U.S. advisers reject Arena diet drug

U.S. advisers rejected Arena Pharmaceuticals Inc’s experimental weight-loss pill on Thursday, a major setback for the company that is trying to win approval for its most advanced drug candidate.

A committee of medical experts voted 9-5 that potential risks of the drug, lorcaserin, outweighed possible benefits from modest weight loss. Rats given high doses of the drug developed tumors, and panelists said they were unsure if cancer would increase in people.

“I do think (lorcaserin) is promising, but there’s too much uncertainty at this time,” said Jessica Henderson, the panel’s consumer representative.

The Food and Drug Administration usually follows panel recommendations. A final ruling is due Oct. 22.

Arena, a small company with no approved products, said the drug was safe at recommended doses and would help fight the U.S. obesity epidemic. Japan’s Eisai Co holds the U.S. marketing rights to lorcaserin.

The companies believe the drug has “a positive benefit-risk profile” and “will work closely with the FDA” on the review, Arena Chief Executive Jack Lief said in a statement handed to reporters shortly after the committee vote.

Trading in Arena shares was halted on Nasdaq while the panel met. Investors fled the stock earlier this week after FDA reviewers highlighted the cancer issue in an initial analysis. The company’s shares have fallen 45 percent from Monday’s close.

Consensus forecast data from Thomson Reuters shows analysts expect Arena’s drug could reach peak annual sales of $822 million if it reaches the market.

Drugmakers have failed for decades to produce a pill to help people shed a significant amount of weight without serious side effects.

Two other companies, Vivus Inc and Orexigen Therapeutics Inc, have weight-loss pills under FDA review this year. All three companies are trying to launch the first new prescription diet drug in a decade.

An FDA advisory panel rejected the Vivus diet drug in July.

###
By Lisa Richwine

ADELPHI, Md. (Reuters)