Last week, Japanese drugmaker Takeda (Osaka, Japan) struck a deal with biopharmaceutical company Orexigen (La Jolla, CA) for the commercialization of its investigational obesity drug Contrave (naltrexone SR/bupropion SR). Under the terms of the agreement, Takeda will pay Orexigen $50 million cash up front, more than $1 billion in milestone payments, and royalties for rights to commercialize the drug in the US, Canada, and Mexico (Orexigen will co-promote the drug in the US).

The drug is a combination of naltrexone, which is used to fight cravings in addiction treatment, and the antidepressant bupropion. Contrave is designed to focus on the body’s metabolism and to regulate reward-based eating behavior. The drug is scheduled for review by the US Food and Drug Administration’s Endocrinologic and Metabolic Drugs Advisory Committee on Dec. 7, 2010, and the agency will decide whether to approve it by Jan. 31, 2011.

The Contrave deal is similar to a pact formed in July by Japan’s Eisai (Tokyo) and Arena Pharmaceuticals (San Diego) for the marketing of Arena’s appetite-curbing drug candidate lorcaserin hydrochloride. Under that deal, Arena will receive $50 million up front and could get more than one-third of Eisai’s net sales and up to $1.37 billion in other payments if the drug is approved. FDA’s advisory panel will meet next Thursday to discuss lorcaserin, and FDA will decide the drug’s fate by Oct. 22, 2010.

Lorcaserin is a new compound, not a combination of existing drugs. In mid-July, Arena and Eisai announced that results from the two-year BLOOM (Behavioral modification and Lorcaserin for Overweight and Obesity Management) clinical trial showed that lorcaserin used in conjunction with behavioral modification caused significantly greater weight loss and improved maintenance of weight loss compared to placebo. The study was published in the New England Journal of Medicine.  

A third potential obesity drug, Qnexa (phentermine/topiramate) by Vivus (Mountain View, CA), is under FDA review. The advisory panel recommended on July 15, 2010, that the appetite-controlling drug should not be approved because of safety concerns. FDA, which is not required to follow the advice of its advisory panels, has until Oct. 28, 2010, to decide whether to approve the drug.

See related PharmTech articles:

FDA Mulls More Obesity Drugs (PharmTech)

Report: Obesity Rates Hit More Than 25% in Most of America (blog post)