application in other diseases where proteases are dysregulated
in affected tissues.

As part of the original collaboration signed in May 2014 to discover,
develop and commercialize Probody therapeutics, Bristol-Myers Squibb
selected four oncology targets, including CTLA-4. In the collaboration
to date, Bristol-Myers Squibb has progressed the CTLA-4 Probody
therapeutic to Investigational New Drug-enabling studies and the three
other programs are in the lead discovery and optimization phase.

“CytomX’s Probody platform has enhanced our discovery research as we
seek to direct the therapeutic effects of immunotherapy in a more
targeted approach against tumors,” said Carl Decicco, Ph.D., Head of
Discovery, Bristol-Myers Squibb. “We look forward to working more
extensively with CytomX on this innovative and potentially disruptive
approach in oncology as well as other disease areas.”

“This expanded collaboration with Bristol-Myers Squibb gives CytomX the
opportunity to further the reach of our potentially transformational
Probody technology and provides us with additional financial and
strategic flexibility to build our company,” said Sean
McCarthy, D. Phil., President and Chief Executive Officer. “With
CX-072 in Phase 1/2, and CX-2009 approaching clinical studies, our broad
wholly-owned pipeline is poised for initial proof of concept as we aim
to reinvent therapeutic antibodies.”

Under the terms of the agreement, CytomX will grant Bristol-Myers Squibb
exclusive worldwide rights to develop and commercialize Probody
therapeutics for up to six additional oncology targets and two
non-oncology targets. Bristol-Myers Squibb will make an upfront payment
of $200 million to CytomX and, in addition, will provide research
funding over the course of the research term. CytomX will also be
eligible to receive up to $448 million in future development, regulatory
and sales milestone payments for each collaboration target, as well as
tiered royalties from the mid-single digits to low-double digits on net
sales of each product commercialized by Bristol-Myers Squibb.

Closing of the transaction is subject to clearance under the
Hart-Scott-Rodino Antitrust Improvements Act.

About Bristol-Myers Squibb

Bristol-Myers Squibb is a global biopharmaceutical company whose mission
is to discover, develop and deliver innovative medicines that help
patients prevail over serious diseases. For more information about
Bristol-Myers Squibb, visit us at BMS.com or
follow us on LinkedIn,
Twitter,
YouTube and
Facebook.

About CytomX Therapeutics

CytomX is a clinical-stage, oncology-focused biopharmaceutical company
pioneering a novel class of investigational antibody therapeutics based
on its Probody technology platform. The company uses its platform to
create proprietary cancer immunotherapies against clinically-validated
targets, such as PD-L1, and develop first-in-class cancer therapeutics
against difficult-to-drug targets, such as CD166. Probody therapeutics
are designed to take advantage of unique conditions in the tumor
microenvironment to enhance the tumor-targeting features of an antibody
and reduce drug activity in healthy tissues. The company’s lead program,
CX-072, a wholly-owned PD-L1-targeting Probody therapeutic, is being
evaluated in a Phase 1/2 study. CX-072 is part of PROCLAIM (Probody
Clinical Assessment In Man), an international umbrella clinical trial
program that provides clinical trial sites with access to the company’s
novel therapies under one central protocol. The Investigational New Drug
filing for CX-2009, a first-in-class Probody drug conjugate targeting
the highly expressed tumor antigen, CD166, is targeted for the first
half of 2017. In addition to its proprietary programs, CytomX is
collaborating with strategic partners including AbbVie, Bristol-Myers
Squibb Company, Pfizer Inc., MD Anderson Cancer Center and ImmunoGen,
Inc. For more information, visit www.cytomx.com
or follow us on Twitter.

Bristol-Myers Squibb Forward-Looking Statement

This press release contains “forward-looking statements” as that term
is defined in the Private Securities Litigation Reform Act of 1995
regarding the research, development and commercialization of
pharmaceutical products. Such forward-looking statements are based on
current expectations and involve inherent risks and uncertainties,
including factors that could delay, divert or change any of them, and
could cause actual outcomes and results to differ materially from
current expectations. No forward-looking statement can be guaranteed.
Forward-looking statements in this press release should be evaluated
together with the many uncertainties that affect Bristol-Myers Squibb’s
business, particularly those identified in the cautionary factors
discussion in Bristol-Myers Squibb’s Annual Report on Form 10-K for the
year ended December 31, 2016 in our Quarterly Reports on Form 10-Q and
our Current Reports on Form 8-K. Bristol-Myers Squibb undertakes no
obligation to publicly update any forward-looking statement, whether as
a result of new information, future events or otherwise.

CytomX Therapeutics Forward-Looking Statements

This press release includes forward-looking statements. Such
forward-looking statements involve known and unknown risks,
uncertainties and other important factors that are difficult to predict,
may be beyond our control, and may cause the actual results, performance
or achievements to be materially different from any future results,
performance or achievements expressed or implied in such statements.
Accordingly, you should not rely on any of these forward-looking
statements. Our Probody platform is beginning clinical development, and
the process by which clinical development could potentially lead to an
approved product is long and subject to significant risks and
uncertainties. Collaborations with partners may not result in
products, and milestone payments and royalties may not be received.
Projected net cash utilization and capital resources are subject to
substantial risk of variance based on a wide variety of factors that can
be difficult to predict. Applicable risks and uncertainties
include those relating to our preclinical research and development,
clinical development, and other risks identified under the heading « Risk
Factors » included in our filings with the SEC. The forward-looking
statements contained in this press release are based on information
currently available to CytomX and speak only as of the date on which
they are made. CytomX does not undertake and specifically disclaims any
obligation to update any forward-looking statements, whether as a result
of any new information, future events, changed circumstances or
otherwise.

View source version on businesswire.com: http://www.businesswire.com/news/home/20170320005171/en/