UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K/A

(Amendment No. 1)

(Mark One)

For the fiscal year ended December 31, 2017

or

For the transition period from                      to                     

Commission File No. 001-36483

MIRAGEN THERAPEUTICS, INC.

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code: (720) 643-5200

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act: None

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.    Yes  ☐    No  ☒

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Exchange Act.    Yes  ☐    No  ☒

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.    Yes  ☒    No  ☐

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).    Yes  ☒    No  ☐

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein, and will not be contained, to the best of registrant’s knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K.  ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.  ☐

Indicate by check mark whether the registrant is shell company (as defined in Rule 12b-2 of the Exchange Act). Yes  ☐    No  ☒

The aggregate market value of the voting stock held by non-affiliates of the registrant, based upon the closing sale price of the registrant’s Common Stock on June 30, 2017 as reported on The Nasdaq Capital Market, was $122.4 million. Shares of Common Stock held by each executive officer and director and by each person who owns 10% or more of the outstanding Common Stock have been excluded in that such persons may be deemed to be affiliates. This determination of affiliate status is not necessarily a conclusive determination for other purposes.

As of April 18, 2018, there were 30,192,373 shares of the registrant’s Common Stock outstanding.

EXPLANATORY NOTE

This Amendment No. 1 on Form 10-K/A, or Amendment No. 1, amends the Annual Report on Form 10-K, or the Annual Report, of Miragen Therapeutics, Inc., or the Company, for the year ended December 31, 2017, as filed by the Company on March 15, 2018. This Amendment No. 1 hereby amends Part III, Item 11 of the Annual Report solely to add the information regarding director compensation included below. In addition, we are also including Exhibits 31.1, 31.2 and 32.1 required by the filing of this Amendment No. 1.

Except as otherwise stated herein, no other information contained in the Annual Report has been updated by this Amendment No. 1, and the Company has not updated the disclosures contained therein to reflect any events that occurred subsequent to the date of the Annual Report. Accordingly, this Amendment No. 1 should be read in conjunction with the Annual Report and the Company’s filings made with the U.S. Securities and Exchange Commission subsequent to the filing of the Annual Report. The filing of this Amendment No. 1 is not an admission that the Annual Report, when originally filed, included any untrue statement of a material fact or omitted to state a material fact necessary to make a statement not misleading. Unless context requires otherwise, references in this Amendment No. 1 to “Miragen,” “the Company,” “we,” “us” and “our” refer to Miragen Therapeutics, Inc.

PART III

ITEM 11. EXECUTIVE COMPENSATION

2017 Director Compensation

The table below sets forth the compensation of our non-employee directors for the fiscal year ended December 31, 2017.

Arlene Morris is not included in the table above, because she did not become a member of our board of directors until January 2018.

PART IV

ITEM 15. EXHIBITS AND FINANCIAL STATEMENT SCHEDULES

SIGNATURES

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the registrant has duly caused this Amendment No. 1 to the Annual Report to be signed on its behalf by the undersigned, thereunto duly authorized.

Pursuant to the requirements of the Securities Exchange Act of l934, this Amendment No. 1 to the Annual Report has been signed by the following persons on behalf of the registrant and in the capacities and on the dates indicated.