WASHINGTON – The U.S. Food and Drug Administration 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.
The FDA’s 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 one-in-three adults is 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 those concerns 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 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 percent of their body weight, while a third lost at least 10 percent of body weight, with an average loss of 17 to 18 pounds.