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): April 1, 2020

KALEIDO BIOSCIENCES, INC.

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code: (617) 674-9000

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 (see General Instruction A.2. below):

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. ☐

Appointment of New Director

On April 1, 2020, upon the recommendation of its Nominating and Corporate Governance Committee, the Board of Directors (the “Board”) of Kaleido Biosciences, Inc. (the “Company”) appointed Anne Prener to join the Board, effective as of April 1, 2020. The Board determined that Dr. Prener is independent under the listing standards of Nasdaq and the Company’s corporate governance guidelines. Dr. Prener will serve as a Class III director with a term expiring at the annual meeting of stockholders to be held in 2022. Dr. Prener was also appointed to serve on the Nominating and Corporate Governance Committee of the Board. Effective as of April 1, 2020, the Nominating and Corporate Governance Committee of the Board will be composed of Dr. Prener, Bonnie Bassler and Grady Burnett and the composition of the Audit Committee and the Compensation Committee both remain unchanged.

As a non-employee director, Dr. Prener will receive cash compensation and an equity award for her Board service in accordance with the Company’s non-employee director compensation policy. Dr. Prener is not a party to any transaction with the Company that would require disclosure under Item 404(a) of Regulation S-K, and there are no arrangements or understandings between Dr. Prener and any other persons pursuant to which she was selected as a director. In addition, Dr. Prener will enter into an indemnification agreement with the Company consistent with the form of indemnification agreement entered into between the Company and its existing non-employee directors.

On April 3, 2020, the Company issued a press release announcing the changes to the composition of its Board. A copy of this press release is furnished as Exhibit 99.1 to this report on Form 8-K.

SIGNATURE

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 hereunto duly authorized.