Five Prime Therapeutics, Inc. (FivePrime), a leader in the discovery and development of innovative biologics, announced that it has formed a focused strategic drug discovery alliance with GlaxoSmithKline (GSK). This new collaboration gives GSK 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 will receive access to FivePrime's comprehensive proprietary collection of secreted proteins and transmembrane receptor proteins. FivePrime will conduct high-throughput in vitro and in vivo assays customized to identify potential drug targets and drug candidates for treating skeletal muscle diseases. GSK will have an option to exclusively license each drug target or drug candidate discovered by FivePrime from the collaboration and take on sole responsibility for additional preclinical studies, clinical development, manufacturing and worldwide commercialization.

FivePrime will receive approximately $15 million in 2010 from an upfront fee, the purchase of FivePrime equity by GSK, and payments related to the research program. In addition, FivePrime is eligible for additional research program payments in 2011 to 2013, and up to $124 million in potential option exercise fees and milestone payments, as well as tiered royalties on global net sales for each product resulting from a selected drug target or drug candidate.

"We are delighted to form this strategic alliance with GSK and harness the power of our unique extracellular proteome library and drug discovery technologies to find new drugs and drug targets for disorders of skeletal muscle," said Lewis T. "Rusty" Williams, MD, PhD, executive chairman and founder of FivePrime.

"Collaborating with GSK will direct additional resources toward accelerating the development of novel drugs for patients suffering from sarcopenia, cachexia, and other skeletal muscle disorders that are not well served today," added Julia P. Gregory, president and chief executive officer.

Sarcopenia is the loss of skeletal muscle mass that accompanies normal aging and accelerates later in life. Sarcopenia is characterized by a decrease in the size of the muscle, which leads to a loss of muscle strength and frailty. Approximately 7% of men and 10% of women ages 60 or older have class II (severe) sarcopenia1. Muscle cachexia is muscle atrophy that accompanies several chronic illnesses including cancer, AIDS, chronic obstructive lung disease, congestive heart failure, and renal failure. There is a high prevalence of cachexia in patients with chronic disease. Although precise numbers of patients with the cachexia syndrome are difficult to quantify, it is estimated that up to 2% of the population suffers from precachexia, characterized by weight loss in association with a chronic disease.

Five Prime Therapeutics, Inc. is a clinical-stage, privately-held company discovering and developing innovative protein and antibody therapeutics. FivePrime is currently testing FP-1039, a first-in-class biologic, in a phase I study for patients with solid tumours.