AVI BioPharma Enters Phase I Testing of Oral Formulation of its NEUGENE Antisense Compound, Resten-NG.

Business Editors, Health/Medical Writers

PORTLAND, Ore.--(BW HealthWire)--July 19, 2000

AVI BioPharma, Inc. (Nasdaq:AVII)(Nasdaq:AVIIW)(Nasdaq:AVIIZ) today announced it will initiate Phase I testing of oral delivery of its proprietary antisense compound Resten-NG(TM), a gene-targeted therapeutic drug for cardiovascular restenosis.

Resten-NG is part of AVI's third-generation NEUGENE(R) antisense technology platform. These studies are applicable to both the cardiovascular and anti-cancer formulation of the drug.

MDS Harris, a contract research organization, will conduct the Phase I trials beginning July 28. The study will evaluate the pharmacological action of oral delivery of the AVI compound. A key determinant in oral delivery research is the level of bioavailability -- the extent to which a drug or other substance becomes available to the target tissue after administration.

"Low bioavailability has been a problem for other antisense compounds, but preclinical studies of our oral antisense technology suggest bioavailability of our oral NEUGENE compounds will be significantly higher than these others," said Patrick L. Iversen, Ph.D., AVI's Senior Vice President of Research and Development. "Bioavailability results of our preclinical trials in our injectable formulation were consistent with what we saw in the Phase I human clinical trials, and we expect to see the same consistency with our oral antisense agent."

The company successfully completed the Phase I study of Resten-NG administered by injection in March. That study indicated that Resten-NG is more effective, specific and stable than second-generation compounds now in clinical development by others. Resten-NG is now in Phase II clinical trials.

"As demonstrated by our collaboration with DepoMed Inc. last month, we're committed to developing broadly applicable oral formulations of our NEUGENE compounds. These trials are the next step in reaching that goal," said Denis R. Burger, Ph.D., Chief Executive Officer of AVI. "With oral delivery, our drug candidates will be easier and less costly to administer and market. Oral drugs are also more convenient for patients. All of these factors will become more significant as our antisense compounds are studied as cancer treatments and as alternatives to antibiotics."

Most human disease arises from genes that are malfunctioning, such as one's own genes, or genes from infecting agents. AVI's proprietary gene-targeting technology works by stopping the malfunctioning gene's disease-causing actions.

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), is in 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. AVI has begun Phase II clinical trials of Resten-NG in cardiovascular restenosis, the first application of its novel third-generation NEUGENE antisense technology. 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. More information about AVI is available on the Company's website 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.