Adolor has received an approvable letter from the US FDA for Entereg (alvimopan) capsules, an investigational drug under review for the management of postoperative ileus (POI) by acceleration of the time to recovery of gastrointestinal (GI) function following bowel resection surgery. The new drug application (NDA) for Entereg was submitted in June 2004, Adolor Corporation and GlaxoSmithKline jointly announced here.

According to the release, before the application may be approved, it will be necessary to provide additional proof of efficacy to the FDA to support the use of Entereg following bowel resection surgery. The FDA indicated that this may be achieved by demonstrating statistically significant results in at least one additional clinical study, and that this could potentially be addressed with positive results from Adolor's ongoing Study 14CL314. The FDA also indicated that the Company must provide justification that the median reduction in time to gastrointestinal recovery seen in bowel resection patients treated with Entereg is clinically meaningful.

"We intend to request a meeting with the FDA as quickly as possible to discuss the approvable letter and determine the appropriate next steps for the NDA," said Bruce Peacock, president and chief executive officer of Adolor Corporation.

Entereg (alvimopan) is an investigational peripherally-acting mu-opioid receptor (PAM-OR) antagonist designed to inhibit the negative effects of opioids, like morphine, on the gastrointestinal system without interfering with the analgesic effects in the central nervous system.

Adolor Corporation and GlaxoSmithKline are collaborating on the worldwide development and commercialization of Entereg for POI and opioid-induced bowel dysfunction (OBD) associated with extended use of opioids to treat chronic pain.