November 25, 2010
1 min read

FDA rejects lorcaserin for weight-loss therapy

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The FDA has completed its review of the new drug application for lorcaserin, an investigational selective serotonin 2C receptor agonist, and determined that it cannot approve the weight-loss drug in its present form.

In its complete response letter to Arena Pharmaceuticals, the agency outlined clinical and nonclinical reasons for its decision, citing “diagnostic uncertainty in the classification of mammary masses in female rats, unresolved exposure-response relationship for lorcaserin-emergent mammary adenocarcinoma and unidentified mode of action and unclear safety margin for lorcaserin-emergent brain astrocytoma,” according to a company press release.

The FDA stated that the weight-loss efficacy of lorcaserin (Lorqess, Arena Pharmaceuticals) in overweight and obese individuals without type 2 diabetes is marginal, and recommended that the company submit the final study report of the Behavioral Modification and Lorcaserin for Overweight and Obesity Management in Diabetes Mellitus (BLOOM-DM) trial. The BLOOM-DM trial evaluated lorcaserin vs. placebo during a 1-year treatment period in obese and overweight patients with type 2 diabetes.

In its letter, the FDA also requested a detailed accounting of slides prepared from female rats that contributed to mammary tumor incidence data and an independent pathologist readjudication of all mammary and lung tissues from female rats, among other requests related to nonclinical issues. The agency stated that in the event evidence cannot be provided to alleviate concern regarding clinical relevance of the tumor findings in rats, additional clinical studies may be required.

Lorcaserin is intended for weight management, including weight loss and maintenance, in obese patients with a BMI of 30 or greater or in overweight patients who have at least one weight-related comorbid condition.

On Oct. 1, by a 9-5 vote, the FDA Endocrinologic and Metabolic Drugs Advisory Committee voted against approval of lorcaserin as a weight-loss drug for obese patients. The committee cited concerns regarding potential risks of neoplasms and valvular heart disease associated with the drug.