Label Also Updated with ENBREL Data Demonstrating Inhibition of Joint Destruction among Most Psoriatic Arthritis Patients Treated Continuously for Two Years

THOUSAND OAKS, Calif. & COLLEGEVILLE, Pa.--(BUSINESS WIRE)--June 1, 2005-- Amgen Inc. (NASDAQ:AMGN) and Wyeth Pharmaceuticals, a division of Wyeth (NYSE:WYE), today announced that the U.S. Food and Drug Administration (FDA) approved an expanded indication for Enbrel(R) (etanercept) to improve physical function in patients with psoriatic arthritis. ENBREL is the first and only treatment to receive this expanded indication. In addition, the FDA approved an update to the ENBREL label to include new radiographic data demonstrating that ENBREL continued to inhibit the progression of joint destruction for two years among most psoriatic arthritis patients who received ongoing therapy.

ENBREL received its approval to treat signs and symptoms of psoriatic arthritis in 2002. With this expanded approval, ENBREL is now indicated for reducing signs and symptoms, inhibiting the progression of joint destruction of active arthritis associated with psoriatic arthritis, and improving physical function in patients with psoriatic arthritis. ENBREL is also approved to treat moderate-to-severe rheumatoid arthritis and juvenile rheumatoid arthritis, ankylosing spondylitis and moderate-to-severe plaque psoriasis.

"This approval for improving physical function and the addition of the two-year radiographic data builds on the well-established efficacy and safety profile of ENBREL in psoriatic arthritis. No other treatment has been FDA-approved to provide efficacy for psoriatic arthritis patients using these multiple clinical measures," said Will Dere, M.D., chief medical officer and senior vice president of global development, Amgen. "ENBREL is unique because it has received 10 FDA approvals in five distinct diseases and has been used by more than 280,000 patients worldwide across indications. ENBREL also has 12 years of collective clinical experience."

The expanded approval of ENBREL was based on significant improvements in physical function as assessed by the disability index of the Health Assessment Questionnaire (HAQ), a test used to evaluate a patient´s ability to perform daily activities such as dressing, walking and grooming, and the Medical Outcomes Study Short-Form Health Survey (SF-36), a measurement tool that also assesses the physical impact of a disease.

Almost 40 percent of psoriatic arthritis patients taking ENBREL in this study achieved a HAQ score of zero, indicating no functional disability at 24 weeks. In addition, the SF-36 found that many patients treated with ENBREL experienced a greater improvement from baseline, compared to placebo, in their ability to participate in physical activities such as walking, carrying groceries, or climbing a flight of stairs.

Psoriatic arthritis is a chronic, often destructive disease characterized by both joint inflammation and erosion, and is associated with psoriatic skin lesions. The progressive joint pain and swelling, which is often coupled with painful, scaly, red skin lesions, can disrupt a person´s ability to perform activities of daily life that most people take for granted such as getting dressed, eating or walking. Approximately one million people suffer from psoriatic arthritis in the United States.

"We are pleased that ENBREL has shown the ability to inhibit the progression of joint destruction for a continuous two years in most psoriatic arthritis patients in this study, which is vital in helping to ease the debilitating effects of this disease," said Gary L. Stiles, M.D., executive vice president and chief medical officer of Wyeth Pharmaceuticals. "Similar to rheumatoid arthritis, ENBREL is the only treatment approved to provide long-term inhibition of joint destruction for most patients."

ABOUT ENBREL

ENBREL is the only soluble tumor necrosis factor (TNF) receptor approved to reduce signs and symptoms, induce major clinical response, improve physical function, and inhibit the progression of structural damage in patients with moderately to severely active rheumatoid arthritis (RA). ENBREL can be used alone or in combination with methotrexate.

ENBREL is the only treatment indicated to reduce the signs and symptoms, inhibit the progression of structural damage of active arthritis, and improve physical function in patients with psoriatic arthritis. It is approved to reduce the signs and symptoms of moderately to severely active polyarticular-course juvenile rheumatoid arthritis (JRA) in patients four years of age or older who have had an inadequate response to one or more disease-modifying antirheumatic drugs (DMARDs). It is also the first biologic approved to reduce the signs and symptoms in patients with active ankylosing spondylitis (AS). ENBREL is indicated for the treatment of adult patients (18 years or older) with chronic moderate-to-severe plaque psoriasis who are candidates for systemic therapy or phototherapy.

ENBREL has been used by more than 280,000 patients worldwide across 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 involved in the inflammatory process of RA, JRA, psoriasis, psoriatic arthritis, and AS. The binding of ENBREL to TNF renders the bound TNF biologically inactive, resulting in significant reduction in inflammatory activity.

What important information do I need to know about taking ENBREL?

ENBREL is a type of protein called a tumor necrosis factor (TNF) blocker that blocks the action of a substance your body´s immune system makes called TNF. People with an immune disease, such as rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis, and psoriasis, have too much TNF in their bodies. ENBREL can reduce the amount of TNF in the body to normal levels, helping to treat your disease. But, in doing so, ENBREL can also lower the ability of your immune system to fight infections.

All medicines have side effects, including ENBREL. Possible side effects of ENBREL include:

Serious infections Many occurred in people prone to infection, such as those with advanced or poorly controlled diabetes Some serious infections have been fatal Rare cases of tuberculosis have occurred What not to do Do not start ENBREL if you have an infection or are allergic to ENBREL or its components What to do Tell your doctor if you are prone to infection Stop ENBREL if a serious infection occurs Contact your doctor if you have questions about ENBREL or develop an infection Tell your doctor if you have ever been treated for heart failure 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 Rare reports of serious blood disorders (some fatal) Contact your doctor immediately if you develop symptoms such as persistent fever, bruising, bleeding, or paleness In medical studies of all TNF blockers, including ENBREL, a higher rate of lymphoma (a type of cancer) was seen compared to the general population. The risk of lymphoma may be up to several fold higher in rheumatoid arthritis and psoriasis patients The role of TNF blockers, including ENBREL, in the development of lymphoma is unknown ENBREL can cause injection site reactions.

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 website 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, transplantation, hemophilia, oncology, vaccines and nutritional products. 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 nonprescription 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.

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CONTACT: Amgen Nurha Hindi, 805-447-4587 (media) Arvind Sood, 805-447-1060 (investors) or Wyeth Pharmaceuticals Candace Steele, 484-865-5428 (media) Justin Victoria, 973-660-5340 (investors) SOURCE: Amgen