AVI BioPharma Is Cleared to Initiate Clinical Trial for West Nile Virus With NeuGene Antisense Drug.

Business Editors/Health/Medical Writers

PORTLAND, Ore.--(BUSINESS WIRE)--Aug. 4, 2003

AVI BioPharma, Inc. (Nasdaq:AVII) (Nasdaq:AVIIW) (Nasdaq:AVIIZ), today announced that it has satisfied all regulatory requirements for initiating a multicenter Phase Ib clinical trial with its NEUGENE(R) drug AVI-4020 in patients hospitalized with West Nile virus (WNV). Study initiation activities are in progress, and the trial is expected to begin this summer.

AVI collaborated with the National Institute of Allergy and Infectious Diseases (NIAID) and Dr. Richard Whitley, the project director of NIAID's Collaborative Antiviral Study Group, to develop and test AVI-4020 against WNV and to prepare the clinical protocol. Dr. Whitley will serve as the principal investigator for the clinical trial. The multicenter trial sites are expected to include the Mayo Clinic and other leading institutions in areas hard-hit by WNV.

"Robust preclinical data on AVI-4020 and safety data from previous NEUGENE clinical trials, and the lack of existing treatments for WNV all build a strong case for this clinical program," said Denis R. Burger, Ph.D., chief executive officer at AVI. "Our NEUGENE antisense platform represents a novel approach to the rapid development of drugs to combat emerging infectious diseases. In the case of WNV, we have gone from identification of the drug candidate to initiating the clinical program in just nine months, which is a significant accomplishment."

About West Nile Virus

In 2002, the Centers for Disease Control and Prevention (CDC) recorded 4,156 cases of WNV infection, resulting in 284 deaths. Outbreaks in 2003 have been more widespread than in 2002. Although it is very early in the West Nile season, case numbers are now increasing rapidly, with the CDC reporting 69 cases of WNV, with three deaths, as of Aug. 1, 2003, up from the 11 cases reported approximately one week prior.

Most people who become infected with WNV have no symptoms, though about 20 percent develop mild, flulike symptoms, including fever, headache, body aches, and occasionally a rash and swollen lymph glands. In its most serious manifestations, WNV infection may cause life-threatening inflammation of the brain (encephalitis) or inflammation of the membrane surrounding the brain and spinal cord (meningitis), as well as a number of other significant neurologic symptoms, including muscle paralysis similar to that seen with poliovirus infections and others that mimic the symptoms of Parkinson's disease.

About AVI BioPharma

AVI BioPharma develops therapeutic products for the treatment of life-threatening diseases using two technology platforms: third-generation NEUGENE antisense drugs and cancer immunotherapy. AVI's lead NEUGENE antisense compound is designed to target cardiovascular restenosis, cancer, polycystic kidney disease and other cell proliferation disorders. In addition to targeting specific genes in the body, AVI's antiviral program uses NEUGENE antisense compounds to target single-stranded RNA viruses, including West Nile virus, SARS coronavirus, calicivirus and hepatitis C. AVI's second technology, AVICINE(R), is a therapeutic cancer vaccine with late-stage trials planned for the treatment of pancreatic and colorectal cancer. More information about AVI is available on the company's Web site 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 preclinical 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.