Data Shows AVI BioPharma Antisense Compounds Regulate Stem Cell Growth; Data Presented at National Stem Cell Symposium Held in Colorado This Week.

Business Editors, Health/Medical Writers

PORTLAND, Ore.--(BW HealthWire)--Feb. 9, 2001

AVI BioPharma Inc. (Nasdaq:AVII) (Nasdaq:AVIIW, AVIIZ), in collaboration with the National Cancer Institute, and University of Washington stem cell research pioneer Steve Bartelmez, Ph.D., presented findings which demonstrate that AVI's NEUGENE(R) antisense technology regulates stem cell proliferation and differentiation.

"Stem cell research has been important to our understanding of critical disease mechanisms. Coupled with this new ability to regulate their proliferation using our antisense technology, we're looking at new paths to understanding and treating numerous life-threatening diseases," said AVI's CEO Denis R. Burger, Ph.D. "These findings also emphasize the breadth of our antisense technology. Based on this data, we expect NEUGENES to play a significant role in the future of stem cell transplantation."

Stem cells, which come from the bone marrow and are the origin for a variety of blood cells, are transplanted into patients with depleted bone marrow due to cancer chemotherapy, radiation, or several other causes. Since stem cells are in low supply and difficult to expand in the laboratory, there is always considerable risk during bone marrow transplantation. The data demonstrate the versatility of AVI's NEUGENE technology in selectively regulating either proliferation or differentiation of bone marrow stem cells. AVI's antisense compound, targeted against the TGF-beta gene, induced dramatic stem cell multiplication without the problems other research in this area has faced. This could potentially eliminate the need for large quantities of stem cells in the bone marrow transplant setting. "Bone marrow transplantation is now essential therapy for several diseases and there is even speculation that an important feature of cancer is stem cells gone awry. Therefore, it is possible that someday we will be able to control cancer and a large number of other diseases, through the same mechanism we saw in this work," said Patrick Iversen, Ph.D., AVI's Senior Vice President of Research and Development. "The presentation of this data signals that we are finishing preclinical development, and hopefully we will be able to bring it to human trials soon."

In addition to blood stem cells, scientists have also isolated neural stem cells from the brain, and stem cells that form muscle, cartilage, fat and other tissue. One advantage of using stem cell transplantation is that they are rarely rejected by the host organism.

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, a therapeutic cancer vaccine, has completed enrollment in a Phase II trial in pancreatic cancer and is in a Phase III pivotal trial in colorectal 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. It is currently in Phase II trials for restenosis. 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.