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.

Arena Pharmaceuticals is set to welcome Robert Hoffman, their former Vice President, Finance and Chief Financial Officer, back to the company.

Mr Hoffman will rejoin at the end of August to the position he departed back in March to join Polaris Pharmaceuticals.

Jack Leif, President and CEO, Arena, says Robert has been a “key contributor” in the past and his return “comes at an important time” for the company.

Prior to leaving Arena, Mr Hoffman served as Controller, Vice President, Finance and then Vice President, Finance and Chief Accounting Officer before his most recent role after joining the company back in 1997.

“I look forward to again working closely with my colleagues to support Arena's efforts to seek FDA approval of lorcaserin and to advance select earlier-stage research and development programs,” said Mr Hoffman.

In addition to his future role at Arena, Mr Hoffman also serves as a member of the Financial Accounting Standards Board’s small business advisory committee and the Steering Committee of the Association of Bioscience Financial Officers. He is also a former Director and President of the San Diego Chapter of Financial Executives International.

Arena Pharmaceuticals is searching for a new chief finance officer after Robert Hoffman resigned from his role.

Mr Hoffman has accepted another position within the healthcare industry and will leave the company in March.

Jack Lief, Arena’s President and Chief Executive Officer, thanked him for his “many years of valuable service”.

Jennifer Bielasz, Senior Director of Accounting and Controller, and Carolyn Felzer, Senior Director of Finance, will continue to play “key leadership roles”, Arena said.

“Robert has built a strong finance team at Arena, and we are focused on ensuring a smooth transition when he departs next month,” said Mr Lief.