SMMT notes ivonescimab OS gain to 16.8 months in HARMONi-A

Rhea-AI Filing Summary

Summit Therapeutics (SMMT) reported that its partner Akeso published final overall survival results from the Phase III HARMONi-A trial in China. The study tested ivonescimab plus platinum-doublet chemotherapy versus chemotherapy alone in EGFR‑mutated, locally advanced or metastatic non-squamous NSCLC after EGFR TKI therapy.

Ivonescimab plus chemotherapy achieved a statistically significant and clinically meaningful overall survival benefit with a hazard ratio of 0.74 (95% CI: 0.58, 0.95; p=0.019). Median OS was 16.8 months (95% CI: 14.5, 20.0) versus 14.1 months (95% CI: 12.8, 16.3) for chemotherapy alone. The analysis used an April 2025 data cut-off and had a 32.5‑month median follow-up. Summit furnished these data via a press release attached as Exhibit 99.1.

Insights

Oncology clinical trials analyst

Phase III shows statistically significant OS benefit (HR 0.74).

Akeso reported the final overall survival analysis from HARMONi-A in EGFR‑mutated NSCLC after prior EGFR TKI therapy. Ivonescimab plus chemotherapy reduced the risk of death versus chemotherapy alone with a hazard ratio of 0.74 (95% CI: 0.58, 0.95; p=0.019). Median OS improved to 16.8 months versus 14.1 months.

The result is labeled both statistically significant and clinically meaningful in the disclosure, supported by a mature dataset (data cut-off April 2025, median follow-up 32.5 months). Actual implications for Summit depend on partnership scope and subsequent steps, which are not detailed in this excerpt.

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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): November 7, 2025

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 November 7, 2025, Summit Therapeutics Inc. (the “Company”) issued a press release noting that its partner, Akeso, Inc., (“Akeso”) published results from the Phase III HARMONi-A trial (“HARMONi-A”), conducted in China and sponsored by Akeso, which evaluated ivonescimab combined with platinum-doublet chemotherapy in patients with epidermal growth factor receptor (“EGFR”)-mutated, locally advanced or metastatic non-squamous non-small cell lung cancer who have progressed after treatment with an EGFR tyrosine kinase inhibitor against placebo plus platinum-doublet chemotherapy.

In the only planned and final overall survival (“OS”) analysis of HARMONi-A, ivonescimab plus chemotherapy demonstrated a statistically significant and clinically meaningful improvement when compared with chemotherapy alone, achieving a hazard ratio of 0.74 (95% CI: 0.58, 0.95, p=0.019). Median OS was 16.8 months (95% CI: 14.5, 20.0) in patients treated with ivonescimab plus chemotherapy compared to 14.1 months (95% CI: 12.8, 16.3) for those treated with chemotherapy alone. The data cut-off for this analysis was April 2025 with a median follow-up time of 32.5 months.

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 November 7, 2025
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: November 7, 2025			By:			/s/ Manmeet S. Soni
						Chief Operating Officer, Chief Financial Officer and Director
						(Principal Financial Officer)