GlaxoSmithKline and Adolor Corp have suffered a fresh setback in their bid to get approval for the investigational bowel drug Entereg after the US regulator said it needs more time to study the compound.

This is especially disappointing news for the two firms given that just over a fortnight ago, the US Food and Drug Administration accepted as complete a response from Adolor to an approvable letter issued on the treatment. Now, however, the agency has informed the companies that it needs additional time to complete its review of the submissions for the release of the clinical hold on Enterg (alvimopan).

The companies suspended trials of Entereg in April due to cardiovascular risk and two months later, the FDA placed the alvimopan Investigational New Drug applications on clinical hold, including a programme looking at the drug as a treatment for opioid induced bowel dysfunction. As a result of this latest decision, the hold for all alvimopan studies remains in effect and the FDA did not indicate a timeframe within which its review would be completed.

Entereg has been filed for the management of postoperative ileus and the agency has set a Prescription Drug User Fee Act date of February 10 next year for the NDA.

GSK increases flu vaccine supplies to USA

Meantime, GSK said that its supply to the US market of the seasonal influenza virus vaccines Fluarix and FluLaval has increased to 30-35 million doses from about 25 million in the 2006-07 flu season. David Pernock, senior vice president at the drugs major, said that over the years, GSK has significantly increased its influenza vaccine manufacturing capacity “and we have taken steps to improve the way this product is distributed to those who need it”.

GSK also announced that it is nearing completion of a two-year, $199 million investment to upgrade and expand its influenza vaccine manufacturing facility in Quebec City, Canada. The plant will now have the capacity to make 75 million doses of the vaccines per year.