Human Genome Sciences (HGS) is paying FivePrime Therapeutics $50 million up front and potentially another $445 million in development, regulatory, and commercial milestones for rights to the latter’s Phase I-stage anticancer candidate, FP-1039, in the U.S., Canada, and EU. Under terms of the deal, HGS has rights to develop and commercialize the candidate for all indications in its designated territories. FivePrime retains all rights to the fibroblast growth factor inhibitor and any follow-on products in the rest of the world. The firm in addition retains minority co-promotion rights to FP-1039 in the U.S. It will earn tiered, double-digit royalty payments on net sales by HGS.
FP-1039 is a soluble fusion protein comprising the extracellular portion of fibroblast growth factor receptor 1 (FGFR1) attached to the base of a human antibody. The candidate acts as a ligand trap that inhibits most members of the FGF family, FivePrime explains. FP-1039 is expected to exert a dual effect on cancer cells that inhibits tumor cell growth directly and blocks tumor-associated angiogenesis. Phase I dose-escalation trials in patients with advanced solid tumors are ongoing, and patients are currently being screened for a Phase II study in a form of endometrial cancer, FivePrime notes.
FP-1039 addresses a signaling pathway that has historically remained untapped for drug development, and the collaboration with HGS will maximize the potential for developing the drug, the firm claims. “It will significantly broaden the clinical plan for FP-1039, enabling us to address the multiple tumor types in which FP-1039 may have activity,” remarks Julia P. Gregory, FivePrime’s president and CEO.
FivePrime has generated what it claims is the most comprehensive collection of human secreted proteins and extracellular receptors, which is being screened in medically relevant cell-based and in vivo screens to look for drug development candidates in the fields of oncology, immunology, and metabolic diseases.
FP-1039 is the firm’s lead candidate and the first to enter clinical development. Phase I studies with an IL-34 ligand trap, FP-1069, are planned to start later this year. FivePrime claims it discovered IL-34 using its screen for monocyte survival factors. FP-1069 is in development as a potential treatment for autoimmune diseases including multiple sclerosis and rheumatoid arthritis. The firm is collaborating on the development of FP-1069 with Fast Forward, a subsidiary of the National Multiple Sclerosis Society. Lead preclinical-stage molecule for metabolic disease, FPT038, is a potential protein therapeutic for diabetes that increases glucose uptake into muscle without causing the hypoglycemic side effects associated with insulin therapy.
FivePrime is in addition exploiting its technologies through collaborations with the industry. In August 2010 the firm signed a drug discovery alliance with GlaxoSmithKline (GSK) giving the U.K. drug giant exclusive access to FivePrime’s drug discovery platforms specifically in the areas of sarcopenia, cachexia, and other skeletal muscle disorders. Under the terms of the agreement, GSK has access to FivePrime’s collection of secreted proteins and transmembrane receptor proteins. The latter will conduct high-throughput in vitro and in vivo assays customized to identify potential drug targets and drug candidates for treating skeletal muscle diseases.