Five Prime Therapeutics, Inc. is a clinical-stage biotechnology company, which focuses on discovering and developing novel protein therapeutics. The company advanced product candidates includes, FPA008, FPA144 and FP-1039/GSK3052230. The FPA008 is an antibody that inhibits colony stimulating factor-1, or CSF1, receptor, or CSF1R, that are developing in rheumatoid arthritis and plan to clinically develop in pigmented villonodular synovitis, or PVNS, and in combination with nivolumab in multiple cancers. The FPA144 is an antibody that inhibits fibroblast growth factor receptor 2b, or FGFR2b, that are developing to treat patients with gastric (stomach) cancer. The FP-1039/GSK3052230 is a fusion protein that traps and neutralizes cancer-promoting fibroblast growth factors. Five Prime Therapeutics was founded by Lewis T. Williams in December 2001 and is headquartered in South San Francisco, CA.