The FDA requested the market withdrawal after reviewing data from the Sibutramine Cardiovascular Outcomes Trial (SCOUT). SCOUT was initiated as part of a postmarket requirement to look at cardiovascular safety of sibutramine after the European approval of this drug. The trial demonstrated a 16 percent increase in the risk of serious heart events, including non-fatal heart attack, non-fatal stroke, the need to be resuscitated once the heart stopped, and death, in a group of patients given sibutramine compared to another given placebo. There was a small difference in weight loss between the placebo group and the group that received sibutramine.

"The patients in the European SCOUT trial did not have the same characteristics as the patients for the approved indication in the United States; however, these results, combined with other available safety data raised serious questions about Meridia's safety for all patient groups," said Gerald Dal Pan, M.D., M.H.S., director of the Office of Surveillance and Epidemiology in CDER.

The agency's analysis of SCOUT was the subject of the FDA's Endocrinologic and Metabolic Drugs Advisory Committee meeting on Sept. 15.