MDRNA, Inc. Presents Positive Efficacy and Tolerability Data in Non-Human Primates With Proprietary siRNA Compounds

BOTHELL, WA--(Marketwire - December 3, 2009) - MDRNA, Inc. (NASDAQ: MRNA), a leading RNAi-based drug discovery and development company, today announced presentation of data related to its non-human primate and oncology programs at the Informa Life Science 10th Annual Conference, EuroTIDES, taking place in Amsterdam, The Netherlands. Michael V. Templin, Ph.D., Vice President of Discovery Research and Pharmaceutical Development at MDRNA, Inc., today presented data on efficacy and tolerability in non-human primates with the Company's novel UsiRNA construct and DiLA2 delivery platforms for the development of RNAi-based therapeutics.

Dr. Templin stated that the non-human primate program, which began four months ago, resulted in the significant knockdown of a primate liver gene following a single intravenous (systemic) dose of 0.3 mg/kg. No increase in ALT and AST levels were observed at 24 or 48 hours post-dose nor was there elevation in other liver enzymes or kidney function markers. In addition, there were no alterations in hematology parameters and no apparent induction of cytokines.

Dr. Templin also presented new data from the Company's oncology therapeutics programs. In models of liver and bladder cancer, UsiRNAs against Survivin and PLK-1, two genes considered to play critical roles in tumor growth, have demonstrated potent anti-tumor effects when delivered with the Company's proprietary DiLA2 liposome formulations via systemic (liver cancer) and local (bladder cancer) administration. In orthotopic (within the liver) liver cancer, > 60% knockdown of survivin mRNA was found, and compared to negative controls a 65% decrease in tumor weights occurred in UsiRNA-treated mice. This was similar to the tumor growth inhibition in positive control Avastin® (bevacizumab)-treated mice. Potent anti-cancer activity was also demonstrated for bladder cancer with up to 90% reduction in survivin mRNA. There was a dose-dependent decrease in bioluminescence of up to 90%, indicating significant reduction in tumor burden compared to vehicle and scrambled UsiRNA controls. Importantly, in each model, the mechanism was confirmed to be via RNA interference.

"Our non-human primate program is fundamental to the continued development of our oncology programs and the overall advancement of our RNAi drug discovery platform," said J. Michael French, President and Chief Executive Officer of MDRNA. "These data further corroborate the potency and tolerability of our UsiRNA/DiLA2 compounds. With the rapid advancement of our non-human primate program over the last few months, we are encouraged with the positive progress and feel strongly that we have a robust approach to the development of RNAi-based therapeutics."

The presentation given by Dr. Templin is posted on the Company website homepage at: www.mdrnainc.com.

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.

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: Contact: MDRNA, Inc.: Peter Garcia Chief Financial Officer (425) 908-3603 pgarcia@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 or (708) 707-6834 azachary@mckinneychicago.com