Progenics Pharmaceuticals Inc. picked up a $15 million up-front payment in a deal in which Ono Pharmaceutical Co. Ltd., of Osaka, Japan, gained rights to Relistor in Japan, where it plans to commercialize the drug for the treatment of opioid-induced constipation.

Under the agreement, Ono is responsible for developing and commercializing subcutaneous Relistor in Japan, including conducting the needed clinical trials and obtaining marketing approval. In addition to the $15 million up-front payment, Progenics could receive up to an additional $20 million upon achievement of development milestones. Ono also will pay Progenics royalties and commercialization milestones on sales by Ono.

Ono also obtained the option to acquire from Progenics the rights to develop and commercialize in Japan other formulations of Relistor, including intravenous and oral forms, on terms to be negotiated separately.

Progenics originally granted worldwide rights for Relistor to Madison, N.J.-based Wyeth under a 2005 agreement. Wyeth, however, elected not to develop the drug in Japan, returning those rights to Progenics. Wyeth retains its licensed rights elsewhere in the world.

Wyeth's decision not to proceed with the drug in Japan took it off the hook for potential milestone payments to Progenics totaling $22.5 million (of which $7.5 million related to the subcutaneous formulation and the remainder to the intravenous and oral formulations).

Progenics, of Tarrytown, N.Y., said it now has the potential to receive a total of $334 million in development and commercialization milestone payments from Wyeth under the 2005 agreement, of which $39 million have been paid to date.

Sales of subcutaneous Relistor began earlier this year in the U.S., Canada and Europe following regulatory approvals in each area.

Progenics and Wyeth continue to collaborate on development of an intravenous formulation of Relistor in post-operative ileus and an oral formulation for opioid-induced constipation in patients with chronic pain.

A Phase III trial in patients with postoperative ileus did not meet any of the study goals, but a Phase II study of oral Relistor showed some benefit in treating opioid-induced constipation in patients with chronic, non-malignant pain. (See BioWorld Today, May 23. 2008.)

Shares of Progenics (NASDAQ:PGNX) dropped 45 cents to close at $10.42 on Friday.