AMGEN ANNOUNCES POSITIVE STUDY RESULTS OF KINERET(R) IN RHEUMATOID ARTHRITIS DISEASE PROGRESSION AND IN THE TREATMENT OF JUVENILE RHEUMATOID ARTHRITIS

Late Breaking Poster and Press Conference Featuring New Kineret Data Scheduled at 66th American College of Rheumatology Annual Scientific Meeting


FOR IMMEDIATE RELEASE

THOUSAND OAKS, Calif., October 25, 2002 -- Amgen (NASDAQ:AMGN) today announced results from the largest study to date exploring a biologic therapy's impact on disease progression in rheumatoid arthritis (RA). Data from a study evaluating the ability of Kineret® (anakinra) to inhibit bone and joint damage in adult RA patients will be presented at a late-breaking poster session. In addition, interim results from an efficacy and tolerability study of Kineret in patients with juvenile rheumatoid arthritis (JRA) will be featured tomorrow at a press conference at the 66th American College of Rheumatology Annual Scientific Meeting in New Orleans.

"The results seen with Kineret are exciting because they signal that we may have another therapeutic option for slowing the progression of RA," said Dr. William Shergy, a rheumatologist at Rheumatology Associates of North Alabama. "This disease involves a silent destruction of bones and joints which, if left untreated, leads to deformity and disability."

Bone and Joint Inhibition

In a 12 month, double-blind study of 906 adult RA patients, Kineret-treated patients experienced less bone and joint destruction as measured by total modified Sharp score than patients treated with placebo plus methotrexate. The mean change in Sharp score was 36 percent lower for Kineret than placebo at week 52 of the study (p<0.001). The effect of Kineret was evident early, with significant inhibition of disease progression by week 24. At week 52, 50 percent Kineret patients had no disease progression compared with 42 percent of placebo patients (p=0.018), and fewer Kineret patients had severe disease progression than placebo patients (12 percent vs. 19 percent, p=0.003). A reduction in progression was seen in joint erosion and joint space narrowing, two important measures of the debilitating impact of RA. Kineret® was well tolerated in this study. The incidence of overall adverse events, serious adverse events, events leading to withdrawal, and infectious events were similar in the Kineret and placebo groups. No opportunistic infections or cases of tuberculosis were reported. The most common adverse events were injection site reactions, which generally were mild and did not result in patient withdrawal from the study.

On October 22, Amgen announced that it had submitted a supplemental Biologics License Application with the U.S. Food and Drug Administration for the use of Kineret to inhibit the progression of structural damage in adult RA patients.

Juvenile Rheumatoid Arthritis

A 16-week multi-center, blinded, placebo-controlled study of 76 pediatric JRA patients (aged 2 years -17 years) included a 12-week open-label "run-in" period in which all patients were treated with Kineret (1 mg/kg daily subcutaneous injections). The results after 12 weeks show that 64 percent of the patients who reached week 12 and were assessed for efficacy (n=56) exhibited at least a 30 percent improvement in their disease based on the JRA Core Set Criteria when compared to baseline, and were considered responders. The JRA Core Set Criteria include number of active joints, number of joints with limited motion, physician's global assessment, patient's/parent's global assessment, children's Health Assessment Questionnaire, and a lab test known as erythrocyte sedimentation rate.

Kineret was well tolerated over the study period and presents a safety profile that is comparable with prior studies of Kineret in adult patients. The most common adverse events observed were injection site reactions. No tuberculosis or other serious opportunistic infections, malignancies or deaths were reported.

Results from this study require confirmation in larger studies to determine the safety and efficacy of Kineret in JRA patients.

About Kineret

Kineret is the only approved therapy that directly and selectively blocks interleukin-1 (IL-1), a protein present in excess in RA patients. By blocking IL-1, Kineret inhibits the inflammatory response in RA including pain.

Kineret is part of Amgen's portfolio of therapies to treat RA.

Kineret is indicated for the reduction in signs and symptoms of moderately to severely active RA in adult patients who have failed one or more disease modifying anti-rheumatic drugs. It can be used alone or in combination with DMARDs, other than Tumor Necrosis Factor (TNF) blocking agents.

The most common side effect seen with Kineret in clinical trials was a reaction at the site of injection, usually mild, characterized by redness, swelling and pain. Also, there was a risk of serious infections (2 percent in Kineret patients vs. less than 1 percent in placebo patients). Although Kineret should be discontinued if a patient develops an infection, most patients can continue taking Kineret after their infection resolves. Kineret should not be used with TNF blocking agents etanercept and infliximab. A 7 percent rate of serious infections was observed in two studies with concurrent administration of Kineret and etanercept.

This news release contains forward-looking statements that involve significant risks and uncertainties, including those discussed below and more fully described in the Securities and Exchange Commission reports filed by Amgen, including our most recent Form 10-Q. Amgen conducts research in the biotechnology/pharmaceutical field where 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.

Furthermore, our research, testing, pricing, marketing and other operations are subject to extensive regulation by domestic and foreign government regulatory authorities. In addition, sales of our products are affected by reimbursement policies imposed by third party payors, including governments, private insurance plans and managed care providers. These government regulations and reimbursement policies may affect the development, usage and pricing of our products.

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.

Because forward-looking statements involve risks and uncertainties, actual results may differ materially from current results expected by Amgen. Amgen is providing this information as of October 25, 2002, and expressly disclaims any duty to update information contained in this press release.

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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Contact: Amgen, Thousand Oaks
Rebecca Hamm, 805/447-3875 (media)
Cary Rosansky, 805/447-4634 (investors)


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