Press Release Details

Dosing Schedule Enabled Physicians to Better Coordinate
Chemotherapy And Anemia Treatment
NEW ORLEANS----June 8, 2004-- Amgen Inc. (Nasdaq:AMGN), the world's largest biotechnology company, announced results of a new study demonstrating that Aranesp(R) (darbepoetin alfa) dosed once every three weeks achieved and maintained the target hemoglobin levels recommended by clinical guidelines. Most patients who received Aranesp during the study achieved therapeutic goals regardless of early or late treatment. The results were presented by the study's investigator, Glen Justice, M.D., Pacific Coast Hematology Oncology Medical, Fountain Valley, Calif., at the 40th Annual American Society of Clinical Oncology (ASCO) meeting. (Abstract #8064)

"These data demonstrate that Aranesp corrected anemia when administered once every three weeks, which can simplify the treatment of anemia and provide added benefit to patients and physicians by fitting easily into the existing chemotherapy schedule," said Dr. Justice. "Most patients can benefit with less frequent dosing which results in less time spent receiving anemia treatment in the doctor's office."

The analysis includes data from a randomized, open-label multi-center study of 204 patients with chemotherapy-induced anemia. Patients were randomized into two groups: baseline hemoglobin of greater than or equal to 10.5 g/dL (early intervention) and less than or equal to 12 g/dL (observation/late intervention). The early intervention group received Aranesp every three weeks from the start of the treatment period. Patients in the observation group were not treated with Aranesp unless their hemoglobin levels dropped below 10 g/dL.

Results of this study indicate that patients with chemotherapy-induced anemia who received Aranesp 300 mcg every three weeks were able to maintain optimal hemoglobin levels between 11 and 13 g/dL (in accordance with ASH/ASCO and National Comprehensive Cancer Network (NCCN) guidelines) after early intervention as well as correct anemia in patients with hemoglobin levels below 10 g/dL. Approximately 97 percent of patients in the early intervention group attained the target hemoglobin range. After late treatment with Aranesp, mean hemoglobin improved in most patients, with 90 percent of patients achieving hemoglobin values within the target range. Greater than 90 percent of both early and late intervention patients achieve the target hemoglobin of greater than or equal to 11 g/dL with mean hemoglobin near 12 g/dL for the remainder of the study.

Two national evidence-based guidelines recommend the initiation of erythropoietic therapy at different hemoglobin levels - at greater than 10 per ASH/ASCO guidelines and at greater than 11 for NCCN guidelines; maintenance of hemoglobin near 12 g/dL during anemia therapy is recommended by ASH/ASCO guidelines and NCCN guidelines.

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 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. Aranesp was approved by the FDA 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)(1) and by Ortho Biotech Products, LP, as Procrit(R)(2). Building on this heritage, Amgen developed Aranesp(R), 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.

No forward-looking statement can be guaranteed and actual results may differ materially from those we project. The Company's results may be affected by our ability to successfully market both new and existing products domestically and internationally, sales growth of recently launched products, difficulties or delays in manufacturing our products, and regulatory developments (domestic or foreign) involving current and future products and manufacturing facilities. In addition, sales of our products are affected by reimbursement policies imposed by first party payors, including governments, private insurance plans and managed care providers, and may be affected by domestic and international trends toward managed care and healthcare cost containment as well as possible US legislation affecting pharmaceutical pricing and reimbursement. Government regulations and reimbursement policies may affect the development, usage and pricing of our products. Furthermore, our research, testing, pricing, marketing and other operations are subject to extensive regulation by domestic and foreign government regulatory authorities. We, or others could identify side effects or manufacturing problems with our products after they are on the market. In addition, we compete with other companies with respect to some of our marketed products as well as for the discovery and development of new products. Discovery or identification of new product candidates cannot be guaranteed and movement from concept to product is uncertain; consequently, there can be no guarantee that any particular product candidate will be successful and become a commercial product. In addition, while we routinely obtain patents for our products and technology, the protection offered by our patents and patent applications may be challenged, invalidated or circumvented by our competitors. Further, some raw materials, medical devices, and component parts for our products are supplied by sole first party suppliers.

Aranesp prescribing information can be accessed by calling 800-772-6436 or by logging onto www.aranesp.com.

EDITOR'S NOTE: An electronic version of this news release may be accessed via our Web site at www.amgen.com. Journalists and media representatives may sign up to receive all news releases electronically at time of announcement by filling out a short form in the Media section of the Web site.

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

(2) Procrit(R) is a registered trademark of Ortho Biotech Products, L.P.

CONTACT: Amgen, Thousand Oaks, Calif.
Kelly Stoddard, (805) 447-4587 (media)
Investor Relations, (805) 447-1060 (investors)