smmt-20260805 0001599298 FALSE 0001599298 2026-08-05 2026-08-05

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): August 5, 2026
 

Summit Therapeutics Inc.
(Exact Name of Registrant as Specified in Its Charter)

Delaware 001-36866 37-1979717
(State or Other Jurisdiction
of Incorporation) (Commission
File Number) (IRS Employer
Identification No.)

601 Brickell Key Drive, Suite 1000 , Miami , FL
33131
(Address of Principal Executive Offices) (Zip Code)

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

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):
 
☐ 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:

Title of Each Class Trading Symbol(s) Name of Each Exchange on Which Registered
Common stock, $0.01 par value per share SMMT The Nasdaq Stock Market LLC

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 8.01
Other Events.

On August 5, 2026, Summit Therapeutics Inc. issued a press release announcing the expansion of its global registration-enabling clinical development program for ivonescimab into urothelial carcinoma, or bladder cancer, with the planned initiation of the global, multi-regional Phase II/III HARMONi-GU1 trial (“HARMONi-GU1”). HARMONi-GU1 will evaluate ivonescimab plus the antibody-drug conjugate enfortumab vedotin (“EV”) compared to pembrolizumab plus EV as first-line therapy in patients with previously untreated locally advanced or metastatic urothelial carcinoma. Global clinical trial site activations for HARMONi-GU1 will begin later this year.

A copy of the press release is attached as Exhibit 99.1 to this Current Report on Form 8-K and is incorporated by reference herein.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits

Exhibit Number
Description
99.1 Press Release, dated August 5, 2026

104 Cover Page Interactive Data File (embedded within the Inline XBRL document)

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.

SUMMIT THERAPEUTICS INC.

Date: August 5, 2026 By: /s/ Manmeet S. Soni
Chief Operating Officer, Chief Financial Officer and Director
(Principal Financial Officer)