MDRNA, Inc. Announces Patent Allowance Covering Methods for Targeted siRNA Delivery to the Lung

BOTHELL, WA--(Marketwire - December 17, 2009) - 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 allowed patent application U.S. 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, Ph.D., 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; 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.

"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 U.S. patent after an administrative process is completed.

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 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.

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, lipid 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 lipid-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.

Contact Information: Contacts: MDRNA, Inc.: Mark Bales, Ph.D. IP Counsel (425) 908-3634 mbales@mdrnainc.com Westwicke Partners (Investors): Stefan Loren, Ph.D. (443) 213-0507 sloren@westwicke.com John Woolford (443) 213-0506 john.woolford@westwicke.com McKinney|Chicago (Media): Alan Zachary (312) 944-6784 x 316 (708) 707-6834 azachary@mckinneychicago.com