MDRNA, Inc. Announces Patent Allowance Covering Methods for Cell Specific Delivery of siRNAs

BOTHELL, WA--(Marketwire - March 29, 2010) - MDRNA, Inc. (NASDAQ: MRNA), a leading RNAi-based drug discovery and development company, today announced that the U.S. Patent and Trademark Office (USPTO) has issued a Notice of Allowance for patent application U.S. 12/701,397 covering methods for the delivery of siRNAs as well as a broad array of compounds with pharmacological activity. The patent identifies and protects peptides that were discovered using MDRNA’s proprietary Trp Cage Phage Display Library and describes targeting peptides that demonstrate high binding affinity to, and internalization by, hepatocellular carcinoma cells.

“Specificity to individual cell types and internalization are key attributes required for peptide-directed delivery,” said Barry Polisky, Ph.D., Chief Scientific Officer of MDRNA. “The Trp Cage Phage Display Library is proving to be a robust means to screen and identify peptides that impart these targeting characteristics. The addition of these novel peptides to our proprietary DiLA2 delivery platform technology permits the potential development of highly tissue- and cell-specific RNAi-based therapies for the treatment of cancers in which the need to differentiate between normal and diseased cells is important.”

MDRNA’s proprietary Trp Cage Phage Display Library (J Biol Chem. 2007 282(13):9813) is the subject of an issued patent, U.S. 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.

“This is the second Notice of Allowance that we have received in the past four months from the USPTO for a patent application that covers the use of our proprietary targeting peptide technology,” said J. Michael French, President and CEO of MDRNA. “We are pleased that the USPTO recognizes the novelty and significance of our proprietary peptide targeting technology. The identification of additional peptides with high affinity to specific cell types, including certain cancers, further strengthens our broad patent estate.”

On December 17, 2009, MDRNA received a Notice of Allowance from the USPTO for patent application U.S. 11/627,863, which covers the use of targeting peptides that have preferential binding affinity for lung tissue.

About MDRNA’s Technology

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 an 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 16 issued or allowed patents, and has 36 pending patent applications, 126 pending foreign patent applications and 7 PCT applications.

About MDRNA, Inc.

MDRNA is a biotechnology company focused on the development and commercialization of therapeutic products based on RNA interference (RNAi). Our goal is to improve human health through the development of RNAi-based compounds and drug delivery technologies that together provide superior therapeutic options for patients. Over the past decade, we have developed substantial capabilities in molecular biology, cellular biology, amino acid chemistry, peptide chemistry, pharmacology and bioinformatics, which we are applying to a wide range of RNAi technologies and delivery approaches. These capabilities plus the in-licensing of key RNAi-related intellectual property have rapidly enabled us to become a leading RNAi-based therapeutics company with a pre-clinical pipeline in oncology. Through our capabilities, expertise and know-how, we are incorporating multiple RNAi technologies as well as peptide- and liposomal-based delivery approaches into a single integrated drug discovery platform that will be the engine for our clinical pipeline as well as a versatile platform for establishing broad therapeutic partnerships with biotechnology and pharmaceutical companies. We are also investing in new technologies that we expect to lead to safer and more effective RNAi-based therapeutics while aggressively building upon our broad and extensive intellectual property estate. By combining broad expertise in siRNA science with proven delivery platforms and a strong IP position, MDRNA is well positioned as a leading RNAi-based drug discovery and development company. Additional information about MDRNA, Inc. is available at http://www.mdrnainc.com.

MDRNA Forward-Looking Statements

Statements made in this news release may be forward-looking statements within the meaning of Federal Securities laws that are subject to certain risks and uncertainties and involve factors that may cause actual results to differ materially from those projected or suggested. Factors that could cause actual results to differ materially from those in forward-looking statements include, but are not limited to: (i) the ability of MDRNA to obtain additional funding; (ii) the ability of MDRNA to attract and/or maintain manufacturing, research, development and commercialization partners; (iii) the ability of MDRNA and/or a partner to successfully complete product research and development, including preclinical and clinical studies and commercialization; (iv) the ability of MDRNA and/or a partner to obtain required governmental approvals; and (v) the ability of MDRNA and/or a partner to develop and commercialize products that can compete favorably with those of competitors. Additional factors that could cause actual results to differ materially from those projected or suggested in any forward-looking statements are contained in MDRNA’s most recent periodic reports on Form 10-K and Form 10-Q that are filed with the Securities and Exchange Commission. MDRNA assumes no obligation to update and supplement forward-looking statements because of subsequent events.