Marina Biotech, Inc. (Formerly Known as MDRNA, Inc.) Announces Significant Knockdown of a Cancer Target in a Rodent Model of Malignant Ascites

BOTHELL, WA--(Marketwire - March 02, 2011) - Marina Biotech, Inc. (NASDAQ: MRNA), a leading RNAi-based drug discovery and development company, reported data demonstrating significant knockdown of target mRNA in an orthotopic model of malignant ascites with its proprietary UsiRNA construct and DiLA2-based delivery system. The data were presented by Michael V. Templin, Ph.D., Senior Vice President, Preclinical Development at Marina Biotech, Inc., at Asia TIDES Oligonucleotides and Peptides® Research Technology and Product Development March 2 - 4, 2011 in Tokyo, Japan.

Malignant ascites, also known as malignancy-related ascites, is a condition in which fluid collects in the abdomen as a result of cancer. Ovarian and gastrointestinal cancers are the most common causes and patients with this condition have poor survival prognosis and limited treatment options. Local (intraperitoneal) administration of a Marina Biotech UsiRNA targeting polo-like kinase 1 (PLK1) formulated in a DiLA2-based delivery system resulted in up to 90% knockdown of PLK1 mRNA in ovarian cancer-derived tumor tissue demonstrating effective delivery to tumors within the abdominal cavity. The mechanism of action was confirmed to be mediated by RNA interference.

“These results further demonstrate the utility of our DiLA2 delivery technology for local administration,” stated Barry Polisky, PhD, Chief Scientific Officer at Marina Biotech, Inc. “As we look to expand our preclinical and clinical pipeline, malignant-related ascites is an ideal pipeline opportunity for us. This indication represents a significant patient population with very few therapeutic alternatives. We believe we can rapidly develop clinical candidates for IND-enabling studies should our preclinical efforts continue to demonstrate positive results.”

About Marina Biotech, Inc.

Marina Biotech is a biotechnology company, focused on the development and commercialization of RNA interference- (RNAi) and RNA-based therapeutics. The Marina Biotech pipeline currently includes a clinical program in Familial Adenomatous Polyposis (a precancerous syndrome) and two preclinical programs -- in hepatocellular carcinoma and bladder cancer. Marina Biotech has recently entered an exclusive agreement with Debiopharm Group for the development and commercialization of the bladder cancer program. Marina Biotech’s goal is to improve human health through the development of RNAi and RNA-based compounds and drug delivery technologies that together provide superior therapeutic options for patients. Additional information about Marina Biotech is available at http://www.marinabio.com.

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 Marina Biotech to obtain additional funding; (ii) the ability of Marina Biotech to attract and/or maintain manufacturing, research, development and commercialization partners; (iii) the ability of Marina Biotech and/or a partner to successfully complete product research and development, including preclinical and clinical studies and commercialization; (iv) the ability of Marina Biotech and/or a partner to obtain required governmental approvals; and (v) the ability of Marina Biotech 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 Marina Biotech’s most recent periodic reports on Form 10-K and Form 10-Q that are filed with the Securities and Exchange Commission. Marina Biotech assumes no obligation to update and supplement forward-looking statements because of subsequent events.