THOUSAND OAKS, Calif.--(BUSINESS WIRE)--Nov. 9, 2005--Amgen (NASDAQ:AMGN), the world´s largest biotechnology company, today announced that it filed a lawsuit in the United States District Court in Boston, Massachusetts against F. Hoffmann-LaRoche Ltd., Roche Diagnostics GmbH, and Hoffmann-LaRoche, Inc., seeking a declaration by the Court that defendants´ importation, use, sale or offer to sell a pegylated version of recombinant human erythropoietin infringe Amgen´s patents. Amgen alleges infringement of six U.S. patents owned by Amgen that claim erythropoietin (EPO) products and pharmaceutical compositions, and processes for making EPO. Amgen seeks a permanent injunction preventing the defendants from making, importing, using, offering for sale or selling recombinant human EPO, including pegylated EPO, in the United States.

Amgen markets a recombinant human EPO product in the United States as EPOGEN(R) (Epoetin alfa) for the treatment of anemia associated with chronic renal failure for patients on dialysis. Amgen´s patent rights on erythropoietin protect Amgen´s breakthrough inventions.

About EPOGEN(R) (Epoetin alfa)

EPOGEN (Epoetin alfa) is indicated for the treatment of anemia in patients with chronic renal failure on dialysis. EPOGEN is contraindicated in patients with uncontrolled hypertension. For additional product information, please see www.Epogen.com.

About Amgen

Amgen discovers, develops and delivers innovative human therapeutics. A biotechnology pioneer since 1980, Amgen was one of the first companies to realize the new science´s promise by bringing safe and effective medicines from lab, to manufacturing plant, to patient. Amgen therapeutics have changed the practice of medicine, helping millions of people around the world in the fight against cancer, kidney disease, rheumatoid arthritis, and other serious illnesses. With a broad and deep pipeline of potential new medicines, Amgen remains committed to advancing science to dramatically improve people´s lives. To learn more about our pioneering science and our vital medicines, visit www.amgen.com.

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CONTACT: Amgen, Thousand Oaks Mary Klem, 805-447-4587 (media) Arvind Sood, 805-447-1060 (investors) SOURCE: Amgen