FDA APPROVES ENBREL AS FIRST THERAPY TO INHIBIT BONE AND JOINT DAMAGE IN PSORIATIC ARTHRITIS PATIENTS

THOUSAND OAKS, Calif., and COLLEGEVILLE, Pa., August 25, 2003 – The U.S. Food and Drug Administration (FDA) has approved an expanded indication for ENBREL (etanercept) to inhibit the progression of structural damage of active arthritis in patients with psoriatic arthritis. The approval is being announced today by Amgen (NASDAQ: AMGN) and Wyeth Pharmaceuticals, a division of Wyeth (NYSE: WYE).

ENBREL is the first and only approved therapy for both the inhibition of structural damage and the reduction in signs and symptoms of patients with psoriatic arthritis.

“This is the first time a large clinical trial has demonstrated inhibition of radiographic progression of joint damage in people with psoriatic arthritis,” says Willard Dere, M.D., Vice President of Clinical Development for Amgen. “These data underscore the benefits of treating psoriatic arthritis patients with ENBREL.”

Approval was based on a phase 3 study evaluating 205 patients with active psoriatic arthritis. ENBREL demonstrated inhibition of joint damage over a one-year study period, while x-rays of patients receiving a placebo showed progressive joint destruction.

"ENBREL has now been shown to inhibit underlying joint damage in two distinct diseases, rheumatoid arthritis, and now, psoriatic arthritis", says Victoria Kusiak, M.D., Vice President of Global Medical Affairs and North American Medical Director of Wyeth Pharmaceuticals. “As with rheumatoid arthritis, treatment with ENBREL can improve the painful and debilitating symptoms of psoriatic arthritis. ”

Adverse events were similar to those reported in previous clinical trials of ENBREL in patients with rheumatoid arthritis. There was no increase in the number of serious adverse events occurring in patients treated with ENBREL compared to those receiving placebo. Only the rate of injection site reactions (ISRs) in patients receiving ENBREL was statistically different compared to those receiving placebo (36 percent with ENBREL versus 9 percent in placebo-treated patients).

ABOUT PSORIATIC ARTHRITIS

Psoriatic arthritis is a chronic inflammatory disease of the joints and connective tissue. The disease combines joint pain and swelling that can lead to crippling debilitation with inflamed and irritated scaly red patches of skin on the body. The disease can be difficult to diagnose, particularly in its milder forms and earlier stages. Up to one million people in the U.S. population have psoriatic arthritis.

ABOUT ENBREL

ENBREL is the only fully human anti-TNF receptor approved to reduce signs and symptoms, improve physical function, and inhibit structural damage in patients with moderately to severely active rheumatoid arthritis (RA), and to reduce the signs and symptoms and inhibit the progression of structural damage in patients with active psoriatic arthritis. ENBREL is the only biologic therapy approved for first-line treatment of RA patients, and can be used in combination with methotrexate or alone. It is 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. It is also the first biologic approved to treat the signs and symptoms in patients with active ankylosing spondylitis (AS).

The benefits and long-term tolerability profile of ENBREL have been established in the treatment of over 180,000 patients worldwide across all indications.

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, RA and AS. The binding of ENBREL to TNF renders the bound TNF biologically inactive, resulting in significant reduction in inflammatory activity.

Since the product was first introduced, the following have been reported in patients using ENBREL: • Serious Infections

• What to do / Not do

• Serious nervous system disorders such as multiple sclerosis, seizures, or inflammation of the nerves of the eyes.

• Rare reports of serious blood disorders (some fatal) • The incidence of cancer has not increased with extended exposure to ENBREL and is similar to the expected rate.

• ENBREL can also cause injection site reactions.

• In a medical study of patients with JRA, infections, headaches, abdominal pain, vomiting, and nausea occurred more frequently than in adults.

Amgen and Wyeth Pharmaceuticals, a division of Wyeth, market ENBREL in North America. Wyeth markets 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 others that can be found in Amgen's Form 10-K for the year ended December 31, 2002, and in Amgen's 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. Amgen's results may be affected by its ability to successfully market both new and existing products domestically and internationally, sales growth of recently launched products, difficulties or delays in manufacturing its products, and regulatory developments (domestic or foreign) involving current and future products and manufacturing facilities.

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, and may be affected by domestic and international trends toward managed care and healthcare cost containment as well as possible U.S. legislation affecting pharmaceutical pricing and reimbursement. Government regulations and reimbursement policies may affect the development, usage and pricing of Amgen's products. Furthermore, Amgen's research, testing, pricing, marketing and other operations are subject to extensive regulation by domestic and foreign government regulatory authorities. Amgen or others could identify side effects or manufacturing problems with its products after they are on the market. In addition, Amgen competes with other companies with respect to some of its 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 Amgen routinely obtains patents for its products and technology, the protection offered by its patents and patent applications may be challenged, invalidated or circumvented by its competitors. Further, some raw materials, medical devices and component parts for Amgen's products are supplied by sole third party suppliers. The statements in this press release that are not historical facts are forward-looking statements based on current expectations of future events that involve risks and uncertainties including, without limitation, risks associated with the inherent uncertainty of pharmaceutical research, product development, manufacturing, and commercialization, and economic conditions, including interest and currency exchange rate fluctuations, the impact of competitive or generic products, product liability and other types of lawsuits, the impact of legislative and regulatory compliance and obtaining approvals, and patents, and other risks and uncertainties, including those detailed from time to time in Wyeth's periodic reports, including quarterly reports on Form 10-Q and the Annual Report on Form 10-K, filed with the Securities and Exchange Commission. Actual results may vary materially from the forward-looking statements.

Wyeth assumes no obligation to publicly update any forward-looking statements, whether as a result of new information, future events or otherwise.

For further information please contact::
Media : 805-4474587 Wyeth Pharmaceuticals Investors: 805-447-1060 Douglas Petkus (media) 484-865-5140 Justin
Victoria (investors) 973-660-5340