Abgenix and Amgen Announce FDA Grants Panitumumab Fast Track Designation for Metastatic Colorectal Cancer

THOUSAND OAKS, Calif. & FREMONT, Calif.--(BUSINESS WIRE)--Aug. 1, 2005--Amgen (Nasdaq:AMGN) and Abgenix, Inc. (Nasdaq:ABGX) today announced that the U.S. Food and Drug Administration (FDA) has granted fast track designation for panitumumab, an experimental fully human monoclonal antibody directed against the epidermal growth factor receptor (EGFr), for patients with metastatic colorectal cancer who have failed standard chemotherapy treatment.

"We are advancing the development of panitumumab with the hope of offering patients a new treatment option in their fight against metastatic colorectal cancer," said Willard Dere, M.D., chief medical officer and senior vice president of global development at Amgen.

Under the FDA Modernization Act of 1997, fast track designation allows the FDA to accept, on a rolling basis, portions of a marketing application for review prior to the completion of the final registrational package. Fast track designation may potentially expedite the review of a drug that is intended for the treatment of a serious life-threatening condition and demonstrates the potential to address an unmet medical need for such a condition.

In light of this fast track designation, Amgen and Abgenix are working toward initiating the submission of the Biologics License Application (BLA) for panitumumab in patients who have failed prior standard chemotherapy, including irinotecan and oxaliplatin, by the end of 2005. The completed submission of the BLA could extend into the first quarter of 2006, depending on timing and outcome of clinical data. FDA has previously indicated that data from one pivotal trial, once completed, could be acceptable with additional data from other pending studies to support a submission for marketing approval in the United States.

"Panitumumab is the first fully human monoclonal antibody to inhibit EGFr, and fast track designation represents an important milestone in its development," said Bill Ringo, chief executive officer at Abgenix. "We are one step closer to bringing this promising new treatment to patients with advanced colorectal cancer."

Patients and physicians can access www.amgentrials.com for more information about ongoing panitumumab clinical trials.

About Panitumumab

Co-developed by Amgen and Abgenix, panitumumab is an investigational product in a novel class of targeted cancer treatments called epidermal growth factor receptor (EGFr) inhibitors. Panitumumab (formerly ABX-EGF) is the first fully human monoclonal antibody directed against EGFr and is being evaluated as both a monotherapy and in combination with other agents for the treatment of various types of cancer, including colorectal, lung and kidney. Panitumumab was generated with Abgenix's XenoMouse(R)(1) technology, which creates a fully human monoclonal antibody that contains no murine (mouse) protein. The fully human nature of panitumumab may result in a safety profile with a low incidence of infusion reactions, antigenicity and allergic response. These are attributes currently being investigated in clinical trials. Pivotal clinical studies evaluating panitumumab as a third-line monotherapy in colorectal cancer patients are ongoing with an every-other-week dosing regimen.

About the Epidermal Growth Factor Receptor (EGFr)

Although EGFr normally helps regulate the growth of many different cells in the body, EGFr can also stimulate cancer cells to grow. In fact, many cancer cells actually require signals mediated by EGFr for their survival. Residing on the surface of these tumor cells, EGFr is activated when naturally occurring proteins in the body, epidermal growth factor (EGF) or transforming growth factor alpha (TGFa), bind to it. This binding changes the shape of EGFr, which, in turn, triggers internal cellular signals that stimulate tumor cell growth.

Panitumumab binds to EGFr, preventing EGF and TGFa from binding to the receptor and interfering with the signals that would otherwise stimulate growth of the cancer cell and allow it to survive.

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.

About Abgenix

Abgenix is a biopharmaceutical company focused on the discovery, development and manufacturing of human therapeutic antibodies. The company's antibody development platform includes a leading technology and state-of-the-art manufacturing capabilities that enable the rapid generation, selection and production of high affinity, fully human antibody product candidates to a variety of disease targets. Abgenix leverages its leadership position in human antibody technology to build a diversified product portfolio through its own development efforts and the establishment of collaborations with multiple pharmaceutical and biotechnology companies. For more information on Abgenix, visit the company's website at www.abgenix.com.

Amgen Forward-Looking Statement

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Abgenix Forward-Looking Statement

Statements made in this press release about Abgenix's technologies, product development activities and collaborative arrangements, other than statements of historical fact, are forward-looking statements and are subject to a number of uncertainties that could cause actual results to differ materially from the statements made, including risks associated with the timing and success of clinical trials, the progress of research and product development programs, product manufacturing, regulatory approval processes, competitive products and services and the extent and breadth of Abgenix's patent portfolio. Please see Abgenix's public filings with the Securities and Exchange Commission for information about risks that may affect Abgenix, including its Form 10-K for the year ended December 31, 2004, and periodic reports on Form 10-Q and Form 8-K.

(1) XenoMouse(R) is a registered trademark of Xenotech, a wholly-owned subsidiary of Abgenix, Inc.

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    SOURCE: Amgen