Is a new FDA warning on prostate and hair loss drugs from Merck ($MRK) and GlaxoSmithKline ($GSK) warranted? The agency has announced that the drugs' labeling will include new cautionary language highlighting data suggesting a link to high-risk prostate tumors. The data comes from two new studies that showed the drugs cut the overall risk of prostate cancer but boosted the chance of developing high-grade tumors, the Washington Post reports.
Merck makes Proscar, used to treat enlarged prostate, and Propecia, a hair-loss remedy. GSK's drugs Avodart and Jalyn are also used for enlarged prostate. The two companies had asked the FDA to approve the use of Proscar and Avodart to prevent prostate cancer, based on the data from those two new studies. The agency's expert advisory committee recommended against the new indication. GSK dropped its app soon after.
Those new studies are now coming back to haunt both companies in the form of the new warning. But as Forbes reports, not everyone agrees that the drugs actually do boost the risk of high-grade cancers. One American Cancer Society expert told the magazine that many oncologists believe the drugs don't cause the cancers, but, by shrinking the prostate, make those cancers easier to detect.
"There are a small number of people who think these drugs might cause high grade cancer," the society's CMO, Otis Brawley, said. "I seriously do not see evidence for that." Merck says it stands behind the safety and effectiveness of its drugs, and it noted that Propecia was not actually part of the cancer-prevention trial of Proscar.