Marina Biotech Reports That Partner Mirna Therapeutics Presented Interim Phase 1 Data on Its First-in-Class microRNA-34 Mimic

BOTHELL, WA--(Marketwired - Nov 20, 2014) - Marina Biotech, Inc. (OTCQB: MRNA), a leading nucleic acid-based drug discovery and development company focused on rare diseases, today reported that its partner, Mirna Therapeutics, presented interim safety and preliminary efficacy data from a multicenter, open-label Phase 1 clinical trial of MRX34. MRX34 is a microRNA34 mimic formulated in the Company's SMARTICLES^® delivery technology. The data show that MRX34 has a manageable safety profile in patients with advanced primary liver cancer (hepatocellular carcinoma), other solid tumors with liver metastasis, and hematological malignancies. A maximum tolerated dose (MTD) was established at 110 mg/m² for MRX34 administered twice weekly for three weeks followed by one week off. Dose escalation is on-going for a second dosing regimen wherein MRX34 is administered daily for five consecutive days followed by two weeks off. While this Phase 1 study is intended to investigate safety, tolerability, pharmacokinetics, and dosing regimens, treatment with MRX34 has provided early signals of clinical activity in advanced cancer patients with primary liver, neuroendocrine, colorectal and small cell lung cancers, as well as diffuse large B-cell lymphoma.

The findings were presented yesterday by Dr. Muhammad Shaalan Beg, Assistant Professor of Internal Medicine and co-leader of the gastro-intestinal oncology group at University of Texas Southwestern Harold C. Simmons Cancer Center in Dallas, Texas, at the 26^th EORTC-NCI-AACR Symposium on Molecular Targets and Cancer Therapeutics hosted by the European Organisation for Research and Treatment of Cancer (EORTC), the National Cancer Institute (NCI), and the American Association for Cancer (AACR) taking place in Barcelona, Spain from November 18-21, 2014.

"We are very pleased with Mirna Therapeutics' progress in developing this first-in-class microRNA mimic," stated J. Michael French, president and Chief Executive Officer of Marina Biotech. "Thus far nearly 100 patients have been dosed with a SMARTICLES formulated oligonucleotide. We believe SMARTICLES is emerging as one of the most versatile technologies in the sector delivering both single and double-stranded oligonucleotides to two different cell compartments (nucleus and cytoplasm) and to tissue systems outside the liver. We look forward to the continued success of the Mirna team and the advancement of MRX34 in the treatment of multiple cancers."

About Mirna Therapeutic's Phase 1 Trial
The Phase 1 MRX34 study design consists of an initial dose-escalation phase, followed by an expansion phase in one or more focused cancer types. In the study, MRX34 is administered intravenously (IV) to patients in one of two dosing schedules, either twice a week for three weeks with one week off, during 28-day cycles or daily for five days with two weeks off, in 21-day cycles, until disease progression or intolerance. Dose escalation in the daily times five dosing schedule is currently ongoing. The primary objectives of the clinical trial 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 IV dosing as well as to assess pharmacodynamics and clinical activity of MRX34. Clinical activity is assessed by tumor response using RECIST, modified RECIST (primary liver cancer), or other cancer-specific criteria (hematologic malignancies) and evaluated by Computed Tomography/Magnetic Resonance Imaging (CT/MRI), Positron Emission Tomography/ Computed Tomography (PET/CT), or other standard methods every six to eight weeks. The study is being conducted at leading cancer research centers in the U.S. and Korea.

Data from 52 patients are included in the interim analysis, which showed that treatment emergent adverse events primarily consisted of infusion reactions such as fever, chills, nausea, vomiting, back and flank pain. The addition of dexamethasone, a corticosteroid, as premedication was found to ameliorate infusion reactions. Other treatment emergent adverse events included fatigue, diarrhea, headache, dehydration, elevation of liver enzymes, decreased albumin, hyponatremia, lymphopenia, thrombocytopenia, and neutropenia.

About MRX34
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. 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. MRX34 is delivered using the SMARTICLES^® liposomal delivery formulation, in-licensed from Marina Biotech.

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.