FDA shoots down another weight-loss drug

The FDA has told the makers of the proposed weight-loss drug Lorcaserin that it will not at this time approve marketing of the medication, citing concerns about its marginal effectiveness and about cancers that occurred at higher-than-usual rates during clinical trials.

Lorcaserin: An article in the Oct. 24 Section A on the denial of Food and Drug Administration approval of the experimental weight-loss drug Lorcaserin said the FDA was concerned about cancers that occurred during clinical trials. As indicated later in the article, the cancers occurred in studies of animals. —

The decision comes two weeks after the makers of the prescription diet pill Meridia pulled it from the U.S. and Canadian markets at the request of the FDA.

The action on Lorcaserin is the first signal of how the U.S. drug agency will deliberate on a trio of new weight-loss drugs proposed for the U.S. market, where about one in three adults are obese.

Arena Pharmaceuticals, the San Diego company that has developed Lorcaserin in partnership with Eisai Co., released the contents of an FDA letter Saturday in which the agency outlined its concerns. Among them were weight-loss results that failed to rise to the FDA’s standards for approval and a worrisome increase in cancerous breast and brain tumors in rats that were given a dose higher than that proposed for humans.

A clinical trial of Lorcaserin published in the New England Journal of Medicine found that two-thirds of patients lost at least 5% of their body weight, while a third lost at least 10%, with an average loss of 17 to 18 pounds.


With the results of a new clinical trial on Lorcaserin for obese patients with Type-2 diabetes due to be unveiled in the coming weeks, Arena Pharmaceuticals officials said they will meet with FDA officials to address the agency’s concerns.

The company held out hope those results will prompt a change of heart at the FDA. “This is an important step for us toward the FDA’s approval of Lorcaserin,” said Jack Lief, Arena’s president and chief executive.

Qnexa got a thumbs-down recommendation in June from an FDA advisory panel, and the agency is expected to issue a decision on the drug this week. Another drug, Contrave, is to be considered by an FDA advisory panel in December.