MDRNA, Inc., a leading RNAi-based drug discovery and development company, announced that the US Patent and Trademark Office (US PTO) has allowed patent application US 11/627,863 covering methods for the delivery of a broad array of compounds with pharmacological (biological) activity, including siRNAs, using proprietary targeting peptides that have preferential binding affinity for lung tissue.
"The development of cell and tissue specific delivery technologies remains a key goal in the field of RNAi therapeutics," said Barry Polisky, chief scientific officer of MDRNA. "This patent allowance demonstrates MDRNA's ability to develop targeting technologies for the delivery of RNAi therapeutics by using highly specific peptides from its patented phage display library. We will combine these peptides with our proprietary DiLA2 delivery platform technology to create highly site-specific novel therapies."
The peptides were identified using the Company's proprietary Trp Cage Phage Display library (J Biol Chem. 2007 282(13):9813; US patent 7,329,725). The Trp Cage motif is highly structured allowing for the identification of peptides with high binding affinity for specific cell or tissue types, and avoids the limitations and weak binding often associated with linear peptide libraries. This technology is directly applicable to the Company's DiLA2 delivery platform as peptides are readily conjugated to the amino acid scaffold of a DiLA2. Peptides capable of directed delivery are expected to further improve the delivery efficiency of UsiRNAs, which have demonstrated significant knockdown of target genes in mouse models of liver and bladder cancer, and in non-human primates.
"Our scientific team continues to develop a broad set of delivery strategies for RNAi-based therapies," said J. Michael French, President and CEO of MDRNA. "With our ongoing collaboration with the University of Helsinki for the discovery of novel peptides from our proprietary Trp Cage Library, we expect further advances for effective targeting and delivery of siRNAs. The identification of additional peptides with high affinity to specific cell types, including certain cancers, is expected and will further expand the Company's patent estate."
A patent allowance confirms the substantive examination of a patent application and will result in a final issuance of a US patent after an administrative process is completed.
MDRNA has a broad intellectual property estate that encompasses four key RNAi technology platforms: siRNA constructs, chemistry, nucleic acid delivery, and gene targets. The MDRNA-owned siRNA constructs and chemistry include its proprietary UsiRNA construct, which is a duplex siRNA chemically modified with non-nucleotide acyclic monomers (UNAs), and is distinct from the standard siRNA construct used by others in the industry. UsiRNAs are fully recognized by the RNAi machinery and provide for potent RNAi activity while specific placement of UNAs in a duplex siRNA minimizes potential off-target effects by the guide strand and reduces undesired passenger strand activity. Furthermore, UsiRNAs escape the surveillance mechanisms associated with cytokine induction, and provide protection from nuclease degradation.
The MDRNA delivery platforms include DiLA2 and nanoparticle forming peptides. DiLA2 is a MDRNA proprietary delivery platform of novel synthetic di-alklylated amino acid compounds used to make liposomal delivery formulations. The DiLA2 platform enables MDRNA to tailor the charge, linker and acyl chains of amino acids in order to configure liposomes for delivery to target tissues 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. The MDRNA peptide nanoparticle platform includes exclusively in-licensed and developed IP surrounding the use of peptides for nanoparticle formulations that increase cellular uptake and endosomal release of siRNAs. MDRNA is currently biopanning its patented phage display library to identify additional peptides for targeted delivery, cellular uptake and endosomal release of siRNA.
MDRNA owns or controls 4 issued patents and has more than 40 pending patent applications, 126 pending foreign patent applications and 6 PCT applications.
MDRNA is a biotechnology company focused on the development and commercialization of therapeutic products based on RNA interference (RNAi).