Five Prime Therapeutics, Inc., a clinical-stage biotechnology company, focuses on the discovery and development of immuno-oncology protein therapeutics in the United States. The company's product candidates include Cabiralizumab, an antibody that inhibits colony stimulating factor-1 receptor and is in Phase Ia/Ib clinical trials for the treatment of various cancers in combination with nivolumab; and is in Phase I/II clinical trials for the treatment of pigmented villonodular synovitis tumor, as well as conducts Phase I clinical trials for the treatment of rheumatoid arthritis. Its product candidates also comprise FPA144, an antibody that inhibits fibroblast growth factor receptor IIb and is in Phase I clinical trials to treat patients with gastric cancer; and FP-1039, a fusion protein that traps and neutralizes cancer-promoting fibroblast growth factors. The company's FP-1039 is in Phase Ib clinical trials to treat patients with malignant pleural mesothelioma. Its preclinical product candidates include FPA150, a CD8 T cell checkpoint inhibitor antibody; FPA154, a tetravalent agonistic antibody that activates glucocorticoid-induced tumor necrosis factor receptor; and FPT155, a CD80-Fc fusion protein, which modulates signaling pathways. The company has license and collaboration agreement with GlaxoSmithKline LLC, Bristol-Myers Squibb Company, and UCB Pharma S.A.; and license agreement with INBRX 110 LP, Galaxy Biotech, LLC, BioWa, Inc., and Lonza Sales AG. Five Prime Therapeutics, Inc. was founded in 2001 and is headquartered in South San Francisco, California.