Amgen Continues Manufacturing Expansion with Additional $1 Billion Investment in Puerto Rico.

THOUSAND OAKS, Calif. -- Amgen (Nasdaq:AMGN), the world's largest biotechnology company, today announced that it expects to invest $1 billion over the next four years to expand its manufacturing capacity in Puerto Rico to meet rising global demand for the company's products.

Fabrizio Bonanni, senior vice president, Manufacturing, said the investment will include expansion of existing facilities in the company's manufacturing complex in Juncos, Puerto Rico, and the construction of a new formulation, fill and finish facility. Amgen expects to add approximately 500 staff members in Puerto Rico by 2010.

"By significantly increasing capacity in Puerto Rico and elsewhere around the world, Amgen enhances its ability to supply every patient, every time, with our vital medicines," said Bonanni. "We also position ourselves to deliver on Amgen's rich and diverse pipeline."

Bonanni said Puerto Rico's attractive business climate and strong commitment to developing biotechnology manufacturing capability, as demonstrated by the formation of the Puerto Rico Science and Technology Trust and establishment of biotechnology manufacturing programs at University of Puerto Rico Mayaguez and elsewhere, were key factors in the decision to expand operations there.

In Puerto Rico Amgen expects to enlarge its NEUPOGEN(R) (Filgrastim) and Neulasta(R) (pegfilgrastim) bulk protein manufacturing facility, licensed in 2005, as well as the newly built EPOGEN(R) (Epoetin alfa) and Aranesp(R) (darbepoetin alfa) bulk plant. In addition, the company anticipates construction of a new formulation, fill and finish facility as well as upgrades to its existing formulation, fill and finish operations.

Since Amgen's founding in 1980, Amgen has been a pioneer in biologics manufacturing, developing some of the first and most successful processes for large-scale protein production. Over the last five years, Amgen has invested more than $3 billion to enhance its manufacturing capabilities in the United States and has added more than 4,000 operations jobs in the U.S. since 2001.

In 2005 Amgen opened an Enbrel(R) (etanercept) plant in Rhode Island, and announced plans to acquire Abgenix, Inc., a leading biopharmaceutical company with a large manufacturing plant in Fremont, California.

Last week Amgen announced plans to invest approximately $1 billion in new bulk protein manufacturing and formulation, fill and finish facilities in Cork, Ireland, that will give the company capacity closer to the patients it serves in Europe. Amgen also announced that it intends to expand its existing research and development operations in Cambridge, Mass., South San Francisco, Seattle, and Cambridge, U.K., and build a new development center in Uxbridge, U.K.

Amgen's growth in research and development marks a unique transformation in the company's history. As others in the industry consolidate and reduce workforces, Amgen is launching a major global expansion of its R&D efforts in a number of scientific hubs throughout the world.

"This significant, long-term investment in our global R&D infrastructure underscores the commitment of Amgen to be the world's best human therapeutics company," said Roger M. Perlmutter, executive vice president, Research and Development. "In particular, our growth in clinical development in South San Francisco and Uxbridge, U.K. will provide the capability to deliver on the promise of our extraordinary pipeline."

About Amgen

Amgen discovers, develops and delivers innovative human therapeutics. A biotechnology pioneer since 1980, Amgen was one of the first companies to realize the new science's promise by bringing safe and effective medicines from lab, to manufacturing plant, to patient. Amgen therapeutics have changed the practice of medicine, helping millions of people around the world in the fight against cancer, kidney disease, rheumatoid arthritis, and other serious illnesses. With a broad and deep pipeline of potential new medicines, Amgen remains committed to advancing science to dramatically improve people's lives. To learn more about our pioneering science and our vital medicines, visit www.amgen.com.

Forward-Looking Statements

This news release contains forward-looking statements that involve significant risks and uncertainties, including those discussed below and others that can be found in our Form 10-K for the year ended December 31, 2004, and in our 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. The company's results may be affected by our ability to successfully market both new and existing products domestically and internationally, sales growth of recently launched products, difficulties or delays in manufacturing our products, and regulatory developments (domestic or foreign) involving current and future products and manufacturing facilities. In addition, sales of our products are affected by reimbursement policies imposed by first 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 our products. Furthermore, our research, testing, pricing, marketing and other operations are subject to extensive regulation by domestic and foreign government regulatory authorities. We, or others, could identify side effects or manufacturing problems with our products after they are on the market. In addition, we compete with other companies with respect to some of our 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 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. Further, some raw materials, medical devices, and component parts for our product are supplied by sole third party suppliers.

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