UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): October 19, 2020

Assembly Biosciences, Inc.

(Exact name of Registrant as Specified in Its Charter)

Registrant’s Telephone Number, Including Area Code: (833) 509-4583

Not Applicable

(Former Name or Former Address, if Changed Since Last Report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

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

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

Emerging growth company ☐

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. ☐

Item 5.02 Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers.

On October 19, 2020, the Board of Directors (the “Board”) of Assembly Biosciences, Inc. (the “Company”) increased the size of the Board from eight directors to nine directors and appointed Gina Consylman as an independent, nonemployee member of the Board to fill the resulting vacancy, effective immediately. Ms. Consylman was also appointed a member of the Audit Committee.

Ms. Consylman will participate in the standard independent, nonemployee director compensation arrangements described in the proxy statement for the Company’s 2020 annual meeting of stockholders under the caption entitled “Director Compensation.” In addition, in connection with her appointment to the Board, Ms. Consylman was granted options to purchase 20,000 shares of the Company’s common stock, which will vest in three approximately equal annual installments on the first, second and third anniversaries of the grant date, subject to Ms. Consylman’s continuous service on each vesting date.

There are no arrangements or understandings between Ms. Consylman and any other person pursuant to which she was selected to serve on the Board, and there are no relationships between Ms. Conyslman and the Company that would require disclosure under Item 404(a) of Regulation S-K.

A copy of the Company’s press release announcing Ms. Consylman’s appointment to the Board is attached as Exhibit 99.1 to this Current Report on Form 8-K and is incorporated herein by reference.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits.

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SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

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