TREAT Study Highlighted in March American Heart Journal

THOUSAND OAKS, Calif.--(BUSINESS WIRE)--March 28, 2005-- Amgen Inc. (Nasdaq:AMGN), the world´s largest biotechnology company, today announced that TREAT (Trial to Reduce Cardiovascular Events with Aranesp(R) Therapy), an Amgen-sponsored trial, is featured in the March 2005 issue of the American Heart Journal. TREAT is the first randomized controlled trial specifically designed to determine whether treating anemia reduces cardiovascular events in individuals with chronic kidney disease (CKD) and Type 2 diabetes.

"Existing data suggest that anemia increases the risk of cardiovascular events in patients with chronic kidney disease and Type 2 diabetes," said TREAT lead investigator, Marc Pfeffer, M.D., Ph.D., Interim Chief of Medicine at Brigham and Women´s Hospital and Professor at Harvard Medical School. "The inclusion of the TREAT rationale and methodology in the American Heart Journal highlights the cardiology community´s recognition of the need to further understand and study the link between chronic kidney disease, diabetes, anemia and cardiovascular disease."

According to the American Heart Association, people with CKD, even those in the early stages of the disorder, are in the highest-risk group for cardiovascular disease. Recent data show that the majority of CKD patients die before they ever reach dialysis. The increased cardiovascular risk found in patients with CKD is attributable to several risk factors, including anemia. Anemia is a common complication of CKD that worsens as kidney function declines.

The American Heart Journal article reviews the role of diabetes and anemia in cardiovascular disease among patients with CKD and provides the rationale for designing and conducting TREAT, which is an international 4,000 patient, multicenter, randomized, double-blind, placebo-controlled trial. Additionally, the article explains the primary endpoint of TREAT to be a composite index of time to mortality or non-fatal cardiovascular events, including myocardial infarction, myocardial ischemia, stroke and heart failure.

"We are committed to serving patients as they manage these chronic diseases and are excited to bring such an important clinical trial to the medical community," said Willard Dere, senior vice president and chief medical officer at Amgen. "TREAT is designed to definitively determine whether treating anemia reduces cardiovascular events in patients with chronic kidney disease and Type 2 diabetes."

Aranesp(R) (darbepoetin alfa) has been shown to be effective in correcting anemia with less frequent dosing than other treatments. In the U.S., Aranesp is approved to be administered once a week if a patient received Epoetin alfa two to three times weekly. The European Committee for Medicinal Products for Human Use (CHMP) approved once a month dosing in August 2004. Patients participating in TREAT will receive Aranesp once monthly. Aranesp should be administered once every two weeks if a patient received Epoetin alfa once per week.

There are TREAT study sites planned across the globe. Patients and physicians can access www.amgentrials.com for more information about TREAT.

About Aranesp(R) (darbepoetin alfa)

Aranesp is a recombinant erythropoietic protein (a protein that stimulates production of oxygen-carrying red blood cells). Amgen revolutionized anemia treatment with the development of recombinant erythropoietin, epoetin alfa, which is currently marketed in the U.S. by Amgen as EPOGEN(R) (Epoetin alfa)(i) and by Ortho Biotech Products, LP, as Procrit(R) (Epoetin alfa)(ii). Building on this heritage, Amgen developed Aranesp, which contains two additional sialic acid-containing carbohydrate chains than the Epoetin alfa molecule, resulting in more activity, with the added benefit of less-frequent administration.

Aranesp was approved by the U.S. Food and Drug Administration (FDA) in September 2001 for the treatment of anemia associated with chronic renal failure, also known as CKD, for patients on dialysis and patients not on dialysis. In July 2002, Aranesp was approved by the FDA for the treatment of chemotherapy-induced anemia in patients with nonmyeloid malignancies.

Aranesp is contraindicated in patients with uncontrolled hypertension and patients with known hypersensitivity to the active substance or any of the excipients. Erythropoietic therapies may increase the risk of thrombotic and other serious events; dose reductions are recommended if the hemoglobin increase exceeds 1.0 g/dL in any two-week period. The most commonly reported side effects in Aranesp trials were fatigue, edema, nausea, vomiting, diarrhea, fever and dyspnea.

The Aranesp dosage should be adjusted for each patient to achieve and maintain a target hemoglobin not to exceed 12 g/dL. Doses must be individualized to ensure that hemoglobin is maintained at an appropriate level for each patient.

About Amgen

Amgen is a global biotechnology company that discovers, develops, manufactures and markets important human therapeutics based on advances in cellular and molecular biology.

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Full prescribing information for Aranesp(R) is available at www.aranesp.com.

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(i) EPOGEN(R) is a registered trademark of Amgen, Inc.

(ii) PROCRIT(R) is a registered trademark of Ortho Biotech Products, L.P.

CONTACT: Amgen, Thousand Oaks Keith Givens, 805-447-4587 (media) Laura Biswas, 805-447-1060 (investors) SOURCE: Amgen