Five Prime Announces Cabiralizumab Phase 1a/1b Data Abstract Selected for Late Breaking Oral Presentation at the Society for Immunotherapy of Cancer (SITC) 32nd Annual Meeting

SOUTH SAN FRANCISCO, Calif., Oct. 11, 2017 -- Five Prime Therapeutics, Inc. (Nasdaq:FPRX), a clinical-stage biotechnology company focused on discovering and developing innovative immuno-oncology protein therapeutics, today announced that the abstract featuring data from the Phase 1a/1b clinical trial evaluating the immunotherapy combination of its CSF-1R antibody, cabiralizumab (FPA008), with Opdivo® (nivolumab), Bristol-Myers Squibb's PD-1 immune checkpoint inhibitor, has been selected for a late breaking oral presentation at the Society for Immunotherapy of Cancer (SITC) 32^nd Annual Meeting, being held Nov. 8-12, 2017 in National Harbor, Maryland.

Society for Immunotherapy of Cancer (SITC) Presentation
Session Name: Clinical Trials and Novel Combinations
Abstract Title: “First in Human Phase I Dose Escalation and Expansion of a novel combination, anti-CSF1-receptor (cabiralizumab) plus anti-PD-1 (nivolumab) in patients with advanced solid tumors.”
Session Date and Time: Saturday, Nov. 11, 2017, 3:30-6:00 PM EST
Presentation Time: 4:30-4:45 PM EST

This will be the first presentation of clinical data on a combination of a CSF-1R antibody and a checkpoint inhibitor, to the Company’s knowledge.

In the Phase 1a/1b trial, Five Prime and Bristol-Myers Squibb are evaluating the safety, tolerability and preliminary efficacy of the combination in advanced solid tumors.  The presentation at the SITC Annual Meeting will focus on preliminary safety, pharmacokinetic and pharmacodynamic data as well as initial efficacy data from one of the expansion cohorts.

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.

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. 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.

CONTACT:
Derek Cole
Investor Relations Advisory Solutions
720-785-4497
[email protected]