Marina Biotech Presents Clinical Data Demonstrating Delivery of Both Single and Double-Stranded Nucleic Acids to Tumors

BOSTON, MA--(Marketwired - May 6, 2014) - Marina Biotech, Inc. (PINKSHEETS: MRNA), a leading nucleic acid-based drug discovery and development company focused on rare diseases, presented data from preclinical and clinical programs utilizing the Company's SMARTICLES delivery technology. To date, SMARTICLES-delivered nucleic acid drug candidates have demonstrated: delivery to tumor in Phase 1 and 2 clinical trials; statistically significant, dose-dependent, and specific knockdown of a gene target in a Phase 1 clinical trial; single agent anti-tumor activity in patients with recurrent or refractory non-Hodgkin's lymphoma (NHL) in a Phase 2 clinical trial; and anti-tumor efficacy with both single- and double-stranded oligonucleotides in rodent models.

The data, in approximately 50 patients to date, were presented yesterday at the Therapeutics Discovery Symposia - 2014 in Waltham, MA during the RNAi, MicroRNA and Stem Cell track by J. Michael French, CEO of Marina Biotech. The data was provided by, and represents the combined preclinical and clinical experiences of, licensees ProNAi Therapeutics, Inc., Plymouth, MI and Mirna Therapeutics, Inc., Austin, TX.

"The combined clinical delivery experiences of ProNAi and Mirna is impressive," stated J. Michael French, President and CEO of Marina Biotech. "We believe that SMARTICLES, which is broadly covered by the Company's patent estate, is the only delivery technology in clinical development that is delivering both a single- and a double-stranded nucleic acid. The versatility of this novel delivery technology is one of the cornerstones of the Company's broad nucleic acid drug discovery platform as well as a potential key capability and product differentiator in the further development of our rare disease clinical pipeline. We are pleased to see the success of the ProNAi and Mirna clinical efforts as well as their ability to raise, to date, a combined $100 MM in financing to advance their clinical programs."

ProNAi Therapeutics' clinical compound, PNT2258, is a first-in-class, 24-base, single-stranded, chemically-unmodified DNA oligonucleotide drug targeting BCL2. PNT2258 exhibits single agent anti-tumor activity in patients with recurrent or refractory NHL. Eighty-two percent of patients had tumor shrinkage when receiving single-agent therapy with PNT2258. To date, overall response rate in patients with follicular lymphoma (FL) is 40 percent and in patients with diffuse large B-cell lymphoma (DLBCL) overall response is 50 percent. PNT2258 is safe at a dose of 120 mg/m² administered intravenously for 2 to 3 hours on days 1 through 5 of a 21-day schedule. No tumor lysis syndrome or major organ toxicities were observed. No occurrences of elevated liver enzymes, hyperkalemia, hyperphosphatemia, hypocalcemia, renal failure/dysfunction, or infections were noted nor were any Grade 4 toxicities. PNT2258 drug exposures levels (AUC) exceeded by at least four-fold that required for anti-tumor activity in xenograft studies of human tumors, consistent with the Phase 1 trial.

Mirna Therapeutics' clinical compound, MRX34, is a double-stranded microRNA "mimic" of the naturally occurring tumor suppressor miR-34, which inhibits cell cycle progression and induces cancer cell death. The Phase 1 MRX34 study, for the treatment of patients with unresectable primary liver cancer or solid cancers with liver involvement, is designed with an initial dose-escalation phase of approximately 30 patients, followed by an expansion phase of approximately 18 additional patients after the recommended Phase 2 dose has been identified. MRX34 is administered intravenously twice a week for three weeks with one week off, during 28-day cycles, until disease progression or intolerance. Interim safety data from the multicenter, open-label Phase 1 clinical trial of MRX34 showed that MRX34 has a manageable safety profile with only one incident of a dose-limiting toxicity observed to date.

About Marina Biotech, Inc.
Marina Biotech is an oligonucleotide therapeutics company with broad drug discovery technologies providing the ability to develop proprietary single and double-stranded nucleic acid therapeutics including siRNAs, microRNA mimics, antagomirs, and antisense compounds, including messengerRNA therapeutics. These technologies were built via a roll-up strategy to discover and develop different types of nucleic acid therapeutics in order to modulate (up or down) a specific protein(s) which is either being produced too much or too little thereby causing a particular disease. We believe that the Marina Biotech technologies have unique strengths as a drug discovery engine for the development of nucleic acid-based therapeutics for rare and orphan diseases. Further, we believe Marina Biotech is the only company in the sector that has a delivery technology in human clinical trials with differentiated classes of payloads, through licensees ProNAi Therapeutics and Mirna Therapeutics, delivering single-stranded and double-stranded nucleic acid payloads, respectively. Our novel chemistries and other delivery technologies have been validated through license agreements with Roche, Novartis, Monsanto, and Tekmira. The Marina Biotech pipeline currently includes a clinical program in Familial Adenomatous Polyposis (a precancerous syndrome) and a preclinical program in myotonic dystrophy. 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 www.marinabio.com.

Marina Biotech 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 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 filings with the Securities and Exchange Commission. Marina Biotech assumes no obligation to update or supplement forward-looking statements because of subsequent events.