Orexigen and partner Takeda will be breathing a sigh of relief after advisors to US regulators gave the thumbs up for approval of Contrave, potentially the first new diet pill to hit the market in a decade.

The US Food and Drug Administration’s Endocrinologic & Metabolic Drugs Advisory Committee voted 13-7 that the benefits of Contrave (bupropion/naltrexone) outweigh the risks in patients who need to loose weight.

Things were looking a little shaky for the drug after documents released ahead of the meeting yesterday drew attention to a small but statistically significant increase in blood pressure and heart rate, as well as a question mark over whether the drug was effective enough and met the FDA’s 5% weight loss target.

The advisors noted that patients treated with Contrave in clinical trials lost 4.2% more of their weight than those on placebo after 56 weeks, falling below the agency's 5% threshold, but added that about twice as many patients on the combo shed at least 5% more of their weight than those on placebo, thereby meeting the guidelines.

And with regard to concerns over cardiovascular safety, the Committee voted (11-8) that this could be addressed by a dedicated study to further examine the drug's effect, and that study can be conducted following marketing approval, paving the way for a full green light by the FDA.

No new weight loss drugs have been cleared for US use since Roche's Xenical (orlistat) in 1999, and there are hopes that Contrave, which, according to the drugmakers, appears to address both biological and behavioural drivers of obesity, will become an important new treatment options for overweight patients.