Five Prime Presents First Preclinical Data on Anti-CCR8 Antibody FPA157

Five Prime Therapeutics, Inc. (NASDAQ: FPRX) today presented the first preclinical data from its anti-CCR8 FPA157 program at The Society for Immunotherapy of Cancer (SITC) 35th Anniversary Annual Meeting & Pre-Conference Programs (SITC 2020).

The poster, “Development of FPA157, an anti-CCR8 depleting antibody engineered to preferentially eliminate tumor-infiltrating T regulatory cells,” was presented in a late-breaker live Q&A session and is available here.

Key highlights from the poster included:

• CCR8 expression is highly restricted to T regulatory (Treg) cells within the tumor
• Preclinical efficacy studies demonstrate that anti-CCR8 antibody treatment depletes CCR8+ Tregs in the tumor microenvironment while sparing peripheral Treg subsets
• Anti-CCR8 treatment elicits the development of robust anti-tumor memory responses
• FPA157 leads to potent natural killer (NK) cell-dependent killing of CCR8+ target cells

“Preclinical data for FPA157 suggest that selective depletion of regulatory T cells within the tumor— without affecting peripheral Tregs—is a promising and exciting therapeutic pathway to pursue,” said Andrew Rankin, PhD, Vice President of Research. “This is the first time we are publicly sharing information about the CCR8 inhibitor antibody in the Five Prime immuno-oncology pipeline and to do so at SITC is very rewarding. We are eager to further investigate the potential of FPA157 in the clinic.”

There will be two live Q&A sessions with poster author Edwina Naik, PhD, Associate Director, Immuno-Oncology Research. The first is today, November 11, 2020 from 5:15-5:45pm EST and the second is on November 13, 2020 from 4:40-5:10pm EST.

About FPA157

FPA157 is a monoclonal antibody targeting CCR8 that is designed to enhance antibody-dependent cell-mediated cytotoxicity (ADCC) and deplete the T regulatory cell (Treg) population in the tumor microenvironment. Tregs inhibit anti-tumoral immune responses and act through multiple suppressive mechanisms.^1,2 FPA157 is part of the Five Prime immuno-oncology antibody pipeline and is undergoing IND-enabling studies.

About Five Prime Therapeutics

Five Prime Therapeutics, Inc. discovers and develops innovative protein therapeutics to improve the lives of patients with serious diseases. Five Prime’s product candidates have innovative mechanisms of action and address patient populations in need of better therapies. The company focuses on researching and developing immuno-oncology and targeted cancer therapies paired with companion diagnostics to identify patients who are most likely to benefit from treatment with Five Prime’s product candidates. Five Prime has entered into strategic collaborations with leading global pharmaceutical companies and has promising product candidates in clinical and preclinical development. For more information, please visit www.fiveprime.com.