MIRAGEN THERAPEUTICS REPORTS FOURTH QUARTER AND FULL YEAR 2017 FINANCIAL RESULTS AND PROVIDES CORPORATE UPDATE Data from Phase 1 clinical trial supports advancing cobomarsen, or MRG-106, into a Phase 2 potentially regist

MIRAGEN THERAPEUTICS REPORTS FOURTH QUARTER AND FULL YEAR 2017 FINANCIAL RESULTS AND PROVIDES CORPORATE

BOULDER, CO, March 14, 2018 (GLOBE NEWSWIRE)

miRagen Therapeutics, Inc. (NASDAQ: MGEN), a clinical-stage biopharmaceutical company focused on the discovery and development of RNA-targeted therapies, today reported fourth quarter and full year 2017 financial results and provided a corporate

2017 was a remarkable year for miRagen, underscored by the clinical success and advancement of our two lead programs, cobomarsen (MRG-106) and MRG-201, and we believe we are well-positioned to make advances in the development of our product candidates in 2018, said miRagen President and Chief

Executive Officer William S. Marshall, Ph.D. The cobomarsen Phase 1 results have been encouraging, and we plan to initiate a Phase 2 clinical trial to evaluate cobomarsen in cutaneous T-cell Lymphoma

(CTCL) this year. We have designed this trial to allow the possibility of accelerated approval in the United States, subject to the outcome of the trial. In 2018, we expect to initiate four clinical trials, including the Phase 2 SOLAR trial

evaluating cobomarsen in CTCL, a Phase 2 trial for MRG-201 in cutaneous fibrosis and two Phase 1 trials in collaboration with Servier for MRG-110 to support development

in ischemic diseases. Additionally, in 2018 we expect to report interim data from our Phase 1 trial evaluating cobomarsen in multiple hematological malignancies beyond CTCL.

Business Highlights and Update

miRagen intends to initiate a Phase 2 clinical trial for cobomarsen in patients with CTCL in the

second half of 2018. Based on recent meetings with the U.S. Food and Drug Administration, miRagen anticipates the trial will employ an open-label, parallel group, randomized design to evaluate the safety and efficacy of 300 mg of cobomarsen given by

intravenous infusion versus an active control.

The Company also began evaluating cobomarsen in three additional oncology indications

within the current Phase 1 trial. These additional indications include chronic lymphocytic leukemia, diffuse large B-cell lymphoma, and adult T-cell leukemia/lymphoma.

In each of these expansion indications, the disease process appears to correlate with an increase in microRNA-155 levels. The Company plans to release interim Phase 1 data in at least one of these expansion

indications in the second half of 2018.

anticipates releasing preclinical in vivo data from lung and ocular fibrosis studies in 2018.

Also, during the first half of 2018, miRagen plans to initiate a separate Phase 1 trial assessing the safety and tolerability of MRG-110 after intradermal administration in healthy volunteers . The intradermal administration clinical trial is intended to support additional clinical studies necessary to achieve regulatory approval for the use

of MRG-110 in other diseases, including dermatological applications, where increased vascularity may result in better healing and improved outcomes.

Servier is responsible for leading the global clinical development and potential commercialization of

MRG-110 in all countries except the United States and Japan, where miRagen retains all rights.

Anticipated Milestones

Conference Call Information

miRagen will host a conference call today at 4:30 p.m. ET to discuss its financial results for the fourth quarter and full year 2017. Participants may access

the call by dialing (800) 289-0438 in the U.S. or (323) 994-2083 outside the U.S. and providing the conference ID number 5740056. The call will also be webcast and can

be accessed from the Investors and Media section of the Company s website at www.miragen.com. A replay of this conference call will be available on miRagen s website approximately one hour after the event.

About miRagen Therapeutics, Inc.

miRagen Therapeutics,

Inc. is a clinical-stage biopharmaceutical company discovering and developing proprietary RNA-targeted therapies with a specific focus on microRNAs and their role in diseases where there is a high unmet

medical need. miRagen s two lead product candidates, cobomarsen (MRG-106) and MRG-201, are currently in clinical development. miRagen s clinical product

candidate for the treatment of certain cancers, cobomarsen (MRG-106), is an inhibitor of microRNA-155, which is found at abnormally high levels in malignant cells of

several blood cancers, as well as certain cells involved in inflammation. miRagen s clinical product candidate for the treatment of pathological fibrosis, MRG-201 is a replacement for microRNA-29, which is found at abnormally low levels in a number of pathological fibrotic conditions, including cutaneous, cardiac, renal, hepatic, pulmonary and ocular fibrosis, as well as systemic sclerosis.

miRagen is also developing MRG-110, an inhibitor of microRNA-92, under a license and collaboration agreement with Servier.

MRG-110 is being developed for the treatment of heart failure and other ischemic diseases. In addition to these programs, miRagen is developing a pipeline of preclinical product candidates. The goal of

miRagen s translational medicine strategy is to progress rapidly to first-in-human studies once it has established the pharmacokinetics, pharmacodynamic, safety and

manufacturability of the product candidate in preclinical studies. For more information, please visit www.miragen.com.

For information on clinical

trials please visit www.clinicaltrials.gov.

Note Regarding Forward-Looking Statements

This press release may contain forward-looking statements that involve substantial risks and uncertainties for purposes of the safe harbor provided by the

Private Securities Litigation Reform Act of 1995. All statements contained in this press release other than statements of historical fact, including statements regarding miRagen s strategy, future operations, future financial position, future

revenue, projected expenses, prospects, plans and objectives of management or the expected features of or potential indications for miRagen s product candidates are forward-looking statements. The words believe, may,

will, estimate, continue, anticipate, intend, plan, expect, predict, potential, opportunity, goals, or

should, and similar expressions are intended to

identify forward-looking statements. Such statements are based on management s current expectations and involve risks and uncertainties. Actual results and performance could differ

materially from those projected in the forward-looking statements as a result of many factors, including, without limitation: that miRagen has incurred losses since its inception, and anticipates that it will continue to incur significant losses for

the foreseeable future, and as a result miRagen cannot guarantee that it will be able to start, or cause its clinical trials to progress, on the schedule it currently anticipates; future financing activities may cause miRagen to restrict its

operations or require it to relinquish rights; miRagen may fail to demonstrate safety and efficacy of its product candidates; miRagen s product candidates are unproven and may never lead to marketable products; miRagen s product candidates

are based on a relatively novel technology, which makes it difficult to predict the time and cost of development and of subsequently obtaining regulatory approval, if at all; miRagen s product candidates may cause undesirable side effects or

have other properties that could delay or prevent the regulatory approval; and results of miRagen s Phase 1 clinical trials are not sufficient to show safety and efficacy of miRagen s product candidates and may not be indicative of future

clinical trial results.

miRagen has based these forward-looking statements largely on its current expectations and projections about future events and

trends. These forward-looking statements are subject to a number of risks, uncertainties and assumptions, including those described under the heading Risk Factors in miRagen s Annual Report on Form

10-K and subsequent periodic reports filed with the Securities and Exchange Commission. Moreover, miRagen operates in a very competitive and rapidly changing environment. New risks emerge from time to time. It

is not possible for its management to predict all risks, nor can it assess the impact of all factors on its business or the extent to which any factor, or combination of factors, may cause actual results to differ materially from those contained in

any forward-looking statements it may make. In light of these risks, uncertainties and assumptions, the future events and trends discussed in this press release may not occur and actual results could differ materially and adversely from those

anticipated or implied in the forward-looking statements. miRagen undertakes no obligation to revise or publicly release the results of any revision to such forward-looking statements, except as required by law. Given these risks and uncertainties,

readers are cautioned not to place undue reliance on such forward-looking statements. All forward-looking statements are qualified in their entirety by this cautionary statement.

Investor/Media Contact:

Chief Business Officer

Miragen Therapeutics, Inc.

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Miragen Therapeutics, Inc.

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