FDA doubts benefits of Amgen drug for prostate cancer

Amgen says that its bone drug can also help people suffering from prostate cancer. But the Food and Drug Administration is questioning whether the drug provides "an adequate measure of clinical benefit" for patients with prostate cancer, Reuters reported. The FDA's oncologic drugs advisory committee will review the drug Wednesday. 

The FDA has already approved Amgen's drug Xgeva for preventing fractures in cancerous bones. Xgeva is also marketed under the brand name Prolia for treating osteoporosis.  

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In May, a clinical trial by Amgen showed that Xgeva could also delay metastasis, or the spread of cancer to the bone, in patients with prostate cancer, "which could significantly extend its market potential," Pharma Times reported.

Xgeva did delay metastasis by 4.2 months in a clinical trial. However, patients in the drug group did not live any longer than those in the placebo group, the FDA said. An editorial in the medical journal Lancet also argued that the benefits of the drug do not outweigh its risks. 

Xgeva's side effects include a rare jaw-decay condition called osteonecrosis of the jaw, reported the Wall Street Journal. 

An analyst told the Associated Press that "the FDA is critical of the data" and "questioning the clinical meaningfulness" of using Xgeva to treat prostate cancer. The FDA isn't expected to make a final decision on the drug's approval until April.

Xgeva and Prolia had sales of $554 million in 2011, the AP reported, but shares recently fell 2.6 percent.