Orexigen slips after release of early Contrave study data draws report of FDA criticism

Shares of Orexigen Therapeutics sank in premarket trading Friday, giving back some of the gain they netted this week after the company announced encouraging early data from a study of its weight-loss drug Contrave.

The La Jolla, California, drugmaker's stock had soared after it said Tuesday that a patient group taking Contrave had fewer serious cardiovascular problems than those who took a placebo or fake drug, according to an early analysis of a study. That announcement, which came in a Securities and Exchange Commission filing, drew a rebuke from the Food and Drug Administration.

A report on Forbes.com said Thursday that an FDA official noted that interim study results are highly unreliable. Dr. John Jenkins, the FDA's director of the Office of New Drugs, also said that the results must be kept confidential to avoid compromising the trial's integrity so researchers can get a clear sense of any cardiovascular risk that comes with the drug.

The report added that the agency also is concerned about doctors and patients making health care decisions based on unreliable data.

The FDA approved Contrave last September after first rejecting the drug in 2011 due to cardiovascular risk concerns. Orexigen had reapplied after performing another analysis designed to rule out heart problems.

Shares of Orexigen Therapeutics Inc. had jumped more than 46 percent from Monday to Wednesday's market close. But the stock started falling Thursday and was down nearly 16 percent, or $1.28, to $6.73 in premarket trading about 45 minutes before markets opened.