Amgen Is Cleared to Buy Immunex

Amgen Inc., the world’s largest biotechnology company, won U.S. antitrust clearance Friday to complete its $9.6-billion purchase of Immunex Corp., maker of a leading rheumatoid arthritis drug.

Amgen and Immunex received Federal Trade Commission approval for the takeover after the companies agreed to grant patent licenses to allow development of two rival anti-arthritis drugs to address FTC concerns that the acquisition would hurt competition and lead to higher drug prices.

The two companies previously agreed to sell Immunex’s Leukine infection-fighting drug to Schering.

As part of the purchase, Amgen will receive Immunex’s Enbrel, a rheumatoid arthritis drug it predicts will have sales of at least $3 billion. Amgen will market Enbrel along with its own arthritis medication, Kineret.

The FTC said Regeneron Pharmaceuticals Inc. received a license from Amgen and Immunex to use a patent for developing a rheumatoid arthritis drug to combat the same inflammation-causing protein as Amgen’s Kineret treatment.

The companies also agreed to grant another patent license to develop a drug that blocks TNF, or tumor necrosis factor, the FTC said. Enbrel also targets TNF, the immune system protein linked to inflammation and tissue destruction.

Amgen, based in Thousand Oaks, said in December that it would pay 0.44 share of Amgen plus $4.50 in cash for each share of Immunex, based in Seattle.

Immunex introduced Enbrel in 1998, and the drug’s quick acceptance in the market forced the company to begin building a new production plant in Rhode Island to alleviate shortages. Amgen says it expects to begin production there in January, several months after the date first projected by Immunex.

Wyeth Inc., which markets Enbrel, owns 40% of Immunex and will own 10% of the combined company, according to Hoover’s Inc.

Shares of Amgen, which have dropped 42% since it announced the Immunex takeover Dec. 17, fell 11 cents to $34.30 Friday on Nasdaq.

Immunex shares, which have dropped 33% during the same period, rose 5 cents to $19.55, also on Nasdaq.