|XGEVA 12-1 vote against expanding use. Seems neutral with respect to cabo... ???|
A federal advisory panel rejected a proposal Wednesday by Amgen Inc. to expand the use of its bone drug Xgeva in men with prostate cancer that has not spread to the bones.
Xgeva is currently approved to delay fractures and other bone injuries in patients whose cancer has already spread to the bones.
The company is seeking approval from the Food and Drug Administration for the use of Xgeva to prevent the spread of prostate cancer that has not responded to other therapies, or essentially to give the drug at an earlier time point in the disease.
Xgeva was reviewed Wednesday by the FDA's oncologic drugs advisory committee which is made up of non-FDA medical experts.
The panel voted negatively 12 to 1 on whether Xgeva "demonstrated a favorable risk/benefit evaluation" in men with prostate cancer who are at high risk of having the cancer spread to the bones. The vote amounts to a recommendation that FDA not approve Xgeva for that use. The FDA isn't required to follow the recommendation but usually follows the advice of its advisory panels.
"This isn't a question of whether this drug works," said Wyndam Wilson, the panel's chairman and the chief of the lymphoma therapeutics division at the National Cancer Institute. "The question is when is the most effective time to give it."
Amgen conducted a study of Xgeva in 1,432 men with prostate cancer that hadn't responded to previous therapies, but had not spread to the bones. Many types of cancer spread to the bones and cause tumors to grow, destroying the bone around the tumor, and causing fractures and other problems.
Half of the men were treated with Xgeva while the other half received a placebo. The study examined the time until men developed bone metastases or died, whichever occurred first. The study showed Xgeva prolonged median bone metastatis-free survival by 4.2 months compared to patients in the placebo group.
While the FDA said the study met its primary objective, the agency said it was unclear whether the results were "clinically meaningful" given that there was no difference in overall survival between the two patient groups.
The agency said the risk-benefit ratio of Xgeva must also take into account the overall toxicity of the drug. One of the side effects includes a risk of developing osteonecrosis of the jaw, or ONJ, a rare jaw-decay problem, which was seen in about 5% of patients taking Xgeva in the clinical study.
Michael Severino, Amgen's vice president of research and development, said in an interview on Monday that the company believes Xgeva does provide a clinically meaningful benefit because it delays the spread of cancer to the bone, which causes significant pain and other problems such as incontinence.
Xgeva is also sold under the brand name Prolia as an osteoporosis treatment but is administered at a lower dose and less often than used to treat cancer-related bone complications. Xgeva's and Prolia's combined sales in 2011 topped $550 million. The drugs target a protein called RANK Ligand, which helps regulate cells called osteoclasts that break down bone.