Progenics Pharmaceuticals, Inc. (Nasdaq:PGNX) and Salix Pharmaceuticals, Ltd. (Nasdaq:SLXP) today announced that they have entered into an exclusive worldwide (except Japan) agreement by which Salix has licensed rights to RELISTOR ® (methylnaltrexone bromide). RELISTOR Subcutaneous Injection is indicated for the treatment of opioid-induced constipation (OIC) in patients with advanced illness who are receiving palliative care, when response to laxative therapy has not been sufficient. Use of RELISTOR beyond 4 months has not been studied.

RELISTOR is a peripherally acting mu-opioid receptor antagonist that counteracts the constipating effects of opioid pain medications in the gastrointestinal tract without affecting their ability to relieve pain. The methylnaltrexone license includes intellectual property from the University of Chicago, Progenics Pharmaceuticals, and Wyeth Pharmaceuticals, including patents and applications with expiration dates that will range from 2017 through 2031. RELISTOR was approved in the United States in 2008, and currently the drug is approved for use in over 50 countries worldwide. In 2010, RELISTOR single-use, pre-filled syringes were approved for use in the United States, Canada and the European Union. Worldwide net sales of RELISTOR totaled $16 million in 2010.

Financial terms of the transaction include a $60 million up-front payment and development milestones totaling $90 million, contingent upon the achievement of certain U.S. regulatory milestones. Salix also will pay sales-based milestones of up to $200 million plus royalties on product sales in the U.S., as well as 60% of all revenue received from non-U.S. sublicensees. Salix will fund all development, registration and commercialization activities for RELISTOR in markets worldwide other than in Japan, where Progenics has licensed to Ono Pharmaceuticals the rights to develop and commercialize subcutaneous RELISTOR.

Commenting on the transaction, Mark R. Baker, President, Progenics, stated, “Our agreement with Salix represents the culmination of our search for a partner with the skills, experience and passion to effectively market and develop RELISTOR. With the strength of Salix’s sales force and development team behind this product, I believe that RELISTOR’s full potential can be achieved -- to the benefit of OIC patients.”