AVI BioPharma Begins Phase II Clinical Trials of Its Gene-Targeted Drug for Cardiovascular Restenosis; Human Genetic Code Forms the Basis For AVI's NeuGene Antisense Drug, Resten-NG.

Health/Medical Writers

PORTLAND, Ore.--(BW HealthWire)--June 28, 2000

AVI BioPharma, Inc. (Nasdaq:AVII)(Nasdaq:AVIIW, AVIIZ), announced that it has initiated Phase II human clinical trials of Resten-NG.

The first compound from its novel, third generation NEUGENE(R) antisense technology platform to enter a Phase II trial, Resten-NG targets the genetic sequence c-myc, a gene responsible for initiating cell replication.

Resten-NG will be evaluated in cardiovascular restenosis, the reclosing of the artery through rapid cell replication following balloon angioplasty. This complication occurs in 20 to 40 percent of patients. The study will evaluate efficacy of Resten-NG in treating this complication in 120 patients undergoing the angioplasty procedure.

The study will be conducted at Lenox Hill Hospital in New York, a leader in the diagnosis and treatment of coronary artery disease, under the direction of Drs. Jeffrey Moses and Martin Leon. Lenox Hill's cardiovascular division performs 2,700 balloon angioplasties annually.

"We are pleased to be at the forefront of this exciting new phase of gene-targeted drug development. AVI is one of only a handful of companies that can immediately take advantage of data from the human genome project to bring antisense compounds into human clinical trials," stated Denis R. Burger, Ph.D., CEO of AVI. "Based on the excellent preclinical results and Phase I data, we expect this Phase II trial to bring us closer to fulfilling the therapeutic promise other antisense technologies have struggled or failed to meet."

The rigorous Phase I study that was completed in April did not identify any drug-related safety issues such as adverse events or significant changes in blood chemistry, hematology or coagulation parameters. Additionally, there were no noted alterations in organ systems such as the bone marrow or liver or kidney function.

Extensive preclinical studies in treating restenosis indicate Resten-NG preserves vessel passageways and prevents arterial wall thickening. Delivering the compound to the site of angioplasty blocks the growth and proliferation events in the vessel walls. These studies also indicated that Resten-NG was considerably more effective, stable and potent, and less toxic than other antisense agents in clinical development.

Lenox Hill Hospital is a 652-bed facility that is part of the Lenox Hill Healthcare Network, and a major teaching affiliate of NYU Medical Center. The hospital has earned a national reputation for providing the highest quality care to patients and for contributing to progress in research. It is particularly well known for its cardiac care.

The study is being managed by AVI BioPharma. Individuals interested in enrollment information for the Phase II study, should call 206/285-5588.

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), a therapeutic cancer vaccine, is undergoing 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. 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 has recently completed Phase I trials for restenosis. More information about AVI is available on the Company's website at 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.