FDA panel rejects Eisai weight-loss drug

An advisory committee to the US Food and Drug Administration voted on Thursday to recommend that the federal agency deny approval of a new weight-loss drug being developed through a partnership between Eisai and Arena Pharmaceuticals.

The Endocrinologic and Metabolic Drugs Advisory Committee voted nine-to-five that the data submitted in the companies' marketing application for lorcaserin do not show that the drug's benefits outweigh its risks.

Lorcaserin is a selective serotonin 2C receptor agonist intended to act in the area of the brain that is believed to control appetite and metabolism. The New Drug Application (NDA) submitted for the product included data from 18 clinical trials showing that overweight and obese people who took the drug and followed a behavioural programme for a year lost at least five per cent of their body weight.

However, many of the advisors on the panel felt that the weight loss was not great enough to justify approval, particularly in light of various safety concerns, which include evidence showing an increase in breast tumours in lab animals.

Arena, which developed lorcaserin, stood by the drug. "We believe that lorcaserin has a positive benefit-risk profile and represents a potential advance in the treatment of obesity," said Jack Lief, president and CEO. "We will work with the FDA as the agency completes its review of the lorcaserin New Drug Application."

The FDA is not required to follow the advice of its outside advisors, but often does so. In this case, the opinion of the panel members who voted against approval echoed the position taken in briefing documents prepared by FDA staff members in advance of the meeting, which also questioned lorcaserin's risk-benefit profile.

The FDA is aiming to complete its review of the NDA for the drug by October 22 of this year.

The Endocrinologic and Metabolic Drugs Advisory Committee also evaluated the risk-benefit profile of Abbott's marketed weight-loss drug Meridia (sibutramine) and was split eight-to-eight in a vote on whether the drug should be allowed to remain on the market amid recent concerns about potential cardiovascular risks.

Of the eight panel members who voted to keep the drug on the market, six said they were only in favour of continued marketing if stronger safety measures were enacted.

"Today's vote highlights the complexity of this scientific debate," Eugene Sun, vice president, Global Pharmaceutical Development, said in a statement from Abbott on the vote. "We continue to believe that there are appropriate and identifiable patients that derive benefit from sibutramine. Sibutramine is an important option for patients and physicians to treat a serious condition for which there are few treatment options currently available."

Even if the drug is eventually pulled from the market, it should not have a significant effect on Abbott's bottom line. Sales of Meridia are expected to come in at about $30m this year, meaning that it is not one of the company's top-selling products.