THOUSAND OAKS, Calif., April 26, 2012 /PRNewswire/ -- Amgen (NASDAQ: AMGN) today announced that the U.S. Food and Drug Administration (FDA) has issued a Complete Response Letter for the supplemental Biologics License Application (sBLA) for XGEVA® (denosumab) to treat men with castration-resistant prostate cancer (CRPC) at high risk of developing bone metastases. The Complete Response Letter states that FDA cannot approve the application in its present form. The FDA determined that the effect on bone metastases-free survival (BMFS) was of insufficient magnitude to outweigh the risks (including osteonecrosis of the jaw) of XGEVA in the intended population, and requested data from an adequate and well-controlled trial(s) demonstrating a favorable risk-benefit profile for XGEVA that is generalizable to the U.S. population. "We are reviewing the complete response letter and will work with FDA to determine any next steps," said Sean E. Harper, M.D., executive vice president of Research and Development at Amgen. "The FDA's action today does not impact the approved indication of XGEVA in the prevention of skeletal-related events in men with bone metastases from prostate cancer, which was acknowledged by the FDA and the advisory committee members who discussed the application." About XGEVAXGEVA is the first-and-only RANK Ligand inhibitor approved by the FDA for the prevention of skeletal-related events (SREs) in patients with bone metastases from solid tumors, including prostate cancer. XGEVA was initially approved following a six month priority review by the FDA. XGEVA is not indicated for the prevention of SREs in patients with multiple myeloma. XGEVA is the first novel bone metastases treatment for advanced cancer patients in nearly a decade. Delivered as an every four week 120 mg subcutaneous injection, XGEVA provides a unique option for urologists and oncologists to prevent SREs in patients with bone metastases from solid tumors. XGEVA is a fully human monoclonal antibody that binds to RANK Ligand, a protein essential for the formation, function and survival of osteoclasts (the cells that break down bone). XGEVA prevents RANK Ligand from activating its receptor, RANK, on the surface of osteoclasts, thereby decreasing bone destruction.