US FDA panel negative on extending GSK's Avodart and Merck & Co's Proscar use; Agency delays ezogabine

In what may well have been expected given somewhat negative briefing papers from US Food and Drug Administration staff ahead of an advisory panel meeting yesterday, the verdict was that the benefits of GlaxoSmithKline's (LSE: GSK) Avodart (dutasteride) and Merck & Co's (NYSE: MRK) Proscar (finasteride) fail to outweigh their risks in preventing prostate cancer in certain men (The Pharma Letter November 30).

Both Avodart and Proscar are already approved for the treatment of enlarged prostate, and studies by both companies showed their drugs decreased incidence of low-grade prostate tumors by nearly 25%. However, reports ABC News, panelists voiced concern that a small number of men taking the drugs actually developed more aggressive tumors, compared with those given a placebo. Panelists said the risk of increasing fatal tumors outweighed the benefit of reducing tumors that are seldom fatal.

"In a setting like this, the onus is on the drug to be completely safe, and to show benefit, and I don't think it reached that level," said FDA Oncologic Drugs Advisory Committee chairman Wyndham Wilson, of the National Cancer Institute.