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Posted: May 19, 2009
MDRNA Announces Positive In Vivo Efficacy Data For Its Proprietary UsiRNA Constructs
(Nanowerk News) MDRNA, Inc. announced today positive in vivo efficacy data showing that its proprietary UsiRNA constructs are highly potent and highly specific against ApoB and Factor VII message. The data are being presented today by Michael V. Templin, Ph.D., Vice President, Discovery Research and Pharmaceutical Development of MDRNA, at the TIDES Oligonucleotide and PeptideŽ Technology and Product Development Conference in Las Vegas, Nevada.
"Data from recent in vivo studies using our UsiRNAs targeting ApoB message confirm that RNA interference is the mechanism of action by which knockdown occurs, giving us high confidence that our UsiRNAs work by a sequence-specific mechanism," stated Barry Polisky, Ph.D., Chief Scientific Officer of MDRNA. "Data from the Factor VII studies indicate that a siRNA in our lead formulation achieved greater than 90% knockdown at 1 mg/kg with duration of effect of up to 28 days. This level of inhibition and duration of effect meets or exceeds published data for Factor VII."
Dr. Polisky added, "Data from rodent studies with our DiLA2 delivery system also continue to show encouraging results, with potency, specificity and duration of effect data now achieved for four independent liver targets, including ApoB, PCSK9, DGAT2 and Factor VII. The absence of histological changes in the liver with doses up to 9 mg/kg in rodents confirms that our DiLA2 liposomes are well tolerated."
UsiRNAs are duplex siRNAs that are modified with non-nucleotide acyclic monomers, termed unlocked nucleobase analogs (UNA), in which the bond between two adjacent carbon atoms of ribose is removed. UsiRNAs are fully recognized by the RNAi machinery and provide for potent RNAi activity. Placement of UNA within UsiRNA minimizes the potential for off-target effects by the guide strand as well as undesired activity of the passenger strand. Further, the change in sugar structure renders this unlocked nucleobase analog conformationally flexible. The flexibility of the monomer escapes the body's surveillance mechanisms associated with cytokine induction, as well as providing protection from nuclease degradation.
About the DiLA2 Delivery Platform
DiLA2 is MDRNA's proprietary platform technology for creating novel liposomal delivery systems from amino acids. The platform enables MDRNA to tailor the charge, linker and acyl chains of amino acids in order to optimize the liposome for delivery to the target tissue of interest. In addition, the platform is designed to permit attachment of various peptides and other targeting molecules to improve a variety of delivery characteristics. In addition, MDRNA is utilizing peptides for nanoparticle formulations to increase cellular uptake and endosomal release.