AVI BioPharma Completes Preclinical Development on NeuGene Antisense Agent with Broad Applications for Use with FDA Approved Drugs.

Business Editors

PORTLAND, Ore.--(BUSINESS WIRE)--Dec. 20, 2000

Company Prepares IND Filing for Phase I Clinical Trials

AVI BioPharma, Inc. (Nasdaq:AVII)(Nasdaq:AVIIW)(Nasdaq:AVIIZ) today announced completion of preclinical studies utilizing its proprietary NEUGENE(R) antisense technology targeting the liver enzyme, cytochrome P450.

This liver enzyme regulates the metabolism of most FDA approved drugs in current use. By using NEUGENES to down-regulate this enzyme, the metabolism of the drug in use is altered, improving both the toxicity profile and the drug effectiveness. This NEUGENE antisense compound showed the potential to enhance the effectiveness of many currently approved drugs, including cancer drugs like Taxol' and transplant drugs like cyclosporin, among many others.

"We're very excited about the implications of these results, and we have already taken steps to move this broadly applicable antisense application through the clinical development pathway," said AVI's CEO Denis R. Burger, Ph.D. "We are finishing GMP manufacturing of this NEUGENE agent and expect to begin human clinical trials early in 2001. Our goal is to bring to market an antisense product that will enhance the therapeutic benefits of a broad range of drugs now in clinical use."

The preclinical studies showed that NEUGENES would alter expression of cytochrome P450 3A4 (CYP3A4) in the liver. CYP 3A4 is a liver enzyme that regulates metabolism of about 60 percent of all FDA approved drugs. Drugs normally broken down by this liver enzyme stayed in an active form much longer, potentially improving their overall effectiveness.

"We were able to change the metabolism of several target drugs in these studies," said AVI's Senior Vice President of Research and Development Patrick L. Iversen, Ph.D. "The result was to improve the disease-fighting capabilities of a broad range of drugs. In the case of drugs like Taxol, the potential result is better anti-cancer activity with fewer side effects."

AVI BioPharma develops therapeutic products for the treatment of life-threatening diseases using two technology platforms: cancer immunotherapy and gene-targeted drugs. Its lead clinical agent, AVICINE(TM), a therapeutic cancer vaccine, is undergoing a Phase II trial in pancreatic cancer, and will soon enter a Phase III pivotal trial in colorectal cancer and a Phase II trial in prostate cancer. The first application of its NEUGENE compounds, Resten-NG, is designed to treat cancer, cardiovascular restenosis and other cell proliferation disorders by inhibiting the production of a cellular transcription factor, the oncogene c-myc. Resten-NG is currently in Phase II trials for cardiovascular restenosis. More information about AVI is available at http://www.avibio.com.

"Safe Harbor" Statement under the Private Securities Litigation Reform Act of 1995. The statements that are not historical facts contained in this release are forward-looking statements that involve risks and uncertainties, including, but not limited to, the results of research and development efforts, the results of pre-clinical and clinical testing, the effect of regulation by the FDA and other agencies, the impact of competitive products, product development, commercialization and technological difficulties, and other risks detailed in the Company's Securities and Exchange Commission filings.