Abgenix Announces Data Presentations for Product Candidates at Upcoming Medical Meetings.

FREMONT, Calif. -- Panitumumab abstracts to be presented at EORTC-NCI-AACR Symposium and ESMO; ABX-PTH abstracts to be presented at ASBMR and ASN 

Abgenix, Inc. (Nasdaq:ABGX) today announced several abstracts regarding its clinical stage antibody product candidates will be presented at upcoming medical and scientific conferences this Fall.

Panitumumab(1)

Three abstracts summarizing preclinical findings with panitumumab, the first fully human monoclonal antibody that binds to the epidermal growth factor receptor (EGFr), will be presented at the 16th EORTC-NCI-AACR Symposium on Molecular Targets and Cancer Therapeutics in Geneva, Switzerland later this week. The following abstracts will be presented during the "Monoclonal Antibodies and Targeted Toxins/Nuclides" Poster Presentation Session on Thurs., Sept. 30:

--"Mono- and Combination-Therapeutic Activity of Panitumumab on Human A431 Epidermoid and HT-29 Colon Carcinoma Xenografts: Correlation with Pharmacodynamic Parameters."

--"Patterns of Gene Expression can Prospectively Predict Panitumumab Monotherapy Responsiveness in Xenograft Models."

--"Immunoassay and Mass Spectrometry Analysis of Specific EGFr Phospho-Tyrosines; Effects of Panitumumab, A Fully Humanized anti-EGFr Monoclonal Antibody, and the Kinase Inhibitor AG1478."

In addition, abstracts, including data from an ongoing phase 2 study of panitumumab, will be presented at the 29th European Society for Medical Oncology (ESMO) Congress in Vienna, Austria, Oct. 30 - Nov. 2, 2004:

--"Panitumumab Therapy with Irinotecan, 5-Fluorouracil, and Leucovorin (IFL) in Patients with Metastatic Colorectal Cancer," (Poster Presentation #265, Jordan Berlin, Sat., Oct. 30)

--"Pharmacokinetics (PK) of panitumumab and irinotecan were not altered after first-line panitumumab therapy with irinotecan, 5-fluorouracil, and leucovorin (IFL) in metastatic colorectal cancer (mCRC) patients (pts)," (Poster Presentation #311, Bing-Bing Yang, Mon., Nov. 1)

ABX-PTH

The following three abstracts for ABX10241 (also known as ABX-PTH), the company's fully human monoclonal antibody that targets and neutralizes the action of parathyroid hormone (PTH), will be presented at the 26th Annual Meeting of the American Society for Bone and Mineral Research (ASBMR) in Seattle, Wash., Oct. 1 - 5, 2004:

--"Generation and Therapeutic Potential of ABX10241, A Fully Human Neutralizing Monoclonal Antibody to Human Parathyroid Hormone," (Oral Presentation #1201, Tue., Oct. 5)

--"Treatment of Parathyroid Carcinoma with ABX10241, a Monoclonal Antibody to Parathyroid Hormone," (Poster Presentation #SA498, Sat., Oct. 2)

--"A Phase 1, Single-Dose Study of ABX10241, A Fully Human Monoclonal Antibody to Parathyroid Hormone Secondary Hyperparathyroidism (SHPT) Patients," (Poster Presentation #SU530, Sun., Oct. 3)

The following two abstracts for ABX-PTH will be presented at the American Society of Nephrology (ASN) 37th Annual Meeting & Scientific Exposition in St. Louis, Mo., Oct. 29 - Nov. 1, 2004:

--"Results of a Double-Blind, Single Dose, Dose Escalation Study of a Fully Human Monoclonal Antibody to PTH (ABX10241) in Patients with Secondary Hyperparathyroidism (SHPT)," (Oral Presentation, Room 260, Sat., Oct. 30)

--"Treatment of Severe Hyperparathyroidism Secondary to Parathyroid Cancer with ABX10241, a Fully Human Monoclonal Antibody Directed Against Parathyroid Hormone," (Poster Presentation #F-PO981, Fri., Oct. 29)

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 the establishment of collaborations with multiple pharmaceutical and biotechnology companies. For more information on Abgenix, visit the company's website at www.abgenix.com.

Statements made in this press release about Abgenix's technologies, product development activities, collaborative arrangements and process science and manufacturing activities and about its projected financial results and the achievement of milestone or similar payments, 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 success of clinical trials, the progress of research and product development programs, product manufacturing, regulatory approval processes, competitive products and services, future capital requirements 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.

(1) Panitumumab is an investigational product being co-developed by Amgen and Abgenix that is in a new class of targeted cancer treatments known as EGFr inhibitors.