8-K

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):January 4, 2023

SERES THERAPEUTICS, INC.

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code: (617) 945-9626

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. ☐

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

On January 4, 2023, the Board of Directors (the “Board”) of Seres Therapeutics, Inc. (the “Company”) increased its size to provide for a total of ten directors authorized to serve on the Board and appointed Claire Fraser, Ph.D. as a Class II director of the Company. Dr. Fraser has been appointed to serve on the Audit Committee of the Board (the “Audit Committee”).

Dr. Fraser will participate in the Company’s standard compensation program for non-employee directors, including an annual retainer of $45,000, an annual retainer for service on the Audit Committee of $10,000 and an initial award of an option to purchase 48,000 shares of the Company’s common stock (the “Initial Award”). The Initial Award has an exercise price equal to $5.47, the closing price per share of the Company’s common stock on the date of grant, and will vest and become exercisable in equal installments on each of the first four anniversaries of the date of grant or in full immediately prior to the occurrence of a change in control, subject to continued service on the Board through each such vesting date.

Dr. Fraser has also entered into the Company’s standard indemnification agreement for directors and officers.

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 hereunto duly authorized.