AVI Biopharma Adds Vaccine Perspective to International Therapeutic Antibodies Conference.

Business Editors, Health/Medical Writers

PORTLAND, Ore.--(BW HealthWire)--June 30, 2000

AVI scientist presents data on its cancer vaccine AVICINE(TM)

and monoclonal antibodies targeted to the vaccine.

AVI BioPharma, Inc. (Nasdaq:AVII) (Nasdaq:AVIIW) (Nasdaq:AVIIZ) scientist Paul Yoshihara, Ph.D., Director of Immunology, presented data this week at an international pharmaceutical conference, on using cancer vaccines to develop therapeutic antibodies.

AVI recently began preclinical development of two human monoclonal antibodies for treating cancer.

The conference, called "Future Trends in Therapeutic Antibodies," was held June 28-29 in London. It provided a forum for the scientists to discuss the increasing importance of this economically viable new class of drugs.

Dr. Yoshihara joined AVI collaborators Abgenix Inc. and XTL Biopharmaceuticals, Ltd, as well as other leading biotechnology and pharmaceutical company representatives from Genzyme Transgenics, Human Genome Sciences and Medarex, among others.

"The dual approach to therapy may provide an effective treatment for patients whose immune systems are compromised, particularly if their only current therapeutic choice is aggressive, toxic chemotherapy," said Dr. Yoshihara. "The antibodies also are promising as anti-tumor targeting agents, with potential to provide effective treatment without the harmful side effects associated with most cancer therapies."

Denis R. Burger, Ph.D., Chief Executive Officer of AVI, said, "There's a significant and growing worldwide interest in using antibodies to treat disease, as evidenced by the attendance of respected industry experts at this international conference. AVICINE's clinical trials are well under way and we have already initiated work on the human monoclonal antibodies. These drug candidates position us well to meet the future demand for cancer-fighting antibodies, either as standalone drugs, as a supplement to our vaccine, or as delivery agents for other cancer therapeutics."

AVI initiated its preclinical development of its two human monoclonal antibodies for cancer in January. Those monoclonal antibodies were produced using Avicine, now in late-stage clinical development, and Abgenix Inc.'s (Nasdaq:ABGX) XenoMouse(TM) technology, which AVI has licensed.

Antibodies are proteins produced by certain white blood cells, called lymphocytes, in response to a foreign stimulus like a virus, to neutralize or help the body to fight the stimulus. A monoclonal antibody is a type of antibody developed in the laboratory and derived from a single (mono) cell line.

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, 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 clinical trials of Resten-NG(TM) in cardiovascular restenosis, the first application of its novel third-generation NEUGENE(R) 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.