Head-to-Head Studies Show Aranesp Dosed Every Two Weeks is Comparable to Epoetin Alfa Dosed Once a Week

NEW ORLEANS----June 8, 2004--Amgen Inc. (Nasdaq:AMGN), the world's largest biotechnology company, today presented final results from an analysis of three identical head-to-head trials showing that Aranesp(R) (darbepoetin alfa) dosed once every two weeks provided similar results as epoetin alfa dosed once every week in boosting hemoglobin and reducing the need for blood transfusions in cancer patients with chemotherapy-induced anemia. The results were presented by the study's lead investigator, Lee Schwartzberg, M.D., medical director of The West Clinic, Memphis, Tenn., at the 40th Annual American Society of Clinical Oncology (ASCO) meeting. (Abstract #8063)

"These are the first clinical data from head-to-head comparisons that show the comparability of Aranesp dosed every two weeks versus epoetin alfa dosed once a week," said Dr. Schwartzberg. "These results are important as the data implies that less frequent dosing with Aranesp may provide increased patient convenience without compromising effectiveness."

The analysis includes data on 312 patients across the three studies with breast, non-small cell lung cancer, and gynecological cancer who were randomized to receive either Aranesp 200 mcg every two weeks or epoetin alfa 40,000 U every week. Whether treated with Aranesp or epoetin alfa, patients in this study achieved target hemoglobin of greater than or equal to 11 g/dL and had similar transfusion rates.

The results were analyzed based upon the achievement and maintenance of target hemoglobin threshold (greater than or equal to 11 g/dL) and range (11-13 g/dL, which is based on the ASH/ASCO and National Comprehensive Cancer Network (NCCN) guidelines for cancer and treatment-related anemia). Patients in both arms of the studies achieved and maintained hemoglobin levels of 11-13 g/dL. The median time to reach the target hemoglobin level was five weeks in the Aranesp group and four weeks in the epoetin alfa group. After achieving the target hemoglobin level, 81 percent of patients in the Aranesp group remained in the target range compared to 75 percent in the epoetin alfa group.

Aranesp allows patients to reach therapeutic goals while providing the convenience of less frequent dosing. Results of a patient satisfaction questionnaire given to study participants demonstrate that medical visits for anemia treatment incur a clinically meaningful burden on patients and caregivers. Patients spend on average two hours traveling to and from their oncologist's office and two hours at the office receiving treatment. In addition, the survey shows that the majority of patients would prefer to spend time with family and friends.

"These survey results reveal that cancer patients and their caregivers spend a considerable amount of time for cancer treatments resulting in more time away from family, friends and work," said Dr. Schwartzberg. "Our results imply that patients and caregivers can benefit from every two week dosing of Aranesp, which can result in less travel and less time in the physician's office. It is a win-win situation for everyone."

The number and type of adverse events were similar between the two treatment groups and were consistent with the adverse event profile for this population of anemic cancer patients receiving Aranesp.

About Aranesp

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

Aranesp is a recombinant erythropoietic protein (a protein that stimulates production of oxygen-carrying red blood cells). Amgen revolutionized anemia treatment with the discovery of recombinant erythropoietin, epoetin alfa, which is currently marketed in the U.S. by Amgen as EPOGEN(R)(i) and by Ortho Biotech Products, LP, as Procrit(R)(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 is contraindicated in patients with uncontrolled hypertension. 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.

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.

FORWARD LOOKING STATEMENT

This news release contains forward-looking statements that involve significant risks and uncertainties, including those discussed below and others that can be found in our Form 10-K for the year ended December 31, 2003, and in our periodic reports on Form 10-Q and Form 8-K. Amgen is providing this information as of the date of this news release and does not undertake any obligation to update any forward-looking statements contained in this document as a result of new information, future events or otherwise.

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Aranesp prescribing information can be accessed by calling 800-772-6436 or by logging onto 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

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