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): June 12, 2025

Registrant’s Telephone Number, Including Area Code: (305) 203-2034

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):

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

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. ☐

On June 12, 2025, Summit Therapeutics Inc. (the “Company”) held its 2025 Annual Meeting of Stockholders (the “Annual Meeting”). The following matters were submitted to a vote of the Company’s stockholders at the Annual Meeting: (i) the election of nine directors to serve until the Company’s 2026 Annual Meeting of Stockholders and until their successors are duly elected and qualified; (ii) the ratification of the appointment of PricewaterhouseCoopers LLP as the Company’s independent registered public accounting firm for the fiscal year ending December 31, 2025; and (iii) a non-binding advisory vote to approve the compensation paid to the Company’s named executive officers.

Each of the matters submitted to a vote of the Company’s stockholders at the Annual Meeting was approved by the requisite vote of the Company’s stockholders in accordance with the recommendation of the Company’s Board of Directors. Set forth below is the number of votes cast for, against or withheld, as well as the number of abstentions and broker non-votes, as to each such matter, including a separate tabulation with respect to each nominee for director, as applicable:

Proposal 1

Election of Directors

.

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.