FDA panel rejects diet drug

A weight-loss drug that was expected to be a blockbuster failed to gain approval yesterday from a key advisory committee to the Food and Drug Administration because it appears to increase the risk of suicidal tendencies.

The advisory committee’s unanimous decision is a significant setback for the drug. But the final say on whether Sanofi-Aventis SA will be allowed to sell Zimulti by prescription in the United States will be made by the FDA late next month. The agency isn’t required to follow the advice of its outside advisers, but it does so most of the time.

“There is a reasonable suspicion we better learn some more and watch this affair more closely before we launch into massive use of this drug,” said panelist Dr. Jules Hirsch, of the Rockefeller University.

The drug is seen as a potential blockbuster because obesity rates have exploded in the U.S. in the past two decades. Today, nearly one in three Americans 20 or older is obese, according to Centers for Disease Control and Prevention.

Seeking to limit damage from findings of increased risk of suicide, company officials appeared open to stern warnings on the drug’s label after suggesting that prospective users be screened for depression. They also advised that patients visit their doctors five times during the first year of treatment to be reassessed.

Sanofi-Aventis’ Richard Gural, vice president for regulatory development, told the advisory committee that the drug is not appropriate for anyone with a history of depression or suicidal thoughts or who has been diagnosed with depression or is taking antidepressants.

But the FDA said the drug’s side effects can reach more people. Amy Egan, a FDA medical officer, told the committee that 88 percent of those reporting psychiatric problems while on the drug had no history of depression.

“We strongly believe that it is causal,” Dr. Egan said.

When used in conjunction with a modest-calorie diet and physical exercise, Zimulti significantly reduces body weight in overweight or obese patients, according to Sanofi-Aventis. In yearlong studies, patients on the drug lost about 14 pounds. The FDA does not dispute the drug’s weight-loss capability.

Zimulti is sold in Europe under the name Acomplia. An FDA spokeswoman said the agency is aware of one suicide, which occurred last week, associated with the drug.

There are two FDA-approved prescription drugs for the long-term treatment of obesity: Meridia, made by Abbot Laboratories, is an appetite suppressant, and Xenical, made by Roche Laboratories, limits the amount of fat the body can absorb. Sales of Alli, a lower-dose version of Xenical that won’t require a prescription, start this week.