(Adds comment from panelist, background)
WASHINGTON, May 24 (Reuters) - Puma Biotechnology Inc's experimental breast cancer drug reduces the risk of disease recurrence and should be approved, an advisory committee to the U.S. Food and Drug Administration concluded on Wednesday.
The panel voted 12 to 4 in favor of the drug, neratinib, saying its benefits outweighed the risks, though panelists noted that the magnitude of the benefit was modest. The FDA is not obliged to follow the recommendations of its advisory panels, but typically does so.
The difference in the rate of disease-free survival between patients taking neratinib and those taking a placebo after two years was 2.3 percent, meaning that out of 100 women, cancer returned in 5.8 women in the neratinib group compared with 8.1 in the placebo group.
"The benefit in absolute terms is relatively modest," said Dr. Grzegorz Nowakowski, associate professor of medicine and oncology at the Mayo Clinic in Rochester, adding: "toxicity appears to be manageable."
The most significant side effect of the drug was diarrhea, which affected 95 percent of patients. In 40 percent of cases, the diarrhea was severe. In total, 28 percent of patients discontinued neratinib due to a side effect.
The drug is designed to treat early stage breast cancer in patients with the HER2 genetic mutation whose tumor has been surgically removed and who have been treated with Roche Holding AG's Herceptin, a drug which itself reduces the risk of the disease returning. (Reporting by Toni Clarke in Washington, editing by G Crosse)