Shares in Arena Pharmaceuticals increased in price by 80% after advisors to the FDA backed the approval of the obesity drug lorcaserin.

The FDA’s Endocrinologic and Metabolic Drugs Advisory Committee voted in favour of recommending lorcaserin after deciding data demonstrated that benefits outweighed long-term risks.

Jack Lief, Arena CEO, said the decision “supports our belief in lorcaserin as a potential new treatment option for the medical management of overweight and obesity”.

The Prescription Drug User Fee Act (PDUFA) date for the FDA’s final decision on lorcaserin is now expected on 27 June.

Lorcaserin was initially rejected by the FDA back in 2010 when concerns were raised over its clinical effectiveness and around its side-effects.

Arena refiled the drug at the end of 2011 with new data ruling out excessive risk of valvular heart disease.

The decision on Lorcaserin comes a month after the same committee supported the use of Vivus’ rival obesity drug Qnexa (phentermine/topiramate) with its PDUFA data extended from April 17 to July 17.

Contrave (naltrexone/bupropion), another rival weight loss drug from Orexigen Therapeutics and Takeda, is currently being evaluated in a cardiovascular outcomes trial after it was rejected by the FDA over heart risks.

After the positive decision by the FDA’s advisors, Arena and its marketing partner Eisai expanded their marketing and supply agreements for the treatment to cover the US, Canada, Mexico and Brazil.

Arena Pharmaceuticals has moved a step closer to gaining a licence for its obesity drug lorcaserin after submitting marketing authorisation applications with the EMA and FDA.

The applications are intended to gain an indication to treat weight control, including weight loss and the maintenance of weight loss, in obese or overweight patients with at least one weight-related co-morbid condition.

Craig Audet, Arena’s Vice President of Global Regulatory Affairs, says the company is working “diligently” to prepare for the FDA’s Advisory Committee meeting in May.

If lorcaserin were to be approved in the US, it would be the first new obesity drug to reach the lucrative American market in more than a decade.

The biopharmaceutical company and its marketing partner Eisai – who has exclusive rights to market and distribute the treatment in the US – previously failed to gain a licence in the US in 2010.

The FDA declined to approve lorcaserin in October 2010 when it cited a number of issues, including insufficient evidence of its efficacy and safety.

Lorcaserin faces a race to win approval against Vivus’ rival weight loss drug Qnexa after FDA advisors voted in favour of its use. It may now be approved as early as next month.