MDRNA to Present Data on Tumor Reduction at Cancer Therapy Conference

BOTHELL, WA--(Marketwire - October 29, 2009) - MDRNA, Inc. (NASDAQ: MRNA), a leading RNAi-based drug discovery and development company, today announced the presentation of data related to its RNAi oncology programs at the 24th Annual Meeting of the International Society for Biological Therapy of Cancer, taking place October 28-31, 2009 at the Gaylord National Hotel and Convention Center in Washington, D.C. Shaguna Seth, Ph.D., Director of Discovery Research and Pharmaceutical Development, will present data detailing an emerging approach to cancer therapy by harnessing RNA interference to silence aberrant expression of genes linked to cancer.

"Development of Novel RNAi-based Therapeutics Targeting Survivin for Treatment of Liver and Bladder Cancer," presented by Dr. Seth, describes anti-tumor activity of a proprietary siRNA construct, termed UsiRNA, targeting survivin, a key protein in the progression of cancer, in an orthotopic model of liver cancer and an orthotopic model of bladder cancer. The UsiRNA was delivered with the Company's proprietary DiLA2 liposome formulations via systemic (liver cancer) and local (bladder cancer) administration.

In liver cancer, treatment with survivin UsiRNA in DiLA2 liposomes resulted in >60% knockdown of survivin mRNA during twice weekly dosing over a three-week period, and knockdown persisted for an additional three weeks after the last dose. High tumor burden in the vehicle and UsiRNA scrambled control groups prompted study termination at seven weeks, at which time there was a 65% decrease in tumor weights in the survivin UsiRNA-treated group, compared to negative controls. This level of difference was similar to Avastin® (bevacizumab)-treated mice which served as the positive control. Potent anti-cancer activity was also demonstrated for bladder cancer. Twice weekly dosing for two weeks with survivin UsiRNA in DiLA2 liposomes demonstrated an approximately 70% reduction in survivin mRNA during the dosing period and a duration of effect at 11 days post final dose of up to 90% reduction in survivin mRNA. There was a dose-dependent decrease in bioluminescence of up to 90% in UsiRNA-treated mice, indicating significant reduction in tumor volume compared to vehicle and scrambled UsiRNA controls. In both models, the mechanism was confirmed to be via RNA interference, as noted by identification of specific fragments generated by RISC cleavage of survivin mRNA.

"We continue to be encouraged by the progress of our oncology programs," said Dr. Barry Polisky, Chief Scientific Officer of MDRNA. "As we expand our efforts, we expect to explore RNAi mediated knockdown of further potential cancer targets in both disease models. In addition, we plan to assess the impact of combination approaches such as UsiRNAs targeting two separate gene targets as well as the combination of a UsiRNA and a conventional therapy."

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: 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