Wyeth and Progenics Pharmaceuticals Announce Worldwide Collaboration to Develop and Commercialize Methylnaltrexone; Methylnaltrexone in Late-Stage Clinical Development for Opioid-Induced Constipation and Post-Operative Bowel Dysfunction

Business Wire, Dec 23, 2005

MADISON, N.J. & TARRYTOWN, N.Y. -- Wyeth Pharmaceuticals, a division of Wyeth (NYSE:WYE) and Progenics Pharmaceuticals, Inc. (Nasdaq: PGNX) today announced that they have entered into an exclusive, worldwide agreement for the joint development and commercialization of methylnaltrexone (MNTX) for the treatment of opioid-induced side effects, including constipation and post-operative bowel dysfunction. These medical conditions are major therapeutic challenges in the management of gastrointestinal function in individuals treated with opioids for pain or in patients following serious or prolonged surgeries.

Under the terms of the collaboration, Wyeth receives worldwide rights to MNTX, and Progenics retains an option to co-promote the product in the United States. The companies will collaborate on the worldwide development of MNTX. The transaction includes an upfront payment of $60 million to Progenics with as much as an additional $356.5 million payable upon achievement of certain milestones. Wyeth will pay Progenics royalties on worldwide sales of MNTX and co-promotion fees within the United States. Additionally, Wyeth is responsible for all future development and commercialization costs.

"MNTX fits well within our current portfolio and represents a broad treatment platform with multiple products intended to address unmet medical needs in opioid-induced bowel disorders," says Bernard Poussot, President of Wyeth Pharmaceuticals and Executive Vice President, Wyeth. "Our collaboration with Progenics strengthens Wyeth's leadership position in the field of gastroenterology. Importantly, within Wyeth, we have selected MNTX for streamlined development."

"Our collaboration with Wyeth maximizes the global development, commercialization, and market potential of MNTX across a broad range of therapeutic indications," says Paul J. Maddon, M.D., Ph.D., Progenics' Founder, Chief Executive Officer and Chief Science Officer. "Progenics and Wyeth share a vision for bringing this important new therapy to market for the millions of patients who suffer from the debilitating side effects of opioid pain medications."

Currently, there are no therapies approved to treat the side effects of opioids. These side effects often prevent optimal pain control and may prolong hospitalization. The ability to deliver MNTX using three dosage forms and routes of administration represents a significant benefit to patients and health care professionals. Each MNTX dosage form is tailored to address the needs of specific clinical applications based on onset of action, predictability of response, dosing flexibility and ease of use. The three MNTX product candidates are:

--Subcutaneous injection for the treatment of intractable constipation in patients with advanced medical illness (AMI), including cancer and AIDS;

--Intravenous infusion for the treatment of patients with gastrointestinal tract and urinary dysfunction that commonly occurs after major abdominal and prolonged surgeries; and

--Oral formulation for the treatment of opioid-induced constipation in patients with chronic pain, including those suffering from headaches, joint pain, lower-back pain, sickle-cell disease, muscle pain and other disorders requiring opioid analgesics.

Progenics is completing a second pivotal phase 3 clinical study of subcutaneous MNTX in AMI. In 2006, clinical studies in post-operative bowel dysfunction with intravenous MNTX are scheduled to enter phase 3, and the oral product will enter phase 2 in patients receiving opioids for chronic pain. Under the terms of the collaboration, Wyeth will develop oral MNTX worldwide. Progenics will lead the U.S. development of subcutaneous and intravenous MNTX, while Wyeth will lead development of these parenteral products outside the U.S. Wyeth and Progenics will pursue an integrated strategy to optimize worldwide development, regulatory approval, and commercial launch of the three MNTX products which may impact timelines previously disclosed by Progenics. Decisions regarding the timelines for development of the three MNTX products will be made by the Joint Development Committee, consisting of members from both Wyeth and Progenics.

Background

Opioids are widely used to lessen suffering in advanced cancer and other terminal diseases. To relieve pain, narcotic medications such as morphine activate specific opioid receptors located in the central nervous system - the brain and spinal cord. Opioids, however, also interact with these receptors outside of the central nervous system, resulting in side effects, which can be debilitating, including constipation, urinary retention and severe itching. MNTX is designed to block peripheral opioid receptors whose activation causes these side effects. As MNTX does not cross the blood-brain barrier, it does not interfere with brain-centered pain relief.

--Advanced medical illness: Approximately 1.7 million patients suffer from AMI each year in the U.S., including patients with cancer, AIDS, sickle-cell disease and other painful terminal illnesses. The majority of those treated with opioids for pain suffer debilitating constipation.