MDRNA reports positive in vivo efficacy data against flu strains

The company said that the data reported indicate that MDRNA’s dicer substrate small interfering RNAs (siRNAs) are highly active against multiple strains of influenza A virus including seasonal H3N2 and highly pathogenic H5N1 strains. The lead dicer siRNA also elicited high inhibition activity against Tamiflu-resistant strains of influenza virus, the company added.

It is reported that treatment with MDRNA’s lead candidate before and after infection resulted in a 100 to 1,000-fold (99%) reduction in viral titers, thus demonstrating its potential use as a therapeutic as well as a prophylactic.

Formulated dicer substrates dosed intranasally showed significant reduction in viral replication, leading to lower viral titers, decreased clinical signs, and increased survival in infected mice and ferret models of influenza, the company said. MDRNA’s proprietary delivery formulations provided greater therapeutic benefit at lower siRNA dose levels, as compared to siRNA dosed without formulation, according to MDRNA.