BOTHELL, WA--(Marketwire - Dec 4, 2012) - Marina Biotech, Inc. (PINKSHEETS: [ MRNA ]), a leading nucleic acid-based drug discovery and development company, today announced that the U.S. Patent and Trademark Office (USPTO) has issued United States Patent 8,314,227. The patent expands protection to the Company's Unlocked Nucleobase Analog (UNA) modification and substitution chemistry. The claims of this patent broadly cover the use of a UNA in a number of RNA-based oligonucleotides including an RNA duplex, a microRNA mimic, a microRNA antagonist, and an RNA-binding RNA steric blocker. In addition, the RNA duplex may be either a RISC- or Dicer-length small interfering RNA (siRNA) and have a discontinuous passenger strand.

"We are pleased to see that the USPTO recognizes the significance of our UNA chemistry for the development of oligonucleotide therapeutics," stated J. Michael French, President and Chief Executive Officer at Marina Biotech. "This is a key and important patent issuance for the Company as it provides us and our licensees the freedom to pursue the broad use of UNA-containing oligonucleotides for therapeutic uses. Specifically, we can pursue a multitude of single and double-stranded RNA-based oligonucleotide compounds with a wide variation in length. We believe these claims put to rest issues of so called 'blocking IP' in the RNA interference (RNAi) and microRNA sectors. More importantly, we have demonstrated that UNA has the potential to improve RNAi therapeutics by increasing stability and reducing sense and antisense mediated off-target effects while retaining potency. Our recent license agreement with Tekmira Pharmaceuticals attests to the value of this technology and we look forward to continuing to exploit this key asset."

Unlocked Nucleobase Analogs (UNA) are acyclic ribonucleoside analogs in which the bond between C2' and C3' atoms is broken. This change in sugar structure renders this nucleoside analog very flexible. This characteristic is in sharp contrast to the widely used locked nucleosides that lock the sugar conformation by a bridged bond between C2' and C4' atoms. The flexible nature of UNA reduces the binding affinity between two strands of an RNAi drug and gives unique characteristics to its gene silencing abilities.

About Marina Biotech, Inc.

Marina Biotech is a biotechnology company focused on the development and commercialization of oligonucleotide-based therapeutics utilizing multiple mechanisms of action including RNA interference (RNAi) and messenger RNA translational blocking. The Marina Biotech pipeline currently includes a clinical program in Familial Adenomatous Polyposis (a precancerous syndrome) and two preclinical programs -- in bladder cancer and myotonic dystrophy. Marina Biotech has entered into an agreement with both Mirna Therapeutics and ProNAi Therapeutics to license Marina Biotech's SMARTICLES® technology for the delivery of microRNA mimics and DNAi, respectively. In addition, Marina Biotech announced exclusive licensing agreements with Monsanto Company for Marina Biotech's delivery and chemistry technologies and with Girindus America for the supply of CRN-based oligonucleotides. Marina Biotech recently entered into non-exclusive agreements with Novartis Institutes for Biomedical Research and Tekmira Pharmaceuticals to license Marina Biotech's CRN and UNA nucleic acid modification chemistries, respectively. Marina Biotech's goal is to improve human health through the development of RNAi- and oligonucleotide-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 in the near term; (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 prior to, and 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.