NEWS & INSIGHTS

SEATTLE, Washington – July 7, 2021 – OncoResponse, a biotechnology company harnessing the
power of the human immune system to identify and develop novel monoclonal antibodies to
immunosuppressive myeloid targets for cancer immunotherapy, today announced the
appointment of Sean A. McCarthy, D. Phil., as an Independent Director to its Board of Directors.
Dr. McCarthy brings over 20 years of experience in the biotechnology industry having served in
roles in R&D, business development, finance and general management and currently serves as
President, Chief Executive Officer and Chairman of CytomX.

“Sean is a highly accomplished executive in our industry and has a wonderful breadth of
perspective and experience,” said Clifford Stocks, Chief Executive Officer of OncoResponse. “As
a skilled scientific and business leader, Sean deftly guided CytomX from development-stage to
publicly-held company and is directly familiar with the growth opportunity ahead for
OncoResponse. His advice and counsel will be valuable as we harness our drug discovery and
development efforts to deliver impactful cancer therapies.”

Dr. McCarthy joined CytomX in 2010 as Chief Business Officer and has served as Chief Executive
Officer since 2011. Previously, Dr. McCarthy spent four years as a Transactional Partner at
Pappas Ventures. Prior to Pappas, Sean drove a strategic reorganization of SGX Pharmaceuticals
from a platform model to product-focused oncology company and served in multiple roles at
Millennium Pharmaceuticals. Dr. McCarthy is an author on multiple peer-reviewed scientific
publications and issued patents and remains a member of the Board of Directors and Executive
Committee of the California Life Sciences Association. Dr. McCarthy received his Bachelor of
Science degree in biochemistry and pharmacology at King’s College, University of London. He
also received an MBA from the Rady School of Management at UCSD and a D. Phil. in cancer
biology from St. John’s College, University of Oxford.

“I am delighted to join the Board of OncoResponse and help advance their innovative approach
to leveraging the human immune system to fight cancer,” said Dr. McCarthy. “The Company’s
growing pipeline of antibody therapeutics which target unique aspects of the tumor
microenvironment are moving OncoResponse to the forefront. I look forward to working with
fellow Board members and Company leadership to further strengthen OncoResponse and
transform the treatment of cancer.”

ABOUT ONCORESPONSE
OncoResponse, Inc., an immuno-oncology focused biotech company, in a broad strategic
alliance with MD Anderson Cancer Center, uses a proprietary B-cell technology platform to
mine the immune system of cancer patients who have responded to cancer immunotherapy to
discover novel targets and antibodies, and develop therapeutic monoclonal antibodies to treat
cancer. OncoResponse has several antibodies directed at modulating immunosuppression of
the tumor microenvironment in pre-clinical development and a CD163 targeting antibody
entering clinical studies summer 2021. OncoResponse, Inc. is a privately held company backed
by investment from MD Anderson Cancer Center, Rivervest Venture Partners, Redmile Group,
Magnetar Group, Yonjin Venture, Bering Capital, ARCH Venture Partners, Helsinn Investment
Fund, Canaan Partners, GreatPoint Ventures, Takeda Ventures, Buchang Pharma, Alexandria
Real Estate Equities and William Marsh Rice University. For more information please
visit: www.oncoresponseinc.com

INVESTOR CONTACT:
John Graziano
Solebury Trout
+1 646-378-2942
jgraziano@soleburytrout.com