Summit Therapeutics Inc. (SMMT)

Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations.

The following discussion and analysis of our financial condition and results of operations should be read in conjunction with our unaudited condensed consolidated financial statements and related notes included herein and our audited consolidated financial statements and related notes for the year ended December 31, 2025 included in our Annual Report. Some of the information contained in this discussion and analysis or set forth elsewhere in this filing, including information with respect to our plans and strategy for our business, includes forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended, that involve risks and uncertainties. All statements other than statements relating to historical matters including statements to the effect that we “believe,” “expect,” “anticipate,” “plan,” “target,” “intend” and similar expressions should be considered forward-looking statements. As a result of many factors, including those factors set forth in the risks identified in the “Risk Factors” section of our other filings with the SEC, our actual results could differ materially from the results, performance or achievements expressed in or implied by these forward-looking statements.

Company Overview

Summit Therapeutics Inc. (“we,” “Summit” or the “Company”) is a biopharmaceutical company focused on the discovery, development, and commercialization of patient-, physician-, caregiver- and societal-friendly medicinal therapies intended to improve quality of life, increase potential duration of life, and resolve serious unmet medical needs. The Company’s pipeline of product candidates is designed with the goal to become the patient-friendly, new-era standard-of-care medicines, in the therapeutic area of oncology.

The Company’s current lead development candidate is ivonescimab, a novel, potential first-in-class bispecific antibody intending to combine the effects of immunotherapy via a blockade of PD-1 with the anti-angiogenesis effects of an anti-VEGF compound into a single molecule. On December 5, 2022, the Company entered into the License Agreement with Akeso pursuant to which the Company has in-licensed intellectual property rights related to ivonescimab (as amended, the “License Agreement”). Through the License Agreement, the Company obtained the rights to develop and commercialize ivonescimab in the United States, Canada, Europe, and Japan. The License Agreement and transaction closed in January 2023 following customary waiting periods. On June 3, 2024, the Company entered into the Second Amendment with Akeso to expand its territories covered under the License Agreement to also include Latin America, including Mexico and all countries in Central America and South America, the Middle East and Africa. The Company’s operations are focused on the development of ivonescimab and other future activities, as the Company determines.

The Company is developing ivonescimab in non-small cell lung cancer (“NSCLC”) and colorectal cancer (“CRC”), specifically conducting Phase III clinical trials in the following proposed indications:

(a) ivonescimab combined with chemotherapy in patients with epidermal growth factor receptor (“EGFR”)-mutated, locally advanced or metastatic non-squamous NSCLC who were previously treated with a third-generation EGFR tyrosine kinase inhibitor (“TKI”) (“HARMONi”);

(b) ivonescimab combined with chemotherapy in patients with first-line metastatic NSCLC (including separate statistical analyses planned for patients with squamous NSCLC and non-squamous NSCLC) (“HARMONi-3”);

(c) ivonescimab monotherapy in patients with first-line metastatic NSCLC whose tumors have high PD-L1 expression (“HARMONi-7”); and

(d) ivonescimab combined with chemotherapy in patients with first-line unresectable metastatic CRC (“HARMONi-GI3”).

In October 2024, the Company completed enrollment in its HARMONi clinical trial. In May 2025, we announced topline results from our multiregional, double-blinded, placebo-controlled, Phase III study HARMONi. At the prespecified primary data analysis, ivonescimab in combination with chemotherapy demonstrated a statistically significant improvement in progression free survival (“PFS”), the magnitude of which we believe to be clinically meaningful, with a hazard ratio of 0.52 (95% CI: 0.41 – 0.66; p0.00001) compared to placebo in combination with chemotherapy; median PFS was 6.8 months for

20

those patients receiving ivonescimab plus chemotherapy compared to 4.4 months for those receiving chemotherapy. PFS was assessed by blinded independent central radiology committee (“BICR”).

We believe the PFS hazard ratio that was observed in both Asian and western sub-populations to be clinically meaningful. The primary analysis demonstrated the consistency of the magnitude of the PFS benefit between patients randomized in Asian and western territories, as well as the consistency in a single-region study (“HARMONi-A”) with this multiregional study.

In a longer-term follow-up of PFS, which included all western patients and at least six months of follow-up time for all patients, ivonescimab plus chemotherapy demonstrated a consistent improvement in PFS with an observed HR of 0.57 (95% CI: 0.46 – 0.71). With the longer-term follow-up analysis, consistency of the magnitude of PFS benefit was demonstrated between patients randomized in Asia and western patients when measured by hazard ratio. This longer-term follow-up analysis of PFS was performed at the time of the primary overall survival (“OS”) analysis.

Ivonescimab in combination with chemotherapy showed a positive trend in OS in the primary analysis without achieving a statistically significant benefit with a hazard ratio of 0.79 (95% CI: 0.62 – 1.01; p=0.057). This trend provides further support for its use in EGFRm NSCLC after TKI therapy, a setting where high unmet need continues to exist with limited approved options in the United States and other western territories. Currently there are no FDA-approved regimens that have demonstrated a statistically significant OS benefit in this patient setting. Both Asian and North American patients demonstrated a positive trend in OS. The results of the primary analysis in this multiregional study were consistent with that of the single-region randomized Phase III HARMONi-A study, which demonstrated a statistically significant OS benefit with a hazard ratio of 0.74 in the primary OS analysis in a similar patient population.

In September 2025, an additional ad hoc OS analysis was performed for the HARMONi study, whereby the western patients were followed for a longer period of time (Asian patients were locked at the time of the primary analysis). In this analysis that included longer-term follow-up of western patients (median follow-up time of western patients of 13.7 months), a hazard ratio consistent with the primary analysis was observed with an improved nominal p-value (HR=0.78; 95% CI: 0.62 – 0.98; nominal p=0.0332). Median OS for this analysis remained the same in both arms as was observed in the primary analysis. Median OS in Western patients receiving ivonescimab was 17.0 months compared to 14.0 months for those receiving placebo (HR=0.84); median OS in North American patients, specifically, had not yet been reached in the ivonescimab arm compared to 14.0 months in the placebo arm (HR=0.70). The hazard ratios for Western patients in totality, as well as patients from the North American and European regions individually, improved from the primary OS analysis to the analysis with longer-term follow-up of Western patients. Consistent benefit was observed across pre-defined subgroups.

In July 2026, an updated analysis was conducted with a data cutoff date of June 2026 which analyzed OS when most western patients had discontinued treatment or completed two years of treatment. This analysis showed a consistent OS trend amongst western and Asian patients as western patients were followed for additional time on study reaching median follow-up of 23.2 months; Asian patients remained locked with a median follow-up time of 32.7 months from the primary analysis. A hazard ratio of 0.76 was observed for the full population; the 0.76 hazard ratio was observed in western patient subgroup, respectively, in this analysis. Ivonescimab continued to demonstrate an acceptable and manageable safety profile, that was consistent with previous Phase III data of ivonescimab plus chemotherapy with no additional safety signals noted. These OS results have been made available to the FDA, and more detailed data are intended to be presented at an upcoming medical conference.

Based on the results of the HARMONi clinical trial, we submitted a Biologics License Application (“BLA”) in the fourth quarter of 2025 to seek approval for ivonescimab plus chemotherapy for this proposed indication. After careful consideration of the safety and efficacy profile of the current FDA-approved options for patients in this setting, the positive results of the Phase III multiregional study, including regional consistency, as well as discussions with key opinion leaders and those physicians who have administered ivonescimab to patients in a clinical study setting, we believe that the safety and efficacy data generated in the HARMONi study demonstrates that the ivonescimab regimen offers a potential treatment option for patients impacted by EGFR-mutant NSCLC in this setting with a favorable benefit-risk profile despite the lack of a statistically significant OS benefit. Summit announced in January 2026 that the FDA accepted for filing the BLA seeking approval for ivonescimab in combination with chemotherapy for this proposed indication. The FDA provided a Prescription Drug User Fee Act (PDUFA) goal action date of November 14, 2026. The FDA noted that a statistically significant OS benefit is necessary to support marketing authorization in this setting and the PFS results from this study may not be sufficient to support marketing authorization.

21

HARMONi-3 study (NCT05899608) is a Phase III, multi-regional, potentially registration-enabling clinical trial for which we initiated sites in North America, China and Europe. The two primary endpoints for this study are PFS and OS, and the study compares ivonescimab plus platinum-based doublet chemotherapy versus pembrolizumab plus platinum-based doublet chemotherapy in first-line patients with metastatic squamous NSCLC and non-squamous NSCLC. Enrollment is ongoing in all regions for patients with non-squamous tumors.

In October 2025, the Company announced a protocol amendment to separate the statistical analysis of the primary endpoints by histology. Therefore, there will be separate analyses conducted to evaluate ivonescimab plus chemotherapy compared to pembrolizumab plus chemotherapy in patients with squamous NSCLC and in patients with non-squamous NSCLC.

In order to sufficiently power for both primary endpoints (PFS and OS) in both cohorts of this study, Summit plans to enroll approximately 600 patients with squamous NSCLC and 1,000 patients with non-squamous NSCLC.

As a result of having two separate intention-to-treat analyses within the HARMONi-3 study, the analyses for squamous tumors and non-squamous tumors may be conducted at separate times, as each analysis will be conducted upon the prespecified numbers of events being reached in the separate cohorts.

Patient enrollment was completed for the squamous cohort of HARMONi-3 in the first quarter of 2026. Previously, Summit announced its intention to perform an interim PFS analysis for the squamous cohort of the HARMONi-3 study in the second quarter of 2026. To achieve statistical significance, there was a meaningfully higher bar than the upcoming planned final PFS analysis based on the minimal alph

[Excerpt truncated for page length; source filing is linked above.]

Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations

The following discussion and analysis of our financial condition and results of operations is for the year ended December 31, 2025 compared with the year ended December 31, 2024. This comparison should be read in conjunction with our consolidated financial statements and related notes appearing elsewhere in this Annual Report on Form 10-K. This discussion contains forward-looking statements based upon current expectations that involve risks and uncertainties. Our actual results may differ materially from those anticipated in these forward-looking statements as a result of various factors, including those set forth under “Risk Factors” included in Part I, Item 1A or in other parts of this Annual Report on Form 10-K. For a discussion and analysis of our financial condition and results of operations for the year ended December 31, 2024 compared to December 31, 2023, see Part II, Item 7, “Management’s Discussion and Analysis of Financial Condition and Results of Operations” included in the 2024 Annual Report on Form 10-K, filed with the Securities and Exchange Commission on February 24, 2025.

The Management’s Discussion and Analysis of Financial Condition and Results of Operations, or MD&A, describes principal factors affecting the results of our operations, financial condition and liquidity, as well as our critical accounting policies and estimates that require significant judgment and thus have the most significant potential impact on our Consolidated Financial Statements. This section provides an analysis of our financial results for the year ended December 31, 2025 compared to the same period in the prior year.

Company Overview

Summit Therapeutics Inc. (“we”, “Summit” or the “Company”) is a biopharmaceutical company focused on the discovery, development, and commercialization of patient-, physician-, caregiver- and societal-friendly medicinal therapies intended to improve quality of life, increase potential duration of life, and resolve serious unmet medical needs. The Company’s pipeline of product candidates is designed with the goal to become the patient-friendly, new-era standard-of-care medicines, in the therapeutic area of oncology.

The Company’s current lead development candidate is ivonescimab, a novel, potential first-in-class bispecific antibody intending to combine the effects of immunotherapy via a blockade of PD-1 with the anti-angiogenesis effects of an anti-VEGF compound into a single molecule. On December 5, 2022, the Company entered into the License Agreement with Akeso pursuant to which the Company has in-licensed intellectual property rights related to ivonescimab (as amended, the “License Agreement”). Through the License Agreement, the Company obtained the rights to develop and commercialize ivonescimab in the United States, Canada, Europe, and Japan. The License Agreement and transaction closed in January 2023 following customary waiting periods. On June 3, 2024, the Company entered into the Second Amendment with Akeso to expand its territories covered under the License Agreement to also include Latin America, including Mexico and all countries in Central America and South America, the Middle East and Africa. The Company’s operations are focused on the development of ivonescimab and other future activities, as the Company determines.

The Company is developing ivonescimab in NSCLC and CRC, specifically conducting Phase III clinical trials in the following proposed indications:

(a) ivonescimab combined with chemotherapy in patients with EGFR-mutated, locally advanced or metastatic non-squamous NSCLC who were previously treated with a third-generation EGFR TKI (“HARMONi”);

(b) ivonescimab combined with chemotherapy in patients with first-line metastatic NSCLC (including separate statistical analyses planned for patients with squamous NSCLC and non-squamous NSCLC) (“HARMONi-3”);

70

(c) ivonescimab monotherapy in patients with first-line metastatic NSCLC whose tumors have high PD-L1 expression (“HARMONi-7”); and

(d) ivonescimab combined with chemotherapy in patients with first-line unresectable metastatic CRC (“HARMONi-GI3”).

In October 2024, the Company completed enrollment in its HARMONi clinical trial. In May 2025, we announced topline results from our multiregional, double-blinded, placebo-controlled, Phase III study HARMONi. At the prespecified primary data analysis, ivonescimab in combination with chemotherapy demonstrated a statistically significant improvement in PFS, the magnitude of which we believe to be clinically meaningful, with a hazard ratio of 0.52 (95% CI: 0.41 – 0.66; p0.00001) compared to placebo in combination with chemotherapy; median PFS was 6.8 months for those patients receiving ivonescimab plus chemotherapy compared to 4.4 months for those receiving chemotherapy. PFS was assessed by BICR.

We believe the PFS hazard ratio that was observed in both Asian and Western sub-populations to be clinically meaningful. The primary analysis demonstrated the consistency of the magnitude of the PFS benefit between patients randomized in Asian and Western territories, as well as the consistency in a single-region study (HARMONi-A) with this multiregional study.

In a longer-term follow-up of PFS, which included all Western patients and at least six months of follow-up time for all patients, ivonescimab plus chemotherapy demonstrated a consistent hazard ratio in PFS as the primary PFS analysis observed HR = 0.57; 95% CI: 0.46 – 0.71). With the longer-term follow-up analysis, consistency of the magnitude of PFS benefit was demonstrated between patients randomized in Asia and Western patients when measured by hazard ratio. This longer-term follow-up analysis of PFS was performed at the time of the primary OS analysis.

Ivonescimab in combination with chemotherapy showed a positive trend in OS in the primary analysis without achieving a statistically significant benefit with a hazard ratio of 0.79 (95% CI: 0.62 – 1.01; p=0.057). This trend provides further support for its use in EGFRm NSCLC post-TKI therapy, a setting where high unmet need continues to exist with limited approved options in the United States and other western territories. Currently there are no FDA-approved regimens that have demonstrated a statistically significant OS benefit in this patient setting. Both Asian and North American patients demonstrated a positive trend in OS. The results of the primary analysis in this multiregional study were consistent with that of the single-region randomized Phase III HARMONi-A study, which demonstrated a statistically significant OS benefit with a hazard ratio of 0.74 in the primary OS analysis in a similar patient population.

In September 2025, an additional ad hoc OS analysis was performed for the HARMONi study, whereby the Western patients were followed for a longer period of time (Asian patients were locked at the time of the primary analysis). In this analysis that included longer-term follow-up of Western patients (median follow-up time of Western patients of 13.7 months), a hazard ratio consistent with the primary analysis was observed with an improved nominal p-value (HR=0.78; 95% CI: 0.62 – 0.98; nominal p=0.0332). Median OS for this analysis remained the same in both arms as was observed in the primary analysis. Median OS in Western patients receiving ivonescimab was 17.0 months compared to 14.0 months for those receiving placebo (HR=0.84); median OS in North American patients, specifically, had not yet been reached in the ivonescimab arm compared to 14.0 months in the placebo arm (HR=0.70). The hazard ratios for Western patients in totality, as well as patients from the North American and European regions individually, improved from the primary OS analysis to the analysis with longer-term follow-up of Western patients. Consistent benefit was observed across pre-defined subgroups.

The dual primary endpoints were allocated separate alpha levels and tested individually. The alpha was recycled from the PFS to the OS analysis upon the successful achievement of the PFS endpoint.

Based on the results of the HARMONi clinical trial, we submitted a BLA in the fourth quarter of 2025 in order to seek approval for ivonescimab plus chemotherapy for this proposed indication. The positive results of the multiregional Phase III study are detailed further under “Product Pipeline” below. As previously disclosed, the FDA noted that a statistically significant OS benefit is necessary to support marketing authorization in this setting. After careful consideration of the safety and efficacy profile of the current FDA-approved options for patients in this setting, the positive results of the Phase III multiregional study, including regional consistency, as well as discussions with key opinion leaders and those physicians who have administered ivonescimab to patients in a clinical study setting, we believe that the safety and efficacy data generated in the HARMONi study demonstrates that the ivonescimab regimen offers a potential treatment option for patients impacted by EGFR-mutant NSCLC in this setting with a favorable benefit-risk profile despite the lack of a statistically significant OS benefit. Summit announced in January 2026 that the FDA accepted for filing the BLA seeking approval for ivonescimab in combination with chemotherapy for this proposed indication. The FDA noted it intends to perform a complete review of the accepted and filed BLA, including planned mid-cycle and wrap-up meetings, and, subject to major deficiencies not being identified during the FDA’s review, proposed labeling, prior to the Prescription Drug User Fee Act goal action date of November 14, 2026.

71

Key Components of our Results of Operations

Research and Development Expenses

Research and development expenses consist of all costs associated with our research and development activities.

These include:

•costs incurred in conducting our preclinical studies and clinical trials through contract research and development organizations, including, but not limited to, preclinical toxicology, pharmacology, formulation and manufacturing work, as well as regulatory, operational, drug supply and treatment costs related to conducting the study;

•laboratory and vendor expenses incurred in relation to our preclinical, non-clinical and clinical studies;

•costs incurred in supply chain development and scale up activities to support product registration;

•employee related expenses, which include salary, benefits and stock-based compensation, for our research and development staff;

•costs incurred in development and conduct of training and education related our development candidates; and

•facilities, depreciation and other expenses, which include direct and allocated expenses for rent and maintenance of facilities, insurance and other supplies.

We utilize our employee and infrastructure resources across multiple research projects. We track expenses related to our clinical programs and certain preclinical programs on a per project basis. We expect our research and development expenses to continue to be significant as we initiate our planned clinical trials of ivonescimab, and continue our activities to initiate preclinical programs for future product candidates. The timing and amount of these expenses will depend upon the outcome of our clinical trials and the associated costs. The timing and amount of these expenses will also depend on the costs associated with potential future clinical trials of our product candidates and the related expansion of our research and development organization, regulatory requirements, advancement of our preclinical programs and product candidate manufacturing costs.

General and Administrative Expenses

General and administrative expenses consist primarily of salaries and benefits related to our executive, finance, business development, human r

[Excerpt truncated for page length; the complete text is on the linked full-MD&A page.]