The US Food and Drug Administration (FDA) extended by three months its review of the New Drug Application (NDA) for a constipation treatment filed by Progenics Pharmaceuticals, Inc and Wyeth Pharmaceuticals.

The FDA's revised action date for methylnaltrexone, currently being reviewed for the treatment of opioid-induced constipation (OIC) in patients receiving palliative care, is now April 30, 2008.

The FDA, in its review of this NDA, requested the results from a recently completed QT study of intravenous methylnaltrexone, which is being developed for the management of post-operative ileus (POI). This study, which was submitted to the FDA, reported that there was no evidence of an effect of methylnaltrexone on QT prolongation. The FDA recently notified Progenics that it needs the extended time to review fully this study.

"We, along with our collaborator, Wyeth, are confident in our subcutaneous methylnaltrexone submission," said Paul J. Maddon, M.D., Ph.D, founder, chief executive officer and chief science officer, Progenics Pharmaceuticals, Inc. "We are enthusiastic about the entire methylnaltrexone program and plan to submit an NDA for the intravenous formulation of methylnaltrexone for the management of post-operative ileus later this year."

Methylnaltrexone is a peripherally acting mu-opioid receptor antagonist designed to mitigate the side effects of opioids on peripheral receptors without interfering with pain relief in the central nervous system (CNS) - the brain and spinal cord. Methylnaltrexone is being developed in subcutaneous and oral forms to treat OIC as well as an intravenous form for the management of POI.

In March 2007, Progenics submitted a new drug application (NDA) to the FDA for subcutaneous methylnaltrexone, followed in May 2007 by Wyeth's submission of a marketing authorization application in Europe to the EMEA. The MAA has been validated, and the EMEA review is expected to occur in 2008. Similarly, in August 2007, Wyeth submitted a marketing application to the Therapeutic Goods Administration division of the Australian government for methylnaltrexone.

Methylnaltrexone is being developed in two additional formulations: an oral form to treat OIC and an intravenous form for the management of POI, a prolonged dysfunction of the gastrointestinal tract following surgery. The companies have completed enrolment in two pivotal phase III clinical trials of intravenous methylnaltrexone in POI and have ongoing phase II studies of oral methylnaltrexone for OIC. In mid-2008, the companies plan to submit a New Drug Application to the FDA for intravenous methylnaltrexone for the treatment of POI.

Wyeth Pharmaceuticals has leading products in the areas of women's health care, infectious disease, gastrointestinal health, central nervous system, inflammation, transplantation, hemophilia, oncology, vaccines and nutritional products.

Progenics Pharmaceuticals, Inc., of Tarrytown, NY, is a biopharmaceutical company focusing on the development and commercialisation of innovative therapeutic products to treat the unmet medical needs of patients with debilitating conditions and life-threatening diseases.