The FDA has accepted for review an NDA from Progenics Pharmaceuticals and Wyeth for subcutaneous methylnaltrexone for the treatment of opioid-induced constipation (OIC) in patients receiving palliative care. The FDA has set a Prescription Drug User Fee Act (PDUFA) date of January 30, 2008, to complete its review of the NDA. The companies also announced that the European Medicines Agency (EMEA) has validated for review Wyeth's Marketing Authorization Application (MAA) for the treatment.

Methylnaltrexone, an investigational drug, is a peripherally acting opioid-receptor antagonist that is designed to treat OIC without interfering with pain relief. There currently is no approved medication that specifically targets the underlying cause of OIC to relieve constipation in this patient population. The acceptance of the NDA submission results in a $5 million milestone payment to Progenics by Wyeth. Progenics previously earned a $4 million milestone payment from Wyeth based on the validation for review in the EU, as announced previously.

In December 2005, Wyeth and Progenics entered into an exclusive, worldwide agreement for the joint development and commercialization of methylnaltrexone for the treatment of opioid-induced side effects, including constipation and post-operative ileus (POI), a prolonged dysfunction of the gastrointestinal (GI) tract following surgery. Under the terms of the agreement, the companies are collaborating on worldwide development. Wyeth received worldwide rights to commercialize methylnaltrexone, and Progenics retained an option to co-promote the product in the U.S. Wyeth will pay Progenics royalties on worldwide sales and co-promotion fees within the U.S.