FDA panel votes against approving Proscar, Avodart

FDA voted today against approving 2 drugs for the prevention of prostate cancer: finasteride (Proscar, Merck) and dutasteride (Avodart, GlaxoSmithKline).

Both drugs are already approved to treat symptomatic benign prostatic hyperplasia (BPH) in men with an enlarged prostate.

Formulary Editorial Advisor Craig I. Coleman from the University of Connecticut School of Pharmacy, Storrs, CT, said: “Dutasteride and finasteride appear to primarily reduce the risk of lower grade prostate cancers. Take this fact and add in data suggesting these drugs may increase patients’ risk of developing more aggressive prostate cancer, and it is no longer surprising that FDA did not approve the new chemoprevention indication.”

Research presented to the panel by Merck and GlaxoSmithKline showed a 25% decrease in the incidence of low-grade prostate tumors among users of the drugs, according to the Associated Press.

However, concern that a small number of men taking the drugs actually developed more aggressive tumors led the panelists to find that the risk of aggressive tumors outweighed the benefit of reducing tumors that are seldom fatal, the Associated Press reported.

FDA reportedly had concerns about using the medications for the prevention of prostate cancer, including the fact that black men, who are at high risk for the disease, were underrepresented in the clinical trials. Blacks made up 4% of patients in the Merck Study and 2% of patients in the GlaxoSmithKline study.

The panel of outside experts assembled by FDA also discussed the overall value of preventing low-grade tumors. According to FDA, more than three-quarters of the tumors the drugs prevent are slow-growing, meaning they are non-aggressive and probably not life-threatening for anyone with a life expectancy of

Also, slightly more aggressive tumors were seen in men taking finasteride and dutasteride, compared with those taking placebo, according to FDA. But the pharamaceutical companies say the drugs simply make those tumors easier to detect because they shrink the prostate.

“While we are disappointed by the Committee’s conclusions on dutasteride as a prostate-cancer risk-reduction therapy, it is important to note that dutasteride has an established efficacy and safety profile in the treatment of BPH, including trials involving 10,000 men and the cumulative of 5.5 million years of patient exposure,” said Anne Phillips, MD, vice president, medicine development leader, Oncology Research and Development, GlaxoSmithKline. “We will continue to work with the FDA on the review of thesNDA.”