Amgen Announces Its Registration Statement on Form S-3 Has Been Declared Effective

THOUSAND OAKS, Calif - May 31, 2002 - Amgen Inc. (Nasdaq:AMGN) announced today that a Registration Statement on Form S-3 relating to the resale by the holders of Amgen's Liquid Yield Option Notes due 2032 (the "LYONs") and shares of Amgen common stock issuable upon conversion and/or redemption of the LYONs has been declared effective by the Securities and Exchange Commission. Amgen's issuance of the LYONs, which raised approximately $2.8 billion in gross proceeds, was completed on March 1, 2002.

This press release shall not constitute either an offer to sell or the solicitation of an offer to buy, nor shall there be any sale of these securities in any state in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state.

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 May 31, 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
Jeff Richardson, 805/447-3227 (media)
Cary Rosansky, 805/447-4634 (investors)