Moving molecules from laboratory to patients involves years of detailed investigation and rigorous testing. Clinical development requires enormous investments in time and resources. It begins with preclinical testing and proceeds through a series of human clinical trials that establish dosage levels, test for efficacy and side effects, and, depending on the molecule, may ultimately seek to measure long-term patient outcomes.

Preclinical studies collect data to show that a molecule is reasonably safe for use in initial small-scale clinical trials.

Phase 1 clinical trials investigate safety and proper dose ranges of a product candidate in a small number of human subjects.

Phase 2 clinical trials investigate side effect profiles and efficacy of a product candidate in a large number of patients who have the disease or condition under study.

Phase 3 clinical trials investigate the safety and efficacy of a product candidate in a large number of patients who have the disease or condition under study.

These tables are current as of February 3, 2005, and show the status of selected clinical and preclinical molecules in Amgen's product pipeline. Amgen's product pipeline will change over time as molecules move through the drug development process, including progressing to market or failing in clinical trials, due to the nature of the development process. These tables contain forward-looking statements that involve significant risks and uncertainties, including those discussed in Amgen's most recent Form 10-K and in Amgen's periodic reports on Form 10-Q and Form 8-K, and actual results may vary materially. Amgen is providing this information as of the date above and does not undertake any obligation to update any forward-looking statements contained in this table as a result of new information, future events or otherwise.

For more information on Amgen's product pipeline, please visit www.amgen.com.

For important safety information about Amgen's marketed products, please visit www.amgen.com for links to the product Web sites.