Abgenix Submits IND Application to FDA for ABX-IL8 in Leading Pulmonary Disease; Third Indication for Anti-inflammatory Antibody Enters Phase II Clinical Trial.

Business Editors/Health & Medical Writers

FREMONT, Calif.--(BW HealthWire)--Sept. 20, 2001

Abgenix, Inc. (Nasdaq:ABGX) today announced that it has submitted an Investigational New Drug (IND) application to the U.S. Food and Drug Administration (FDA) to initiate a Phase IIa clinical trial with ABX-IL8 in patients with chronic obstructive pulmonary disease (COPD). ABX-IL8 is the company's lead fully human monoclonal antibody generated with XenoMouse(R) technology that blocks the activity of interleukin-8 (IL-8), a chemokine involved in several inflammatory diseases. With the start of the COPD trial, Abgenix's clinical program now includes three Phase II clinical trials with ABX-IL8, including an ongoing Phase IIb trial in psoriasis and a Phase IIa clinical trial in rheumatoid arthritis that has recently completed enrollment.

"Abgenix is excited about the clinical potential of ABX-IL8 in various inflammatory diseases," said R. Scott Greer, chairman and chief executive officer of Abgenix. "COPD, the third indication to be explored, represents another substantial market opportunity for our lead anti-inflammatory product candidate. COPD is a chronic and debilitating disease afflicting millions of Americans and we are hopeful that ABX-IL8 will prove useful in treating the disease."

The Phase IIa trial is a double-blind, placebo-controlled study designed to evaluate the efficacy and safety of ABX- IL8 in COPD. The study is designed to include a total of 150 patients across approximately 15 clinical sites in the U.S. Patients will receive a total of three doses of ABX-IL8 administered monthly over a two-month period. Efficacy analyses will focus on change in airflow (spirometry), dyspnea (breathlessness) and disease-related quality of life. Assuming patient enrollment is completed on schedule, results of the study are expected in the first quarter of 2003.

ABX-IL8 is a fully human monoclonal antibody directed against interleukin-8 (IL-8), a chemokine that is produced at sites of inflammation and attracts and activates inflammatory cells such as neutrophils. Elevated levels of IL-8 in the broncho-alveolar fluid and the lung tissue of COPD patients have been correlated with the number of infiltrating neutrophils. Neutrophil enzymes including elastase have been implicated in the chronic destruction of lung tissue in patients with COPD. Antibodies to IL-8 have been shown to block neutrophil migration in preclinical studies.

COPD is a chronic disease marked by inflammation and progressive de-truction of lung tissue resulting in dyspnea (shortness of breath), persistent cough, recurrent infections and chronic debilitation. Current treatments available today for COPD such as bronchodilators, steroids, antibiotics and expectorants, provide only symptomatic relief and do not directly address the underlying inflammatory process of the disease. COPD is a major cause of chronic morbidity and mortality worldwide. The disease is currently the fourth leading cause of death in the world. In the U.S., over 15 million people are estimated to suffer from COPD, 60% of whom have a severe form of the disease, with annual health care expenditures exceeding $20 billion.

Abgenix is a biopharmaceutical company focused on the development and commercialization of human monoclonal antibody therapies for a variety of diseases. The company's antibody technology platform, which includes XenoMouse(R) and XenoMax(TM) technologies, enables the rapid generation and selection of high affinity, fully human antibody product candidates to disease targets appropriate for antibody therapy. Abgenix leverages its leadership position in human antibody technology by building a large and diversified product portfolio through the establishment of licensing arrangements with multiple pharmaceutical, biotechnology and genomics companies and through the development of its own internal proprietary products. 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 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 success of clinical trials, the progress of research and product development programs, the regulatory approval process, competitive products, 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.