AVI BioPharma, Inc. presented confirmatory positive results on the inhibition of the SARS coronavirus using its NeuGene antisense drugs. Michael Buchmeier, PhD, of The Scripps Research Institute (TSRI) in La Jolla, Calif., presented the positive findings at the Keystone Symposium on Bioterrorism and Emerging Infectious Diseases in the workshop on SARS.
The cell culture studies evaluated multiple strategies targeting AVI's proprietary NeuGene antisense technology for inhibition of the SARS coronavirus. Several of the design strategies produced positive results of at least a tenfold reduction in viral expression. The most effective NeuGene design strategy interfered with an RNA processing site unique to the SARS class of coronaviruses and resulted in a greater than hundredfold reduction in viral expression. This antisense agent was found to be more than 10 times more potent than any other SARS inhibitor previously reported.
"We believe the studies have identified an effective agent for the potential treatment of SARS," said Patrick Iversen, PhD, senior vice president of research and development at AVI. "AVI's SARS and West Nile virus programs demonstrate that NeuGene antisense technology can respond more quickly than any other drug development technology to produce efficacious agents. Moreover, since these viruses are closely related due to their single-stranded RNA genomes, these studies represent a significant advancement in our understanding of optimal strategies for designing NeuGene drugs against all RNA viruses."
These innovative laboratory studies, conducted at TSRI, demonstrated that NeuGene antisense drugs were effective via three distinct measurements of SARS infection. NeuGenes prevented the SARS viral infection from killing cells, reduced viral spread among cells, and reduced viral replication as measured by viral titer. These significant inhibitory effects were observed at NeuGene concentrations that were shown to be completely nontoxic. The results confirm previous efforts achieved internally at AVI.
"We now have the ability to produce clinical supplies of our SARS drug to meet the potential re-emergence of SARS if this disease becomes a significant medical or economic concern again this year or in the future," said Denis Burger, PhD, CEO at AVI. "Although SARS raised serious medical issues last year, experts remain divided on its significance compared with other viral infectious diseases with seemingly far greater worldwide impact. For this reason, AVI is currently focusing its clinical antiviral programme going forward on the acknowledged most prominent viral diseases including hepatitis C infection and dengue fever."