AVI Announces Promising NeuGene Antisense Results Targeting Viruses
Preclinical Results On West Nile Virus, Hepatitis C Virus and Calicivirus
PORTLAND, Ore. - Dec. 5, 2002 - AVI BioPharma, Inc. (Nasdaq: AVII, AVIIW, AVIIZ) today announced promising preclinical results from targeting single stranded RNA viruses with its proprietary NeuGene® antisense drugs. The viral program, led by Patrick L. Iversen, Ph.D., AVI's senior vice president of research and development, has focused primarily on one family of viruses that includes West Nile virus, hepatitis C virus (HCV) and Calicivirus.
"The significant amount of attention now being focused on viruses in our environment, both naturally occurring viruses, and those with the potential for being used in biological warfare, parallels AVI's ongoing emphasis on the use of NeuGene antisense compounds as antiviral drugs," Dr. Iversen said. "We've seen encouraging results in studies on three similar viruses including West Nile virus, HCV and Calicivirus. Norwalk virus, the virus currently plaguing the cruise ship industry, is another single-stranded RNA virus from the same family."
West Nile Virus
AVI recently treated a group of three Humboldt penguins at the Milwaukee
County Zoo suffering from a natural outbreak of West Nile virus. The
study tested the hypothesis that NeuGene antisense drugs targeting West
Nile virus will be effective against the infection. All three penguins
have lived for over one-and-a-half months since treatment.
This positive outcome differed from that of 10 flockmates who died from West Nile virus at the same zoo, as reported in an article in the Wisconsin State Journal dated Oct. 4, 2002. The illness began in the penguins with weight loss and progressed to death in one to two days. Progression was slowed by aggressive intravenous nutritional support, but the infected penguins still died within 10 days. In contrast, the NeuGene-treated penguins survived and the characteristic weight loss from the virus was blocked.
West Nile virus is spread by the bite of an infected mosquito, and can infect people, horses, many types of birds and some other animals. West Nile virus infection can result in severe and sometimes fatal illnesses.
Hepatitis C Virus
In collaboration with XTL Pharmaceuticals in Israel, AVI used a
propriety animal model to evaluate antisense efficacy in treating active
HCV infections from clinical isolates. These studies identified NeuGene
antisense drugs that are effective against HCV infections. AVI plans to
initiate clinical trials against HCV in 2003.
Hepatitis C virus (HCV) is a single-stranded RNA virus like West Nile virus and Calicivirus. Approximately 170,000,000 people worldwide and 4,000,000 in the United States are infected with HCV. The virus is transmitted primarily by blood and blood products.
Calicivirus
AVI recently completed a preclinical test against a spontaneous outbreak
of hemorrhagic Feline Calicivirus at a Georgia animal rescue shelter.
Twenty-four cats infected with the virus displayed numerous symptoms,
including upper respiratory problems, conjunctivitis, peripheral edema
and hemorrhages. The median survival time for animals in the untreated
group was three days. No median survival time could be defined in the
treated group because over 85 percent are long-term survivors.
These data are considered to be highly significant in that the Feline Calicivirus is closely related to the Norwalk virus. Norwalk virus has been identified as the cause of over 1,000 infections on five different cruise ships over the past month. The observations in Feline Calicivirus are considered to represent an appropriate animal model for treatment of Norwalk viral infections in humans.
Calicivirus infections, for which no specific treatment regimens currently exist, are usually severe and can result in diarrhea, hepatitis, encephalitis, pneumonia, hemorrhage and other symptoms. Approximately 175 known Calicivirus isolates have been recovered in animals ranging from shellfish to whales. Many of these isolates are capable of infecting humans, including the Norwalk virus, a member of the Calicivirus family. AVI licensed a patent for Calicivirus diagnosis and treatment from Oregon State University in February 2002.
Neugenes Versus Viruses
When antisense compounds bind to a disease-causing gene sequence, the
genetic process is inhibited, and thus the pathogen or pathogenic
process is disabled. In the case of single-stranded RNA viruses, the
described results demonstrate in animals that the NeuGene compound will
bind to the virus at a specific site on the sequence and prevent the
virus from replicating. In effect, the NeuGene shuts down the virus,
thereby enabling the immune system to manage the ongoing infection.
About AVI BioPharma
AVI BioPharma develops therapeutic products for the treatment of life-threatening diseases using two technology platforms: NeuGene antisense drugs and cancer immunotherapy. Its lead cancer agent, AVICINE®, a therapeutic cancer vaccine, has completed three Phase II trials in colorectal and pancreatic cancer and is initiating a Phase III pivotal trial in pancreatic cancer, with a supporting study 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 and in a Phase I/II trial for cancer. AVI has completed a Phase I NeuGene antisense study that successfully down-regulated the liver enzyme cytochrome P450 and modified drug metabolism, and a Phase I/II trial in polycystic kidney disease. 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.