Marina Biotech Announces That Licensee Mirna Therapeutics Enrolls First Patient in Hematologic Malignancy Cohort of On-Going Trial

BOSTON, MA--(Marketwired - Jun 12, 2014) - Marina Biotech, Inc. (PINKSHEETS: MRNA), a leading nucleic acid-based drug discovery and development company focused on rare diseases, today announced that the Company's licensee, Mirna Therapeutics, has reported that Mirna enrolled the first patient in the hematological malignancy cohort of its ongoing Phase 1 clinical trial of MRX34. MRX34 is Mirna's lead product candidate and first microRNA mimic in human clinical trials in the oncology space. Under terms of the license agreement, Mirna has full responsibility for the development and commercialization of any products which arise during the license period, and Marina Biotech could receive up to $60 million in total upfront, clinical and commercialization milestone payments, as well as royalties on sales, based on the successful outcome of the collaboration.

"We are pleased to see MRX34's progress in the clinic and look forward to getting further patient experience with our enabling SMARTICLES delivery technology," stated J. Michael French, President and CEO at Marina Biotech. "Currently, we believe Marina is the only company with a technology in development that is delivering both a single-stranded and double-stranded oligonucleotide in Phase 1 and Phase 2 clinical trials. As Mirna continues to pioneer microRNA-based Replacement Therapy to treat cancers, we look forward to the advancement of this program, the validation of this novel mechanism of action and further validation of Marina's oligonucleotide delivery platform."

The multicenter, open-label Phase 1 clinical trial of MRX34 was initiated in April 2013 and is currently enrolling patients with unresectable primary liver cancer or solid cancers with liver involvement. The trial is currently enrolling a separate cohort of patients with hematological malignancies, which are cancers that affect blood, bone marrow and lymph nodes and may include non-Hodgkin's lymphoma, acute myelogenous leukemia, acute and chronic lymphocytic leukemia, chronic myelogenous leukemia in accelerated or blast phase, multiple myeloma or myelodysplastic syndrome.

An interim analysis of safety data from the first 26 patients was recently presented at the American Association of Clinical Research (AACR) annual meeting. The interim data showed that the most common adverse events associated with MRX34 in the patients studied have been manageable with standard interventions used by oncologists, with one incident of a dose-limiting toxicity observed. The maximum tolerated dose had not been reached and additional patients are being enrolled into the study.

The Phase 1 clinical trial design consists of an initial dose-escalation phase, followed by an expansion phase after a recommended Phase 2 dose has been identified. In the liver-based cancer cohort, which aims to enroll approximately 48 patients, MRX34 is administered intravenously twice a week for three weeks with one week off, during 28-day cycles, until disease progression or intolerance. In the hematologcal malignancy cohort, which aims to enroll approximately 15 patients, patients will be treated continuously for five days with MRX34, followed by two weeks off, during 21-day cycles, until disease progression or intolerance. The primary objectives of both clinical trial cohorts are to establish the maximum tolerated dose and the recommended Phase 2 dose for future clinical trials. The secondary objectives are to assess the safety, tolerability and pharmacokinetic profile of MRX34 after intravenous dosing as well as to assess biological and clinical activity. Additional information on the Phase 1 clinical trial and enrollment can be found at clinicaltrials.gov (http://clinicaltrials.gov/ct2/show/NCT01829971).

About Mirna Therapeutics, Inc.'s MRX34
MRX34, a first in class cancer therapy, was designed to deliver a mimic of the naturally occurring microRNA tumor suppressor, miR-34, which is under expressed in tumors of patients with a wide variety of cancers, including cervical cancer, ovarian cancer, glioblastoma, hepatocellular carcinoma (liver cancer), colon cancer and non-small cell lung cancer, and in cancer stem cells. The miR-34 mimic is encapsulated using an innovative liposomal formulation called SMARTICLES®, which Mirna has licensed from Marina Biotech. Mirna filed its first Investigational New Drug (IND) Application with the U.S. Food and Drug Administration (FDA) for MRX34 in early 2013 and initiated the ongoing Phase 1 clinical trial in April 2013, making MRX34 the first microRNA Replacement Therapy product candidate to enter a clinical trial in cancer. This clinical trial is supported in part by a commercialization grant from the Cancer Prevention and Research Institute of Texas (CPRIT). Additional information on the Phase 1 clinical trial and enrollment can be found at clinicaltrials.gov (http://clinicaltrials.gov/ct2/show/NCT01829971).

About SMARTICLES Clinical Experience.
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. These achievements represent the combined preclinical and clinical experiences (a total of approximately 50 patients) of licensees ProNAi Therapeutics, Inc., Plymouth, MI and Mirna Therapeutics, Inc., Austin, TX. ProNAi Therapeutics' clinical compound, PNT2258, is a first-in-class, 24-base, single-stranded, chemically-unmodified DNA oligonucleotide drug targeting BCL2. 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.

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.