AVI BioPharma Presents NeuGene-R- Technology at 38th Annual Meeting of the Society of Toxicology.

PORTLAND, Ore.--(BW HealthWire)--March 17, 1999--AVI BIOPHARMA INC. ("AVI")(Nasdaq: AVII, AVIIW) today announced that Patrick L. Iversen, Ph.D., the company's Senior Vice President of Research and Development, joined by Cell Biologist Molly Ghosh, Ph.D. and Pharmacologist John Mata from AVI, will each make presentations concerning AVI's NEUGENE(R) antisense compounds at the 38th Annual Meeting of The Society of Toxicology, March 14-18, 1999 in New Orleans, LA.

The three presentations, entitled "Oligonucleotide-Induced Mutation in Cultured Cells: Characterization, Mechanism and Implications," "An Investigation of the Structural Requirements for Efficacy and Mechanism of Action of a Short Telomere Mimetic Phosphorothioate Oligodeoxynucleotide," and "Bolus Intravenous Injections of Phosphorothioate Oligodeoxynucleotides Cause Severe Hypotension by Acting as Alpha-1 Adrenergic Receptor Antagonists," demonstrate scientific evidence that the company's proprietary third generation antisense compounds, NEUGENES, not only provide pharmacological advantages over second generation compounds including phosphorothioates, but may also have broad applicability as a cancer therapeutic.

Dr. Iversen commented, "These three presentations underscore the intricacy of possible interactions between complex antisense compounds and biological systems. Subtle alterations in the chemical structure of the oligonucleotides, which make up certain antisense compounds, may produce dramatic consequences in their potential toxicity. For over 19 years, AVI has worked tirelessly to overcome the oligonucleotide toxicity challenges faced by first and second generation antisense compounds. As a result of our efforts, we have been able to show that our proprietary third generation antisense compounds have improved efficacy, potency and specificity characteristics, without the associated toxicity."

Denis R. Burger, Ph.D., President and CEO of AVI, added, "We are strongly encouraged by the results of our extensive research and development efforts to date, which further demonstrate the pharmacological advantages of our third generation antisense NEUGENES compounds over competing second generation technologies. With increased potency and less toxicity, we are afforded a much larger therapeutic window for our antisense drugs."

AVI BioPharma Inc. is dedicated to the development and commercialization of products for the treatment of life-threatening diseases using three platforms: immunotherapy for cancer, gene-targeted drugs, and intracellular drug delivery technologies. The company will soon enroll patients into a Phase III licensing trial of its lead clinical agent, AVICINE(tm), an essentially non-toxic cancer vaccine, in colorectal cancer, a Phase II trial in pancreatic cancer and a Phase II trial in prostate cancer. The company has also developed a patented class of gene-targeted drugs, called NEUGENES(R), which may be useful in the treatment of a wide range of human diseases including cardiovascular restenosis and cancer. Further, AVI has developed a novel drug delivery technology, called CYTOPORTER(tm), that may be useful in significantly improving drug uptake while minimizing toxicity for a wide range of FDA approved drugs.

"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.