Orexigen weight-loss drug shows positive results in study

Results from COR-I, one of the Phase III trials supporting the NDA for Orexigen Therapeutics' (NASDAQ: OREX) weight-loss drug Contrave, show that patients taking the drug were two to three times more likely to lose at least 5 or 10 percent of their body weight compared with those taking placebo. The study results have been published online in the journal Lancet.  

Treatment with Contrave also resulted in significant improvements versus placebo in waist circumference, insulin resistance, HDL cholesterol, triglycerides and hsCRP, which are accepted measures of cardiometabolic risk. Patients taking Contrave also showed significant improvements in patient-reported control of eating, the company says in a statement.

But, as Reuters points out, only half the volunteers finished the trial, dropping out for various reasons. "The people in the placebo group seemed to drop out more frequently because they were dissatisfied with the lack of weight loss. People in the drug arm seemed to drop out more because of side-effects. Overall, the groups seemed to be equal," Frank Greenway, who led the trial, tells Reuters. The most frequent adverse event in participants taking Contrave was nausea. Headache, constipation, dizziness, vomiting and dry mouth were also more frequent in those taking the drug than in the placebo group, according to the study results.

Orexigen is one of three company trying to get weight-loss drugs to the market. Earlier this month, an expert panel recommended against approval of Vivus' (NASDAQ: VVUS) competing drug Qnexa. The vote was six in favor and ten against, with many of the no voters citing the need for more safety data.  As Bloomberg points out, some of the panelists' safety concerns have plagued other weight-loss drugs. For example, Abbott Laboratories pulled Meridia from the European market over concerns about heart risks in January.

Orexigen's other rival, Arena Pharmaceuticals (NASDAQ: ARNA), recently released promising data for its own obesity drug, lorcaserin. Results showed that just about half of the patients taking the drug in a two-year trial lost at least five percent of their body weight--roughly twice the rate of weight loss registered in the placebo group.

The FDA has tentatively scheduled a Division of Metabolic and Endocrine Drug Products Advisory Committee meeting for Dec. 7, and the Prescription Drug User Fee Act action date has been set for Jan. 31, 2011. 

- see the Orexigen release
- here is a summary of the study in the Lancet
- read the Reuters story
- get more from Bloomberg