AVI BioPharma And ImmunoTherapy Corporation Select Pharmaceutical Research Associates to Initiate Phase II Clinical Trials of AVICINE In Prostate Cancer Patients.

PORTLAND, Ore.--(BW HealthWire)--July 15, 1998--AVI BIOPHARMA (AVI)(Nasdaq: AVII, AVIIW) and ImmunoTherapy Corporation (ITC) today selected Pharmaceutical Research Associates (PRA), a leading contract research organization, to conduct a Phase II clinical study of the therapeutic cancer vaccine, AVICINE(tm), for the treatment of prostate cancer. This trial will mark the first time this type of therapeutic vaccine has been used to study its effect on Prostate Specific Antigen (PSA) levels.

A total of 24 prostate cancer patients will be evaluated in the Phase II trial, which will monitor quality of life benefits, tumor suppression and PSA levels in treated patients. PRA will conduct the multi-center study in the United States to conform with both U.S. and European regulatory approval requirements. AVICINE is being manufactured under GMPs for these clinical studies and patient enrollment is expected to begin in the next two to three months with a total study time of approximately one year.

Dr. Richard Angelo, Project Manager for PRA, stated, "PRA is committed to providing AVI and ITC with the expertise required to complete this important clinical evaluation. Our dedicated clinical team is uniquely qualified to provide high-quality service that advances AVICINE's development."

Denis R. Burger, Ph.D., President and CEO of AVI BioPharma and Jeffrey Lillard, Managing Officer of ITC, stated, "We look forward to working with PRA in conducting an additional late-stage study of our therapeutic cancer vaccine, AVICINE. By early 1999, we expect to have three late stage cancer studies in progress including a Phase III licensing trial in colorectal cancer, a Phase II/III trial in pancreatic cancer and a Phase II study in prostate cancer. We are excited about our strong cancer vaccine technology, which we believe is well complemented by our unique antisense and drug delivery platforms. Together, these programs represent a dynamic development portfolio for the treatment of cancer and life-threatening diseases. We remain encouraged by the data we have observed in each of these areas to date and are actively seeking strategic partners who will share our vision and accelerate our development efforts."

To date, more than 125 cancer patients have been treated with AVICINE, which completed Phase II multi-center clinical studies for pancreatic cancer and metastatic colorectal cancer in early 1998. These trials provided evidence of objective anti-tumor responses, stabilization of tumor growth and apparent survival and quality of life benefits in some patients.

AVI BioPharma, formerly known as AntiVirals Inc., is dedicated to the development and commercialization of products for the treatment of life-threatening diseases. In the antisense field, the company has 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 cancer and restenosis, a cardiovascular disease. The company has also developed a drug delivery technology, called CYTOPORTER(tm), which may be useful in improving delivery of many FDA-approved drugs, drugs in development, and antisense compounds. In February 1998, AVI BioPharma and ITC entered into an agreement whereby AVI will acquire ITC. The acquisition has been approved by the Board of Directors of both companies and is pending ITC and AVI shareholder approval.

"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.

   CONTACT: AVI BioPharma
             Denis R. Burger, Ph.D.
             President & CEO
             Alan P. Timmins
             COO & CFO
             503/227-0554
                  or
             Investor Relations Contact:
             CPR Financial Communications, LLC
             Olga M. Fleming
             Sue L. Yeoh
             201/641-1911