Following Complete Review of Phase 2 Trial Data Amgen Confirms Decision to Halt GDNF Study; Comprehensive Review of Scientific Findings, Patient Safety, Drove Decision| Amgen

Following Complete Review of Phase 2 Trial Data Amgen Confirms Decision to Halt GDNF Study; Comprehensive Review of Scientific Findings, Patient Safety, Drove Decision

Company Confirms Commitment to Parkinson's Disease Research

THOUSAND OAKS, Calif., Feb 11, 2005 (BUSINESS WIRE) -- Citing patient safety concerns and scientific findings, Amgen Inc. (Nasdaq:AMGN) announced today that it has confirmed its previous decision to halt clinical trials of the experimental drug GDNF (Glial-cell-lined-derived neurotrophic factor). Amgen halted studies of GDNF when scientific results indicated that allowing patients to continue treatment could potentially cause permanent harm, complicating an already devastating disease.

As part of that decision, and based on thorough scientific review, Amgen has also concluded that it will not provide GDNF to the 48 patients who participated in clinical trials that were terminated in the fall of 2004.

"We've looked at this decision from every perspective -- scientific, medical and ethical. Our hearts truly go out to trial patients and their families, but we simply cannot allow trials to continue given the potential safety risks and the absence of proven benefit. Encouraging patients to continue in the GDNF study deters them from pursuing potentially helpful Parkinson's disease therapies that are already approved and available," said Kevin Sharer, Amgen's chairman and chief executive officer. "Our desire is to actively pursue GDNF in a meaningful way that may benefit all Parkinson's disease patients."

"We are deeply disappointed in the outcome of the trial and have enormous respect for the trial patients who struggle courageously to deal with the terrible effects of the disease," stated Roger M. Perlmutter, executive vice president, Research and Development, Amgen. "After careful review, we stand behind our decision to stop providing GDNF to patients due to potential safety risks observed in preclinical studies, including irreversible brain damage, and the absence of any demonstrated medical benefit. We adhered to the same high standards of practice we apply to all our clinical trials in making this decision."

"A team of Amgen researchers, clinicians and executives spent several months reviewing the company's initial decision to halt GDNF clinical trials. After exhaustive deliberation and input from trial investigators, patients, the FDA and consulting experts and ethicists we confirmed our decision to halt the GDNF study," added Sharer.

Amgen has actively studied Parkinson's disease therapies for more than a decade and will continue to support GDNF and the Parkinson's disease community by continuing to conduct additional research to better understand the potential of GDNF in the treatment of this terrible disease.

Discussions have been initiated with patient advocacy groups and research funding agencies to make Amgen's GDNF and other proprietary GDNF-related materials available to qualified pre-clinical researchers. Additionally, Amgen will pursue publication of both the Phase 2 study and toxicology data to further scientific understanding. Amgen will also expand the toxicology studies and work on discoveries to improve delivery of the drug.

About Amgen

Amgen is a global biotechnology company that discovers, develops, manufactures and markets important human therapeutics based on advances in cellular and molecular biology.

SOURCE: Amgen Inc.

Amgen, Thousand Oaks
Andrea Rothschild, 805-447-4587 (media)
Arvind Sood, 805-447-1060 (investors)