Five Prime Presents Preclinical Research Data on Novel B7-H4 Therapeutic Antibody at ESMO 2017 Congress

SOUTH SAN FRANCISCO, Calif., Sept. 10, 2017 -- Five Prime Therapeutics, Inc. (Nasdaq:FPRX), a clinical-stage biotechnology company focused on discovering and developing innovative immuno-oncology protein therapeutics, announced that an oral poster discussion featuring data related to FPA150, Five Prime’s novel B7-H4 antibody, was presented today at the European Society for Medical Oncology (ESMO) 2017 Congress in Madrid, Spain. The poster titled “FPA150, a Novel B7-H4 Therapeutic Antibody with Checkpoint Blockade and ADCC Activities” by Charles Kaplan et al. is available at http://www.fiveprime.com/news-media/publications-presentations.

“B7-H4 represents an ideal target for a therapeutic antibody,” said Bryan Irving, Ph.D., Senior Vice President of Research at Five Prime. “B7-H4 is expressed in several solid tumor types not typically associated with PD-L1 expression and its expression negatively correlates with patient outcome. Moreover, B7-H4 represents a T cell checkpoint ligand that is not currently targeted by other immuno-oncology agents. As such, we feel that our monoclonal B7-H4 antibody, FPA150, which appears to possess both T cell checkpoint blockade activity and enhanced ADCC, has the potential to be an effective therapeutic by improving anti-tumor immune responses in cancer patients who may not respond well to PD-1 or PD-L1-targeted agents.”

B7-H4 shares significant homology with other B7 family members, including PD-L1 and PD-L2. B7-H4 is expressed in several human tumors such as carcinomas of the breast, ovary and endometrium, and its expression tends to correlate with poor prognosis. While the receptor for B7-H4 is unknown, it is believed to be expressed on T cells because B7-H4 is described as a ligand capable of directly inhibiting T cell activity.

FPA150 is a high affinity, afucosylated B7-H4 monoclonal antibody that has demonstrated potent antibody-dependent cell-mediated cytotoxicity (ADCC) and T cell checkpoint blockade activity in vitro and significant dose-dependent anti-tumor efficacy in vivo.

Five Prime is currently developing FPA150 and IND-enabling studies are ongoing.

About Five Prime

Five Prime Therapeutics, Inc. discovers and develops innovative therapeutics to improve the lives of patients with serious diseases. Five Prime's comprehensive discovery platform, which encompasses virtually every medically relevant extracellular protein, positions it to explore pathways in cancer, inflammation and their intersection in immuno-oncology, an area with significant therapeutic potential and a growing focus of the company's R&D activities. Five Prime has entered into strategic collaborations with leading global pharmaceutical companies and has promising product candidates in clinical and late preclinical development. For more information, please visit www.fiveprime.com.

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CONTACT:
Derek Cole
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