Amgen Wins TKT Appeal| Amgen

Amgen Wins TKT Appeal

THOUSAND OAKS, Calif.--(BUSINESS WIRE)--Aug. 3, 2006--Amgen (NASDAQ:AMGN) today issued the following statement:

The Court of Appeals for the Federal Circuit today affirmed the District Court's decision that Transkaryotic Therapies Inc. (TKT) and Aventis Pharmaceuticals Inc. infringe Amgen's erythropoietin (EPO) patent estate.

Today's ruling reaffirms Amgen's confidence in the strength of its intellectual property portfolio. The court's decision upheld the validity of two of Amgen's EPO patents. In this decision and in prior rulings, this court has upheld infringement by TKT of three patents and 12 claims, including a patent that does not expire until 2015.

This appeal reviewed the District Court's findings on the infringement and validity of two patents with claims to the production of erythropoietin, the infringement of one product patent under the doctrine of equivalents, and the validity of one product patent. The Federal Circuit found the production patents valid and infringed (U.S. Patent Nos. 5,618,698 and 5,756,349). The court reversed the District Court's determination that TKT infringed Amgen's U.S. Patent No. 5,621,080 under the doctrine of equivalents, and remanded to the District Court for further consideration of the remaining validity issue on one of the other product patents (U.S. Patent No. 5,955,422).

The pioneering inventions made by Amgen as described in these EPO patents revolutionized anemia treatment and provided products that have made dramatic differences in the lives of patients since the introduction of EPOGEN(R) in 1989. EPOGEN along with Aranesp(R) have accumulated over 4 million combined patient years of experience. Amgen continues to invest heavily in meaningful research to improve the lives of patients with kidney, cancer and cardiovascular disease.

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Marie Fay, 805-447-0081 (Media)
Arvind Sood, 805-447-1060 (investors)