According to federal advisors last Thursday, obesity drugs should undergo clinical trials to ensure that they do not cause heart attacks. This would make it harder for these drugs to receive approval.
An advisory committee to the Food and Drug Administration (FDA) voted 17 to 6 to require such studies, even if there were no apparent signs that a drug increased cardiovascular risk. “Given the checkered history of weight-loss drugs, I think it is better to be prudent and err on the side of caution,” Dr. Sanjay Kaul, a cardiologist at Cedars-Sinai Medical Center in Los Angeles, said at the end of the two-day meeting in Silver Spring, Md.
“Anti-obesity drugs have a bad track record of cardiovascular risk,” said Dr. Marvin Konstam, a professor at Tufts University School of Medicine and panel member. The FDA usually follows panel recommendations, although it is not required to, and will make a final decision later.
But some committee members warned that such a requirement would increase the time and cost of developing weight-loss drugs, discouraging pharmaceutical companies. “If the F.D.A. follows through with this vote, you’ve just added another big disincentive for the drug companies to come up with obesity drugs, and we desperately need new drugs,” said Dr. Ed J. Hendricks, an obesity specialist in Sacramento, who voted with the minority. .
The F.D.A. usually follows the advice of its committees but it does not have to. It was not known how this would affect the fates of two obesity drugs awaiting approval from the F.D.A. — Qnexa from Vivus and Lorqess from Arena pharmaceuticals. Two drugs associated with the fen-phen diet pill combination were removed from the market in 1997 because of damage to heart valves. In 2010, the drug Meridia from Abbott Laboratories was withdrawn after a clinical trial showed it increased the risk of cardiovascular problems in patients. Because one-third of American adults are obese and another third are overweight, some obesity specialists and patient advocates say new drugs are needed. Xenical from Roche is the only drug approved for long-term use.
Mindful of adding time and cost to drug development, most committee members said that some of the testing for cardiovascular risk could take place after a drug was approved. They also said drug companies might not have to do special cardiovascular trials if they can adequately assess cardiovascular risk in the trials they already do to win approval. The committee was asked to vote only for drugs with no “signal” of cardiovascular risk. The F.D.A. said during the meeting that it had already decided that cardiovascular risks must be ruled out for drugs that have such a signal, like raising blood pressure.
Qnexa from Vivus also raised heart rate, prompting some analysts to question whether that would be a signal that would delay approval. However, Qnexa lowered blood pressure. The same advisory committee last month discussed potential heart risks and recommended approval of Qnexa by a vote of 20 to 2. Committee members seemed to agree that Vivus could do a cardiovascular trial after approval. Vivus declined to comment on Thursday, saying it was in a quiet period before the F.D.A. decision, which is expected by April 17.