The US Food and Drug Administration (FDA) has been urged to reject Arena Pharmaceuticals' experimental weight loss drug, lorcaserin, by consumer watchdog Public Citizen.
The FDA is expected to rule on the drug's approval on 27 June 2012, but Public Citizen has raised concerns over the drug's potential to increase a patient's risk of heart valve damage.
The group cited physicians present at May 2012's FDA advisory panel meeting, who raised concerns regarding evidence of increased valve disease risks in patients who participated in clinical trials of lorcaserin. Despite the concerns, the panel voted 18 to four in favour of approving the drug.
Public Citizen drew parallels between lorcaserin and fen-phen, the anti-obesity drug that was pulled from the shelves in 1997 after similar fears, whilst also questioning the drug's modest weight loss results.
Lorcaserin is one of three potential weight loss drugs currently seeking approval, with Vivus' Qnexa and Orexigen's Contrave medications, all touted as having the potential to become the first new diet pill to reach the market in over a decade.
Arena has faced a turbulent time in attempting to achieve approval for lorcaserin. The drug was first rejected in October 2010 after the FDA found potential cancer risks, although Arena resubmitted its application with more supporting data, showing that tumours found in rats given the drug would not apply to human use.
Despite disappointing falls in stock prices recently, Arena stock has risen more than 400% during 2012 in anticipation of the drug achieving approval.