Immunex Corp. announced Wednesday that it has regainedrights to develop and market its Pixykine (PIXY321) blood-cellstimulant outside North America from Bristol-Myers Squibband is turning the rights over to American Cyanamid.

Bristol-Myers obtained the rights to market PIXY321 outsidethe U.S. and Canada under a January 1992 agreement withImmunex. At the same time, Immunex of Seattle received rights to nine oncology products from Bristol-Myers.It gained exclusive marketing rights to two of the products,Hydrea (hydroxyurea) and Rubex (doxorubicin), and co-marketing rights to seven other approved products and twoproducts that were submitted for approval to FDA. Marketingrights to these products now revert back to Bristol-Myers(NYSE:BMY).

Immunex (NASDAQ:IMNX) explained that Bristol-Myers hadthe right to terminate its agreement with Immunex and returnPixykine by Jan. 1, 1994, in the event of a change of control ofImmunex. Cyanamid acquired 53.5 percent ownership ofImmunex in December 1992 when it merged its NorthAmerican Lederle Laboratories oncology business withImmunex.

Bristol-Myers "sought to amend the agreement to permitadditional evaluation of Pixykine, but the companies could notagree on terms for such an extension," Immunex said.

Immunex's manager of communications, Mary McConnon, saidthe company estimated that 1994 product revenues from salesof Bristol-Myers' drugs would have been $30-40 million andthe cost of marketing the drugs 30 percent of this figure. Shenoted that the percentage of total Immunex sales that theproducts represent has decreased in the past year. It shrank toapproximately 20 percent in 1993 from 45 percent in 1992because of Immunex's acquisition of Lederle products, which itbegan marketing in June.

Pixykine, an interleukin-3/granulocyte macrophage-colonystimulating factor (IL-3/GM-CSF) fusion protein, acts to reducethe myelosuppressive side effects of chemotherapy bystimulating production of both white bloods cells and platelets.It is in Phase II/III trials for use as an adjunct treatment tochemotherapy. To date, more than 500 patients with a range ofmalignancies have been enrolled in U.S. trials sponsored byImmunex, and 27 patients have been tested in Europe underBristol-Myers' protocols.

Cyanamid (NYSE:ACY), which will gain an exclusive royalty-bearing license to market the drug outside the U.S. and Canada,said it expects to enroll a significant number of patients inclinical trials in Europe next year.

Shekhar Basu, an analyst with Punk, Ziegel and Knoell of NewYork, told BioWorld that the exchange of marketing rights is a"win-win situation for Immunex." He said Lederle has wantedPIXY321 for a long time and will market the product moreaggressively than Bristol-Myers. Basu said Bristol-Myers'decision was based on its competitive position with Lederlerather than on the value of PIXY321.

He also noted that Bristol-Myers dropped rights to AmgenInc.'s Neupogen (GM-CSF) in the mid-1980s because it thoughtthe drug would not be successful. According to Basu, Neupogenhad domestic revenues of $800 million in 1993, plusinternational revenues of $150-200 million.

Basu predicted that PIXY321 will take a large percentage ofNeupogen's market because of its IL-3 platelet-reducingcomponent. He said 40 percent of chemotherapy regimensreduce platelet levels in patients, resulting in bleedingcomplications.

Despite heavy trading of 1.7 million shares on Wednesday,Immunex's stock price closed unchanged at $15.50 per share.

-- Brenda Sandburg News Editor

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