Press Release

Our enduring purpose: To fundamentally improve the lives of patients with serious diseases in ways never before possible

Five Prime to Present at 2018 ASCO Annual Meeting

April 25, 2018 at 3:01 PM EDT

SOUTH SAN FRANCISCO, Calif.--(BUSINESS WIRE)--Apr. 25, 2018-- Five Prime Therapeutics, Inc. (Nasdaq:FPRX), a clinical-stage biotechnology company focused on discovering and developing innovative immuno-oncology protein therapeutics, today announced that it will present two posters during the 2018 American Society of Clinical Oncology (ASCO) Annual Meeting, being held June 1-5, 2018, in Chicago.

Abstract Number and Title: #TPS4135, “FIGHT: A Phase 3 Randomized, Double-Blind, Placebo Controlled Study Evaluating (Bemarituzumab) FPA144 and Modified FOLFOX6 (mFOLFOX6) in Patients with Previously Untreated Advanced Gastric and Gastroesophageal Cancer with a Dose Finding Phase 1 Lead-In”
Poster Session: Gastrointestinal (Noncolorectal) Cancer
Session Date and Time:Sunday, June 3, 2018; 8:00 – 11:30 a.m. CT
Location: Hall A,PosterBoard Number: #322a

Abstract Number and Title: #3020, “Pharmacodynamics (PD) and Genomic Profiling of Pts Treated with cabiralizumab (cabira) + nivolumab (NIVO) Provide Evidence of On-Target Tumor Immune Modulations and Support Future Clinical Applications”
Poster Session: Developmental Therapeutics - Immunotherapy
Session Date and Time:Monday, June 4, 2018; 8:00 – 11:30 a.m. CT
Location: Hall A, Poster Board Number: #234
Discussion Session Date and Time:Monday, June 4, 2018; 11:30 a.m.12:45 p.m. CT
Discussion Session Location: Hall B1

About Bemarituzumab (FPA144)

Bemarituzumab is an isoform-selective, humanized monoclonal antibody in clinical development as a targeted immuno-therapy for tumors that overexpress FGFR2b, a splice variant of a receptor for some members of the fibroblast growth factor (FGF) family. Clinical results to date suggest that the specificity of FPA144 avoids toxicities that have been seen with less selective FGFR2 small molecule therapeutics. FPA144 has also been engineered for enhanced antibody-dependent cell-mediated cytotoxicity (ADCC) to increase direct tumor cell killing by recruiting natural killer (NK) cells.

About Cabiralizumab (FPA008)

Cabiralizumab is an investigational antibody that inhibits the CSF-1 receptor and has been shown in preclinical models to block the activation and survival of monocytes and macrophages. Inhibition of CSF1R in preclinical models of several cancers reduces the number of immunosuppressive tumor-associated macrophages (TAMs) in the tumor microenvironment, thereby facilitating an immune response against tumors. Cabiralizumab is currently in clinical trials in oncology indications and in pigmented villonodular synovitis (PVNS). Cabiralizumab is being developed under an exclusive worldwide license and collaboration agreement entered into with Bristol-Myers Squibb (BMS) in October 2015.

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 the 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 or follow us on LinkedIn, Twitter and Facebook.

Cautionary Note on Forward-looking Statements

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Words such as "may," "will," "expect," "plan," "anticipate," "estimate," "intend" and similar expressions (as well as other words or expressions referencing future events, conditions or circumstances) are intended to identify forward-looking statements. These forward-looking statements are based on Five Prime's expectations and assumptions as of the date of this press release. Each of these forward-looking statements involves risks and uncertainties. Actual results may differ materially from these forward-looking statements. Forward-looking statements contained in this press release include statements about Five Prime's potential receipt of milestone payments and royalties. Many factors may cause differences between current expectations and actual results, including unexpected safety or efficacy data observed during non-clinical or clinical studies, clinical site activation rates or clinical trial enrollment rates that are lower than expected and changes in expected or existing competition. Other factors that may cause actual results to differ from those expressed or implied in the forward-looking statements in this press release are discussed in Five Prime's filings with the U.S. Securities and Exchange Commission, including the "Risk Factors" contained therein. Except as required by law, Five Prime assumes no obligation to update any forward-looking statements contained herein to reflect any change in expectations, even as new information becomes available.

Source: Five Prime Therapeutics, Inc.

Five Prime Therapeutics, Inc.
Heather Rowe, 415-365-5737
Senior Director, Investor Relations and Corporate Communications