AVI BioPharma NEUGENE Antisense Study Featured In Drug Metabolism and Disposition.

Business Editors and Health/Medical/Biotechnology Writers

AVI BioPharma, Inc. (Nasdaq:AVII)(Nasdaq:AVIIW)(Nasdaq:AVIIZ), today announced that the journal Drug Metabolism and Disposition will feature an article on an AVI study as the cover story in its July issue.

The study demonstrated that AVI's proprietary NEUGENE(R) antisense technology can inhibit a key metabolic enzyme in human liver cells, and was based on preclinical research conducted by AVI scientists Vikram Arora, Ph.D., and Patrick L. Iversen, Ph.D., senior vice president of research and development.

NEUGENE Antisense Technology for Drug Manipulation

In the study, AVI scientists, using primary cultures of human liver from 11 individual donors, demonstrated that NEUGENE antisense technology (AVI-4557) is an effective and specific inhibitor of a key liver enzyme, Cytochrome P450, which controls the metabolism of most drugs. The specific enzyme in the P450 family that AVI targeted with its antisense was CYP3A4, which is responsible for the metabolic breakdown of approximately 50 percent of current FDA-approved drugs. The study results represent a potential strategy for altering dosage and toxicity of clinically-relevant drugs metabolized by this enzyme. The functional utility of this approach was shown through the altered metabolism of two drugs, paclitaxel and cyclophosphamide, in a predictable manner.

"AVI continues to gather a body of evidence that supports the efficacy of its NEUGENE antisense technology," said Denis R. Burger, Ph.D., CEO of AVI. "It is exciting to see a journal of this caliber recognizing the validity and impact of AVI's antisense platform and drug development program."

In May 2002, AVI expanded on this research through the completion of a 96-patient clinical study that showed that its NEUGENE antisense drug can change gene expression in humans. This was the first study of its kind and provided definitive proof that AVI's antisense drugs function in the clinic as predicted. The gene target of this study was also CYP3A4. AVI's NEUGENE antisense drug inhibited the expression of this enzyme, thus changing the metabolism of a test drug (BuSpar(R) (Bristol-Myers Squibb Co.)) in trial participants.

AVI believes that the ability to regulate the metabolism of drugs could be used to enhance efficacy, adjust dosing regimens and improve the safety profile of certain drugs. It also may be used to improve the pharmacokinetics of drugs coming off patent, thereby gaining new patent life. AVI is currently in the process of submitting this study for peer review.

About AVI BioPharma

AVI BioPharma develops therapeutic products for the treatment of life-threatening diseases using two technology platforms: NEUGENE antisense drugs and cancer immunotherapy. Its lead cancer agent, AVICINE(R), a therapeutic cancer vaccine, has completed three Phase II trials in colorectal and pancreatic cancer and is initiating a Phase III pivotal trial in pancreatic cancer, with a supporting study in colorectal cancer. The first application of its NEUGENE compounds, Resten-NG(TM), 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. It is currently in Phase II trials for restenosis and in Phase I/II trials for cancer and polycystic kidney disease. AVI has recently completed a Phase I NEUGENE antisense study that successfully down-regulated the liver enzyme Cytochrome P450 and modified drug metabolism. More information about AVI is available on the Company's Web site 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 preclinical 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.