Amgen Announces Results Of Phase 3 Study Of Enbrel Dosed Once Weekly

FOR IMMEDIATE RELEASE

THOUSAND OAKS, Calif., December 5, 2002 – Amgen (NASDAQ: AMGN) today announced that a clinical study assessing 50 mg of ENBRELâ (etanercept) administered once weekly demonstrated similar efficacy, tolerability and pharmacokinetics to that of 25 mg of ENBREL administered twice weekly. “We are pleased with these results and look forward to presenting comprehensive results from this study at a future scientific meeting,” said Dr. Daniel Burge, Amgen's vice president of clinical research. “This study suggests that physicians may have the opportunity to combine the benefits and proven long-term tolerability profile of ENBREL with the flexibility of either once weekly or twice weekly dosing,” said Kevin Young, vice president and general manager of Amgen's Inflammation Business Unit.

ABOUT ENBREL
ENBREL is the only fully human anti-TNF therapy approved for use to reduce the signs and symptoms of active arthritis in patients with psoriatic arthritis, and to reduce the signs and symptoms and inhibit the structural damage in patients with moderately to severely active rheumatoid arthritis (RA). ENBREL is the only biologic therapy approved to treat newly diagnosed RA patients, and can be used alone.

Rheumatologists have become familiar with the benefits and proven long-term tolerability profile of ENBREL, having treated over 129,000 patients in over four years of post-marketing experience. ENBREL acts by binding TNF, one of the dominant inflammatory cytokines or regulatory proteins that play an important role in both normal immune function and the cascade of reactions that causes the inflammatory process of psoriatic arthritis and RA. The binding of ENBREL to TNF renders the bound TNF biologically inactive, resulting in significant reduction in inflammatory activity.

Important Treatment Considerations
SINCE THE PRODUCT WAS FIRST INTRODUCED, SERIOUS INFECTIONS, SOME INVOLVING DEATH, HAVE BEEN REPORTED IN PATIENTS USING ENBREL. MANY OF THESE INFECTIONS OCCURRED IN PATIENTS WHO WERE PRONE TO INFECTIONS, SUCH AS THOSE WITH ADVANCED OR POORLY CONTROLLED DIABETES. RARE CASES OF TUBERCULOSIS HAVE ALSO BEEN REPORTED. ENBREL SHOULD BE DISCONTINUED IN PATIENTS WITH SERIOUS INFECTIONS. DO NOT START ENBREL IF YOU HAVE AN INFECTION OF ANY TYPE OR IF YOU HAVE AN ALLERGY TO ENBREL OR ITS COMPONENTS. ENBREL SHOULD BE USED WITH CAUTION IN PATIENTS PRONE TO INFECTION. CONTACT YOUR PHYSICIAN IF YOU HAVE ANY QUESTIONS

ABOUT ENBREL OR INFECTIONS.
There have been reports of serious nervous system disorders such as multiple sclerosis, seizures, or inflammation of the nerves of the eyes. Tell your doctor if you have ever had any of these disorders or if you develop them after starting ENBRELâ (etanercept). There have also been rare reports of serious blood disorders, some involving death. Contact your doctor immediately if you develop symptoms such as persistent fever, bruising, bleeding, or paleness. It is unclear if ENBREL has caused these nervous system or blood disorders. If your doctor confirms serious blood problems, you may need to stop using ENBREL. The most frequent adverse events in placebo-controlled RA clinical trials involving 349 adults were injection site reactions (ISR) (37%), infections (35%), and headache (17%). Only the rate of ISR was higher than that of placebo. The most frequent adverse events in a methotrexate-controlled clinical trial of 415 adults with early-stage RA were infections (64%), ISR (34%), and headache (24%). Of these, only the rate of ISR was higher than that of methotrexate. Patients have been observed in clinical trials for over 3 years. The incidence of malignancies has not increased with extended exposure to ENBREL and is similar to the projected background rate. Adverse events in the psoriatic arthritis trial were similar to those reported in RA clinical trials.

Please see full Product Information.
Amgen and Wyeth Pharmaceuticals, a division of Wyeth (NYSE: WYE), market ENBREL in North America. Other Wyeth affiliates market ENBREL outside of North America. Immunex Corporation, a wholly owned subsidiary of Amgen, manufactures ENBREL. Additional information about ENBREL, including full Prescribing Information, can be found on the Web site sponsored by the companies at www.enbrel.com or by calling toll free 888-4ENBREL (888-436- 2735).

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

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 December 5, 2002, and expressly disclaims any duty to update information contained in this press release.

CONTACT: Amgen
Rebecca Hamm (media)
805/447-3872
Cary Rosansky (investors)
805/447-4634

EDITOR'S NOTE: An electronic version of this news release may be accessed via www.amgen.com. Visit the Corporate Center and click on Amgen News. Journalists and media representatives may sign up to receive all news releases electronically at time of announcement by filling out a short form.