FDA Approves Enbrel Manufacturing Facility; Supply For Patients Dramatically Increases

THOUSAND OAKS, Calif., and RADNOR, Pa., Dec. 23, 2002 - Amgen (NASDAQ: AMGN) and Wyeth Pharmaceuticals, a division of Wyeth (NYSE: WYE), today announced that the U.S. Food and Drug Administration (FDA) has approved Amgen's Rhode Island manufacturing facility for ENBREL (etanercept). With this approval, significant supply of ENBREL is now available for patients since production has been underway at the facility for many months. Over one million patients with rheumatoid arthritis, juvenile rheumatoid arthritis and psoriatic arthritis in the United States are potential candidates for this breakthrough biologic.

"Working in close harmony with the FDA, we are delighted to beat our expected timelines and make ENBREL available to patients as quickly as possible," said Kevin Sharer, Amgen's Chairman and CEO. "The facility is among the most advanced cell culture manufacturing centers in the world and is expected to more than satisfy the expanding patient demand for this unique therapy."

"We believe this news, combined with five years of outstanding clinical performance and tolerability, will encourage physicians to once again make ENBREL their first choice for patients," said Joseph Mahady, president, North America, Wyeth Pharmaceuticals.

"ENBREL is a very important treatment option," said Dr. Larry Moreland, professor of medicine, University of Alabama at Birmingham and one of the original investigators for this breakthrough product. "It is the biologic with the most extensive clinical data in treating rheumatic diseases, leading to the broadest range of indications. This is extremely welcome news for physicians who recognize that there are more patients who can benefit from ENBREL."

"ENBREL has helped me do the activities I used to do before I had rheumatoid arthritis," said eighth-grade science teacher Hepsi Zsoldos, an ENBREL patient since 2001. "It has helped me live my life to the fullest, including recently teaching aboard a 24-day deep-sea oceanographic research expedition in the Pacific Ocean. I am able to do more than I ever thought I could."

ABOUT THE FACILITY

The 250,000 square foot structure houses eight 8,000-liter bioreactors, the tightly controlled vessels needed to produce large quantities of ENBREL through recombinant DNA technology. More than 550 highly skilled professionals monitor the ENBREL being produced, and perform hundreds of routine controls and validation studies throughout the manufacturing process to help ensure its quality.

"We are proud of our strong heritage in biotechnology manufacturing, and honored to contribute to the well-being of so many patients by making ENBREL available to all who need it," said Fabrizio Bonanni, senior vice president of quality and compliance. "It has taken a tremendous effort by hundreds of people to complete Amgen's largest-ever manufacturing facility in record time."

ABOUT ENBREL

ENBREL is the only fully human anti-TNF receptor 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. It is also approved to reduce the signs and symptoms of moderately to severely active polyarticular-course juvenile rheumatoid arthritis (JRA) in patients who have had an inadequate response to disease-modifying medicines.

Physicians have become familiar with the benefits and proven long-term tolerability profile of ENBREL. It has been used to treat over 130,000 patients worldwide since becoming commercially available four years ago, making it one of the fastest-growing prescription products ever launched.

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 ENBREL. 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.

In a study of 69 patients with JRA, infections (62%), headache (19%), abdominal pain (19%), vomiting (13%), and nausea (9%) occurred more frequently than in adults. The types of infections reported in JRA patients were generally mild and consistent with those commonly seen in children. Serious adverse reactions reported rarely were chicken pox (3%), gastroenteritis (3%), serious infection (2%), depression/personality disorder (1%), skin ulcer (1%), inflammation in parts of the upper digestive tract (1%), and diabetes (1%).

Amgen and Wyeth Pharmaceuticals, a division of Wyeth, 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.

Wyeth Pharmaceuticals, a division of Wyeth, has leading products in the areas of women's health care, cardiovascular disease, central nervous system, inflammation, hemophilia, oncology and vaccines. Wyeth is one of the world's largest research-driven pharmaceutical and health care products companies. It is a leader in the discovery, development, manufacturing, and marketing of pharmaceuticals, vaccines, biotechnology products and non-prescription medicines that improve the quality of life for people worldwide. The Company's major divisions include Wyeth Pharmaceuticals, Wyeth Consumer Healthcare and Fort Dodge Animal Health.

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, Amgen's research, testing, pricing, marketing and other operations are subject to extensive regulation by domestic and foreign government regulatory authorities. In addition, sales of Amgen's 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 products.

In addition, while Amgen routinely obtains patents for its products and technology, the protection offered by patents and patent applications may be challenged, invalidated or circumvented by 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 23, 2002, and expressly disclaims any duty to update information contained in this press release.

CONTACT: Amgen
Jeff Richardson (media)
805/447-3227
Rebecca Hamm (media)
805/447-3872
Cary Rosansky (investors)
805/447-4634

Wyeth Pharmaceuticals
Douglas Petkus (media)
610/902-7336
Justin Victoria (investors)
973/660-5340

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