# EDGAR Filing Document

**Accession Number:** 0001599298
**File Stem:** 0001599298-26-000004
**Filing Date:** 2026-1
**Character Count:** 59952
**Document Hash:** a0357d88fca5ea6623fdd1dbbb279131
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001599298-26-000004.hdr.sgml**: 20260112

**ACCESSION NUMBER**: 0001599298-26-000004

**CONFORMED SUBMISSION TYPE**: 8-K

**PUBLIC DOCUMENT COUNT**: 39

**CONFORMED PERIOD OF REPORT**: 20260112

**ITEM INFORMATION**: Results of Operations and Financial Condition

**ITEM INFORMATION**: Regulation FD Disclosure

**ITEM INFORMATION**: Financial Statements and Exhibits

**FILED AS OF DATE**: 20260112

**DATE AS OF CHANGE**: 20260112

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Summit Therapeutics Inc.
- **CENTRAL INDEX KEY:** 0001599298
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 371979717
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 8-K
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-36866
- **FILM NUMBER:** 26524688

**BUSINESS ADDRESS:**
- **STREET 1:** 601 BRICKELL KEY DRIVE
- **STREET 2:** SUITE 1000
- **CITY:** MIAMI
- **STATE:** FL
- **ZIP:** 33131
- **BUSINESS PHONE:** 305-203-2034

**MAIL ADDRESS:**
- **STREET 1:** 601 BRICKELL KEY DRIVE
- **STREET 2:** SUITE 1000
- **CITY:** MIAMI
- **STATE:** FL
- **ZIP:** 33131

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** Summit Therapeutics plc
- **DATE OF NAME CHANGE:** 20150219

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** Summit Corp plc
- **DATE OF NAME CHANGE:** 20140205

?xml version='1.0' encoding='ASCII'? smmt-20260112

**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): <u>January 12, 2026</u>

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| | | |
|:---|:---|:---|
| Summit Therapeutics Inc. | Summit Therapeutics Inc. | Summit Therapeutics Inc. |
| (Exact Name of Registrant as Specified in Its Charter) | (Exact Name of Registrant as Specified in Its Charter) | (Exact Name of Registrant as Specified in Its Charter) |
| Delaware | 001-36866 | 37-1979717 |
| (State or Other Jurisdiction<br>of Incorporation) | (Commission<br>File Number) | (IRS Employer<br>Identification No.) |
| 601 Brickell Key Drive, Suite 1000, Miami, FL | 601 Brickell Key Drive, Suite 1000, Miami, FL | 33131 |
| (Address of Principal Executive Offices) | (Address of Principal Executive Offices) | (Zip Code) |

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Registrant's Telephone Number, Including Area Code: <u>(305) 203-2034</u>

Not applicable <br> (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:

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| | | |
|:---|:---|:---|
| 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 |

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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. ☐

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| | |
|:---|:---|
| **Item 2.02** | **Results of Operations and Financial Conditions.** |

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As of December 31, 2025, the preliminary unaudited balance of cash, cash equivalents, and short-term investments of Summit Therapeutics Inc. (the "Company") was approximately $710 million. This amount is preliminary and is subject to completion of financial closing procedures. As a result, this amount may differ materially from the amount that will be reflected in the Company's consolidated financial statements for the year ended December 31, 2025.

In accordance with General Instruction B.2 of Form 8-K, the information set forth under Item 2.02 and in Exhibits 99.1 and 99.2 shall not be deemed "filed" for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such filing.

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| | |
|:---|:---|
| **Item 7.01** | **Regulation FD Disclosure.** |

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On January 12, 2026, the Company intends to present at the 44th Annual J.P. Morgan Healthcare Conference. A copy of the presentation is furnished as Exhibit 99.1 to this Current Report on Form 8-K and is incorporated by reference into this Item 7.01 as if fully set forth herein.

On January 12, 2026, the Company issued a press release announcing the submission of a Biologics License Application to U.S. Food and Drug Administration seeking approval for ivonescimab in combination with chemotherapy in second line or later treatment of patients with epidermal growth factor receptor-mutated locally advanced or metastatic non-squamous non-small cell lung cancer. A copy of the press release is attached as Exhibit 99.2 to this Current Report on Form 8-K and is incorporated by reference herein.

On January 12, 2026, the Company issued a press release announcing a clinical trial collaboration with GSK plc ("GSK") to evaluate ivonescimab in combination with GSK's risvutatug rezetecan (also known as GSK'227), GSK's novel investigational B7-H3 targeting antibody drug conjugate (ADC), across multiple solid tumor settings, including small cell lung cancer (SCLC). A copy of the press release is attached as Exhibit 99.3 to this Current Report on Form 8-K and is incorporated by reference herein.

In accordance with General Instruction B.2 of Form 8-K, the information set forth under Item 7.01 and in Exhibits 99.1, 99.2 and 99.3 shall not be deemed "filed" for purposes of Section 18 of the Exchange Act, as amended, or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such filing.

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| | |
|:---|:---|
| **Item 9.01** | **Financial Statements and Exhibits.** |

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(d) Exhibits

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| | |
|:---|:---|
| **<u>Exhibit Number</u>** | **<u>Description</u>** |
| 99.1 | <u>[Investor Presentation Slides made available on January 12, 2026](jpm2026investordeck_fina.htm)</u> |
| 99.2 | <u>[Press release, dated January 12, 2026](a2026_prx0112xblasubmiss.htm)</u> |
| 99.3 | <u>[Press release, dated January 12, 2026](a2026_prx0112xannounceme.htm)</u> |
| 104 | Cover Page Interactive Data File (embedded within the Inline XBRL document) |

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**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.

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| | | |
|:---|:---|:---|
| | **SUMMIT THERAPEUTICS INC.** | **SUMMIT THERAPEUTICS INC.** |
| Date: January 12, 2026 | By: | /s/ Manmeet S. Soni |
|  |  | Chief Operating Officer, Chief Financial Officer and Director |
|  |  | (Principal Financial Officer) |

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## Exhibit 99.1

![](jpm2026investordeck_fina001.jpg)

44th Annual J.P. Morgan Healthcare Conference January 12, 2026 BOB DUGGAN Chairman & Co-Chief Executive Officer DR. MAKY ZANGANEH President & Co-Chief Executive Officer

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![](jpm2026investordeck_fina002.jpg)

Forward Looking Statement Any statements in this presentation about the Company's future expectations, plans and prospects, including but not limited to, statements about the clinical and preclinical development of the Company's product candidates, entry into and actions related to the Company's partnership with Akeso Inc., the Company's anticipated spending and cash runway, the therapeutic potential of the Company's product candidates, the potential commercialization of the Company's product candidates, the timing of initiation, completion and availability of data from clinical trials, the potential submission of applications for marketing approvals, the expected timing of BLA submissions or FDA decisions, potential acquisitions, statements about the previously disclosed At-The-Market equity offering program ("ATM Program"), the expected proceeds and uses thereof, the Company's estimates regarding stock-based compensation, and other statements containing the words "anticipate," "believe," "continue," "could," "estimate," "expect," "intend," "may," "plan," "potential," "predict," "project," "should," "target," "would," and similar expressions, constitute forward-looking statements within the meaning of The Private Securities Litigation Reform Act of 1995. Actual results may differ materially from those indicated by such forward-looking statements as a result of various important factors, including the Company's ability to sell shares of our common stock under the ATM Program, the conditions affecting the capital markets, general economic, industry, or political conditions, including the effects of geopolitical developments, domestic and foreign trade policies, and monetary policies, the results of our evaluation of the underlying data in connection with the development and commercialization activities for ivonescimab, the outcome of discussions with regulatory authorities, including the Food and Drug Administration, the uncertainties inherent in the initiation of future clinical trials, availability and timing of data from ongoing and future clinical trials, the results of such trials, and their success, global public health crises, that may affect timing and status of our clinical trials and operations, whether preliminary results from a clinical trial will be predictive of the final results of that trial or whether results of early clinical trials or preclinical studies will be indicative of the results of later clinical trials, whether business development opportunities to expand the Company's pipeline of drug candidates, including without limitation, through potential acquisitions of, and/or collaborations with, other entities occur, expectations for regulatory approvals, laws and regulations affecting government contracts and funding awards, availability of funding sufficient for the Company's foreseeable and unforeseeable operating expenses and capital expenditure requirements and other factors discussed in the "Risk Factors" and "Management's Discussion and Analysis of Financial Condition and Results of Operations" sections of filings that the Company makes with the Securities and Exchange Commission. Summit defines a "positive study" as a clinical study that with one or more prespecified primary endpoints in which one of those endpoints achieves a statistically significant benefit according to the protocol or statistical analysis plan. Any change to our ongoing trials could cause delays, affect our future expenses, and add uncertainty to our commercialization efforts, as well as to affect the likelihood of the successful completion of clinical development of ivonescimab. Accordingly, readers should not place undue reliance on forward- looking statements or information. In addition, any forward-looking statements included in this presentation represent the Company's views only as of the date of this release and should not be relied upon as representing the Company's views as of any subsequent date. The Company specifically disclaims any obligation to update any forward-looking statements included in this presentation. Ivonescimab is an investigational therapy not presently approved by any regulatory authority other than China's National Medical Products Administration (NMPA). Summit Therapeutics and the Summit Therapeutics logo are trademarks of Summit Therapeutics Inc. Copyright 2026, Summit Therapeutics Inc. All Rights Reserved.2 Summit Proprietary Information - Do Not Copy or Distribute JPM 2026 Presentation \| 1/2026

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![](jpm2026investordeck_fina003.jpg)

Ivonescimab is an investigational therapy not presently approved by any regulatory authority other than China's National Medical Products Administration (NMPA). 3 Anti-VEGF Anti-PD-1 US Biologics License Application (BLA) Submitted to the FDA in the Fourth Quarter 2025 Ivonescimab + Chemo vs. Chemo in 2L+ EGFRm NSCLC SUBMITTED! Abbreviations: 2L+=second-line or later line; Chemo=Chemotherapy; EGFRm=epidermal growth factor receptor mutation-positive; FDA=US Food and Drug Administration; NSCLC=non-small cell lung cancer; PD-1=programmed cell death protein 1; VEGF=vascular endothelial growth factor; vs.=versus Summit Proprietary Information - Do Not Copy or Distribute JPM 2026 Presentation \| 1/2026

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![](jpm2026investordeck_fina004.jpg)

Ivonescimab is an investigational therapy not presently approved by any regulatory authority other than China's National Medical Products Administration (NMPA). Summit Proprietary Information - Do Not Copy or Distribute JPM 2026 Presentation \| 1/20264 Ivonescimab Anti-VEGF Anti-PD-1 Includes both Summit and Akeso trials Total Ivonescimab Trials Sponsored by Summit or Akeso2 Patients Dosed in All Clinical Trials2 Patients Dosed Commercially in China Phase III Trials in Multiple Tumor Types1 Positive Phase III Readouts to Date The only in-class Phase III Readouts Leadership in global oncology with a proven track record with high-speed and quality execution. Proven Track Record 4 Global Phase III Trials Mission: Patients First To improve quality of life, increase potential duration of life, by resolving serious unmet medical needs Indications Approved in China by the NMPA 4 Phase III Trials with Positive Results PD-1 x VEGF Class Frontrunner with Multi-Year Lead 14 Phase III Trials1 >4K Trial Patients 2 Chinese Approvals >60K Commercial Patients in China 42 Sponsored Trials Abbreviations: PD-1=programmed cell death protein 1; VEGF=vascular endothelial growth factor; NMPA = National Medical Products Administration (China) References: 1. Total sponsored (by Summit or Akeso) clinical trials as of January 6, 2026, via clinicaltrials.gov or public announcement; 2. Data on File 56, 57. Summit Therapeutics Inc. Total Trials Involving Ivonescimab on clinicaltrials.gov2 116 Total Trials

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Ivonescimab is an investigational therapy not presently approved by any regulatory authority other than China's National Medical Products Administration (NMPA). Summit Proprietary Information - Do Not Copy or Distribute JPM 2026 Presentation \| MAT-SMTxxx-xxxx \| 1/20265 Cooperative Binding Potentially Drives Synergistic Anti-Tumor Activity Ivonescimab is an investigational therapy not presently approved by any regulatory authority other than China's National Medical Products Administration (NMPA). Anti-VEGF Anti-PD-1 Intentional, Potentially Favorable Molecular Profile Structure may lead to optimized binding in TME1 Targeting PD-1 may lead to better efficacy profile1 7 to 10-day half-life could potentially lead to a favorable safety profile.2-4 Dual Blockade of PD-1 & VEGF1 Increased Avidity in TME Presence of VEGF-A efficiently enhances the binding affinity to PD-1 by several fold1 (in vitro) Enhanced Activity of T Cells VEGF dimer leads to potential interconnection of ivonescimab molecules which may increase activity of T cells1 (in vitro) Abbreviations: PD-1=programmed cell death protein 1; TME=tumor microenvironment; VEGF=vascular endothelial growth factor 1. Zhong T, et al. iScience. 2024;28(3):111722.; 2. Zhao Y. et al., eClinicalMedicine. 2023; 3(62): 102106; 3. Wang L, et al. J Thorac Oncol. 2024;19(3):465-475; 4. Data on File 39. Summit Therapeutics Inc. 1/2026

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Ivonescimab is an investigational therapy not presently approved by any regulatory authority other than China's National Medical Products Administration (NMPA). Summit Proprietary Information - Do Not Copy or Distribute JPM 2026 Presentation \| 1/20266 Abbreviations: 1L=first-line; 2L=second-line; AG=albumin-bound paclitaxel plus gemcitabine; BTC=biliary tract cancer; Chemo=chemotherapy; CPS=combined positive score; CRC=colorectal cancer; EGFRm+=epidermal growth factor receptor mutant positive; GEJ=gastroesophageal junction; HCC=hepatocellular carcinoma; HNSCC=head and neck squamous cell carcinoma; mAb=monoclonal antibody; NSCLC=non-small-cell lung cancer; OC=ovarian cancer; PD-L1=programmed cell death-ligand 1; PDAC=pancreatic ductal adenocarcinoma; SCLC=Small Cell Lung Cancer; TIGIT=T cell immunoreceptor with Ig and ITIM domains; TNBC=triple negative breast cancer; vs.=versus. Reference: ClinicalTrials.gov These ivonescimab clinical trials are being conducted in China and/or Australia and are fully sponsored and managed by Akeso. TUMOR TYPE STUDY LINE & INDICATION REGIMEN STATUS Approved PHASE 1/1b 2 3 Lung 2L advanced EGFRm+ NSCLC ivonescimab + chemo vs. placebo + chemo Active, Recruiting Complete 1L metastatic NSCLC (all PD-L1 levels) ivonescimab vs. pembrolizumab Active, Recruiting Complete 1L advanced or metastatic NSCLC ivonescimab + chemo vs. tislelizumab + chemo Active, Recruiting Complete 2L advanced or metastatic NSCLC progressed on or after PD-L1 therapy ivonescimab + docetaxel vs. placebo + docetaxel Not Yet Recruiting Consolidation treatment SCLC not progressed after chemoradiation ivonescimab vs. placebo Recruiting AK112-205 Resectable NSCLC ivonescimab vs. ivonescimab + chemo Active, Recruiting Complete AK112-208 1L advanced or metastatic NSCLC ivonescimab + cadonilimab ± chemo Recruiting Breast 1L inoperable locally advanced/ metastatic TNBC ivonescimab + nab-paclitaxel vs. placebo + nab-paclitaxel Recruiting AK117-203 1L metastatic TNBC ivonescimab + chemo Recruiting Gynecologic AK104-221 2L OC ivonescimab ± chemo ± cadonilimab Recruiting AK112-211 1L platinum-sensitive OC ivonescimab ± chemo ± olaparib Recruiting Head and Neck 1L recurrent or metastatic HNSCC with PD-L1 positive (CPS ≥1) ivonescimab + AK117 vs. placebo + pembrolizumab Recruiting Gastrointestinal 1L unresectable locally advanced or metastatic BTC ivonescimab + chemo vs. durvalumab + chemo Active, Recruiting Complete 1L metastatic PDAC ivonescimab + chemo ± AK117 vs. placebo + chemo Recruiting 1L metastatic CRC ivonescimab + chemo vs. bevacizumab + chemo Recruiting AK112-209 1L advanced HCC ivonescimab ± anti-TIGIT antibody ± cadonilimab ± anti-TIGIT/TGF-β vs. sintilimab + bevacizumab Recruiting AK112-210 1L metastatic PDAC ivonescimab ± cadonilimab ± AG vs. AG Recruiting AK119-202 1L or 2L microsatellite stable CRC ivonescimab + anti-CD73 mAb ± chemo Recruiting AK130-201 2L advanced BTC ivonescimab ± anti-TIGIT/TGF-β or ivonescimab Not yet recruiting Various Cancers AK117-202 1L or 2L advanced or metastatic NSCLC, GEJ, BTC, PDAC ivonescimab + ligufalimab ± chemo Active, Not Recruiting AK127-104 1L advanced malignant tumors ivonescimab + anti-TIGIT antibody Not yet recruiting Lung 2L advanced EGFRm+ NSCLC ivonescimab + chemo vs. placebo + chemo Active, Recruiting Complete 1L metastatic NSCLC ivonescimab + chemo vs. pembrolizumab + chemo Recruiting 1L metastatic PD-L1 high (≥50%) NSCLC ivonescimab vs. pembrolizumab Recruiting Gastrointestinal 1L metastatic CRC ivonescimab + chemo vs. bevacizumab + chemo Recruiting Ivonescimab Development: Summit + Akeso Pipelines Phase I and II trials completed by Akeso.

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Ivonescimab is an investigational therapy not presently approved by any regulatory authority other than China's National Medical Products Administration (NMPA). Summit Proprietary Information - Do Not Copy or Distribute JPM 2026 Presentation \| 1/20267 Ivonescimab Development Plan Ivo esci ab evelop e t: Summit Pipeline Summit initiating additional set of Phase III studies Further details coming starting in Q1 2026 References: 1. In Summit license territories, Data on File 55. Summit Therapeutics Inc. Supported = at a minimum, a notification of support communicated to PI; 2. Publications available at smmttx.com, Accessed on Jan 6, 2026. Abbreviations: 1L=first-line; 2L=second-line; ADC=antibody drug conjugate; Chemo=chemotherapy; CRC=colorectal cancer; EGFRm+=epidermal growth factor receptor mutant positive; ISTs=Investigator Sponsored Trials; NSCLC=non-small-cell lung cancer; PDAC=pancreatic ductal adenocarcinoma; PD-L1=programmed cell death-ligand 1; RAS=renin-angiotensin system; RASi=RAS inhibitor; RAS(ON)i=RAS inhibitor to RAS proteins in ON state (revmed.com/science, Accessed Jan 10, 2026); SCLC=small cell lung cancer; incl.=including; vs.=versus. Reference: ClinicalTrials.gov Present-time biopharma confidence in ivonescimab is a significant governor in our go-forward clinical development expense Collaborations RevMed: Novel RAS(ON)i: NSCLC, PDAC, CRC GSK: Novel B7-H3: multi-tumor incl. SCLC More Planned in 2026 >60 ISTs1 15 Currently Enrolling 5 via MD Anderson Collaboration 46 Ivonescimab Posters, Publications & Presentations2 RASi ADC llaborations >60 ISTs Supported1 >46 Phase I and II trials completed by Akeso.

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Anti-VEGF Anti-PD-1 Ivonescimab 1L NSCLC Ivonescimab vs. Anti-PD-1 +/- chemo Presented at WCLC 2024 Presidential Symposium1 The Lancet2 Approved indication in China Awaiting data maturation for OS Squamous, PD-L1 All-Comers Ivonescimab + chemo vs. tislelizumab (PD-1) + chemo Presented at ESMO 2025 Presidential Symposium3 The Lancet4 sNDA pending in China Awaiting data maturation for OS 2L+ EGFRm NSCLC Ivonescimab + Chemo vs. Placebo + Chemo EGFRm after a TKI Ivonescimab + chemo vs. placebo + chemo Presented at ASCO 20245 OS Update: SITC Nov. 20257 JAMA6 Approved indication in China EGFRm after a 3rd-gen TKI Ivonescimab + chemo vs. placebo + chemo Presented at WCLC 2025 Presidential Symposium8 US BLA submitted Q4 2025 Ivonescimab is an investigational therapy not presently approved by any regulatory authority other than China's National Medical Products Administration (NMPA). 8 PD-L1 Positive, Monotherapy Ivonescimab vs. pembrolizumab References: 1. Wang C, et al. HARMONi-2. Presented at WCLC 2024.; 2. Xiong A, et al. Lancet. 2025;405(10481):839-849; 3. Lu S, et al. HARMONi-6. Presented at ESMO 2025.; 4. Chen Z, et al. Lancet. 2025;406(10515):2078-2088.; 5. Zhang L, et al. HARMONi-A study. Presented at ASCO 2024.; 6. Fang W, et al. JAMA. 2024;332(7):561-570.; 7. Zhang L, et al. Final OS Analysis: HARMONi-A. Presented at SITC 2025.; 8. Goldman J, et al. HARMONi. Presented at WCLC 2025. Abbreviations: 1L=first-line; 2L=second-line; ASCO=American Society of Clinical Oncology; chemo=chemotherapy; EGFRm=epidermal growth factor receptor mutation; ESMO=European Society for Medical Oncology; gen=generation; JAMA=The Journal of the American Medical Association; NSCLC=non-small cell lung cancer; OS=overall survival; PD-1=programmed cell death protein 1; PD-L1=programmed cell death-ligand 1; SITC=The Society for Immunotherapy of Cancer; sNDA=Supplemental New Drug Application (for marketing authorization); TKI=tyrosine kinase inhibitor; VEGF=vascular endothelial growth factor; vs.=versus; WCLC=World Conference on Lung Cancer. Four Phase III Clinical Studies with Positive Results Summit Proprietary Information - Do Not Copy or Distribute JPM 2026 Presentation \| 1/2026

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9 Summit Proprietary Information - Do Not Copy or Distribute JPM 2026 Presentation \| 1/2026 Xiong A et al Lancet 2025; 402:839-49 Chen Z et al Lancet 2025; 406:2078-2088Goldman et al WCLC 2025 (2L+, EGFR+) (1L, squamous)(1L, PD-L1+) Abbreviations: 1L=first-line; 2L=second-line; chemo=chemotherapy; CI=confidence interval; EGFR+=epidermal growth factor receptor positive; HR=hazard ratio; NSCLC=non-small cell lung cancer; PD-1=programmed cell death protein 1; PD-L1=programmed cell death-ligand 1; PFS=progression-free survival; TRAE=treatment- related adverse event; WCLC=World Conference on Lung Cancer. Reference: clinicaltrials.gov Three Settings: Four Phase III Studies with Positive Results Ivonescimab demonstrated statistically significant and clinically meaningful PFS benefit in patients with NSCLC in Ph III studies Regulatory approvals in China based on HARMONi-A and HARMONi-2; HARMONi-6 currently under regulatory review in China V HARMONi-6 Ivonescimab + chemo (N=266) PD-1 (tislelizumab) + chemo (N=265) TRAEs 264 (99.2%) 261 (98.5%) Serious TRAEs 86 (32.3%) 80 (30.2%) TRAEs Leading to Discontinuation 9 (3.4%) 11 (4.2%) TRAEs Leading to Death 8 (3.0%) 10 (3.8%) HARMONi Ivonescimab + chemo (N=218) Placebo + chemo (N=218) TRAEs 207 (95.0%) 203 (93.1%) Serious TRAEs 61 (28.0%) 33 (15.1%) TRAEs Leading to Discontinuation 16 (7.3%) 11 (5.0%) TRAEs Leading to Death 4 (1.8%) 5 (2.3%) HARMONi-2 Ivonescimab (N=197) PD-1 (pembrolizumab) (N=199) TRAEs 177 (89.8%) 163 (81.9%) Serious TRAEs 41 (20.8%) 32 (16.1%) TRAEs Leading to Discontinuation 3 (1.5%) 6 (3.0%) TRAEs Leading to Death 1 (0.5%) 2 (1.0%) HR=0.52 (95% CI: 0.41-0.66, p<0.0001) HR=0.60 (95% CI: 0.46-0.78, p<0.0001) HR=0.51 (95% CI: 0.38-0.69, p<0.0001) Ivonescimab is an investigational therapy not presently approved by any regulatory authority other than China's National Medical Products Administration (NMPA).

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Ivonescimab is an investigational therapy not presently approved by any regulatory authority other than China's National Medical Products Administration (NMPA). 10 Abbreviations: 1L=first-line; 2L=second-line; CRC=colorectal cancer; EGFRm+=epidermal growth factor receptor mutant; ESMO=European Society for Medical Oncology; FDA=US Food and Drug Administration; FPI=first patient in; iOS= interim overall survival; NSCLC=non-small-cell lung cancer; OS=overall survival; PD-1=programmed cell death protein 1; PD-L1=programmed cell death-ligand 1; PD-L1+=PD-L1 positive; PFS=progression-free survival; Ph3=Phase 3; SITC=Society for Immunotherapy of Cancer; SQ=squamous; US=United STatesWCLC=World Conference on Lung Cancer. 2024 2025 Data, iOS: Ph3 1L NSCLC PD-L1+ (China)6,7 NMPA Approval: 1L NSCLC PD-1+ (China) FPI: Ph3 1L CRC (Global) Data, PFS: Ph3 1L NSCLC SQ (China) @ ESMO8,9 Data, PFS & OS: Ph3 2L+ EGFRm NSCLC (Global) @ WCLC10 FDA Submission: 2L+ EGFRm NSCLC (US) Data, OS: Ph3 2L+ EGFRm NSCLC (China) @ SITC11 Trial Amendment: Ph3 1L NSCLC: Initiation of Non-Squamous Portion in Addition to Enrolling Patients with Squamous NSCLC (Global)3 Data, PFS, iOS: Ph3 2L+ EGFRm NSCLC (China) 4,5 NMPA Approval: 2L+ EGFRm NSCLC (China) References: 1. Wang C, et al. HARMONi-2. Presented at WCLC 2024.; 2. Passaro A, et al. HARMONi-7 TiP. Presented at ELCC 2025.; 3. Zhang J, et al. HARMONi-3 TiP; 4. Zhang L, et al. HARMONi-A study. Presented at ASCO 2024.; 5. Fang W, et al. JAMA. 2024;332(7):561-570.; 6. Xiong A, et al. Lancet. 2025;405(10481):839-849; 7. Summit Press Release. April 25, 2025.; 8. Lu S, et al. HARMONi-6. Presented at ESMO 2025.; 9. Chen Z, et al. Lancet. 2025;406(10515):2078-2088.; 10. Goldman J, et al. HARMONi. Presented at WCLC 2025.; 11. Zhang L, et al. Final OS Analysis: HARMONi-A. Presented at SITC 2025. FPI: Ph3 1L NSCLC PD-L1 High (Global)2 Data, PFS: Ph3 1L NSCLC PD-L1+ (China)1 Ivonescimab Milestones Achieved Summit Proprietary Information - Do Not Copy or Distribute JPM 2026 Presentation \| 1/2026

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China Ivonescimab Clinical Questions Answered in 2025 Ivonescimab + Chemo vs. Tislelizumab + Chemo in 1L NSCLC 4,5 Ivo monotherapy: clinically meaningful early OS trend vs. pembro monotherapy (OS HR = 0.777 at 39% maturity based on health authority- requested interim analysis)2 Ivonescimab is an investigational therapy not presently approved by any regulatory authority other than China's National Medical Products Administration (NMPA). Global Potential for positive results from China studies to translate to the west? Ivonescimab + Chemo vs. Chemo in 2L+ EGFRm NSCLC 1 Potential for positive PFS data to translate to positive OS data? Potential for positive monotherapy results to be sustained with addition of chemotherapy? Ivonescimab + Chemo vs. Chemo in 2L+ EGFRm NSCLC 2 References: 1. Goldman J, et al. HARMONi. Presented at WCLC 2025.; 2. Zhang L, et al. Final OS Analysis: HARMONi-A. Presented at SITC 2025.; 3. Summit Press Release. April 25, 2025.; 4. Lu S, et al. HARMONi-6. Presented at ESMO 2025.; 5. Chen Z, et al. Lancet. 2025;406(10515):2078-2088. Abbreviations: 1L=first-line; 2L=second-line; Chemo=chemotherapy; EGFRm+=epidermal growth factor receptor mutant positive; NSCLC=non-small- cell lung cancer; HR=hazard ratio; OS=overall survival; PFS=progression-free survival; vs.=versus. Reference: ClinicalTrials.gov Strong OS Trends, HR <0.80 1,3 Summit Proprietary Information - Do Not Copy or Distribute JPM 2026 Presentation \| 1/202611

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Ivonescimab is an investigational therapy not presently approved by any regulatory authority other than China's National Medical Products Administration (NMPA). Summit Proprietary Information - Do Not Copy or Distribute JPM 2026 Presentation \| 1/202612 Shaping the Path to Become a Commercial Entity 1Q26 Further details beginning this quarter on new global Phase IIIs 1H26 HARMONi-3 SQ: Completion of enrollment expected 2H26 HARMONi-3 SQ: PFS, interim OS data readout expected HARMONi-3 nSQ: Completion of enrollment expected HARMONi: BLA Decision in 2L+ EGFRm NSCLC expected 1H27 HARMONi-3 nSQ: PFS data readout expected Anti-VEGF Anti-PD-1 Abbreviations: 2L=second-line; BLA=Biologics License Application; EGFRm+=epidermal growth factor receptor mutant positive; NSCLC=non-small-cell lung cancer; nSQ=non-squamous; OS=overall survival; PD-1=programmed cell death protein 1; PD-L1=programmed cell death-ligand 1; PFS=progression-free survival; SQ=squamous; VEGF=vascular endothelial growth factor.

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Ivonescimab is an investigational therapy not presently approved by any regulatory authority other than China's National Medical Products Administration (NMPA). Summit Proprietary Information - Do Not Copy or Distribute JPM 2026 Presentation \| 1/2026 Strong Balance Sheet to Kick Off 2026 13 ~$710M Unaudited Cash as of 12/31/2025 $0 No Debt as of 12/31/2025

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Ivonescimab is an investigational therapy not presently approved by any regulatory authority other than China's National Medical Products Administration (NMPA). Summit Proprietary Information - Do Not Copy or Distribute JPM 2026 Presentation \| 1/2026 Potential growth beyond current PD-(L)1 & VEGF indications Examples of opportunities include: PD-L1 low TNBC, EGFRm NSCLC Platform Opportunity 14 for PD-(L)1 Inhibitors + VEGF Inhibitors >50 approved indications1 + Checkpoint Inhibitor Global Market >$90B in 20282 >$20B NSCLC PD-(L)1: >$50B in 20243 $30B pembrolizumab in 20244 >$20B in 20285 >$110B VEGF Inhibitor Global Market 1. KEYTRUDA® USPI, OPDIVO® USPI, LIBTAYO® USPI, IMFINZI® USPI, BAVENCIO® USPI, JEMPERLI® USPI, TECENTRIQ® USPI, ZYNYZ® USPI, AVASTIN® USPI, CYRAMZA® USPI, LENVIMA® USPI, INLYTA® USPI, SUTENT® USPI. 2. TD Cowen and IQVIA, estimates. 3. Stifel report, estimate; compilation of Form 10-K and 20-F as filed with the US SEC. 4. MRK 2024 Form 10-K, as filed with the US SEC. 5. TD Cowen and IQVIA, estimate. Abbreviations: EGFRm=epidermal growth factor receptor mutation; NSCLC=non-small-cell lung cancer; PD-1=programmed cell death protein 1; PD-L1=programmed cell death-ligand 1; TNBC=triple-negative breast cancer; VEGF=vascular endothelial growth factor

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Ivonescimab is an investigational therapy not presently approved by any regulatory authority other than China's National Medical Products Administration (NMPA). Summit Proprietary Information - Do Not Copy or Distribute JPM 2026 Presentation \| 1/202615 Bob Duggan Chairman & Co-Chief Executive Officer Dave Gancarz Chief Business & Strategy Officer Manmeet Soni Chief Operating Officer & Chief Financial Officer Dr. Maky Zanganeh President & Co-Chief Executive Officer Dr. Allen Yang Chief R&D Officer Dr. Fong Chow Chief Biometrics Officer Dr. Urte Gayko Chief Regulatory, Pharmacovigilance & Quality Officer Dr. Jack West VP, Medical Affairs and Thoracic Oncology Expert

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## Exhibit 99.2

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&nbsp;&nbsp;&nbsp;&nbsp;1 Summit Therapeutics Announces Submission of Biologics License Application (BLA) to U.S. FDA Seeking Approval for Ivonescimab in Combination with Chemotherapy in 2L+ Treatment of Patients with EGFRm NSCLC Significant Unmet Need Remains in this Setting Over 14,000 Patients are Eligible for 2L+ Treatment in This Setting in the United States Each Year Summit Enters 2026 with Approximately $710 Million in Cash Miami, Florida, January 12, 2026 – Summit Therapeutics Inc. (NASDAQ: SMMT) ("Summit," "we," or the "Company") today announced that it has submitted a Biologics License Application (BLA) to the U.S. Food and Drug Administration (FDA) seeking approval for ivonescimab, the novel, first-in-class investigational bispecific antibody, in combination with chemotherapy in second-line or later treatment of patients with epidermal growth factor receptor (EGFR)-mutated locally advanced or metastatic non-squamous non-small cell lung cancer (NSCLC). The BLA submission was based on the overall results of the global Phase III HARMONi trial. The BLA was submitted during the fourth quarter of 2025. "This BLA submission, the first for ivonescimab, marks a critical milestone for Summit, our global clinical development plan, and the many patients with EGFRm NSCLC in need of better therapeutics options," stated Robert W. Duggan and Dr. Maky Zanganeh, Co-Chief Executive Officers of Summit. "As we continue to support and expand ivonescimab's rapid development via our growing set of global Phase III trials and clinical collaborations, we look forward to the potential first U.S. approval for ivonescimab in this difficult to treat setting." HARMONi evaluated ivonescimab plus platinum-doublet chemotherapy compared to placebo plus platinum- doublet chemotherapy in patients with EGFR-mutated, locally advanced or metastatic NSCLC who have progressed after treatment with a 3rd generation EGFR tyrosine kinase inhibitor (TKI). This is a clinical setting with a patient population where PD-1 monoclonal antibodies have previously been unsuccessful in Phase III global clinical trials in showing either a progression-free survival (PFS) or overall survival (OS) benefit, the two primary endpoints of this clinical study. Based upon standard review timelines, if the application is accepted as submitted, we anticipate a decision from the agency by the fourth quarter of 2026. Update Regarding Current Financial Position As of December 31, 2025, the company's preliminary unaudited balance of cash, cash equivalents, and short-term investments was approximately $710 million. This amount is preliminary and is subject to completion of financial closing procedures. As a result, this amount may differ from the amount that will be reflected in the Company's consolidated financial statements for the year ended December 31, 2025. About Ivonescimab Ivonescimab, known as SMT112 in Summit's license territories, North America, South America, Europe, the Middle East, Africa, and Japan, and as AK112 outside of Summit's license territories, is a novel, potential first-in-class

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&nbsp;&nbsp;&nbsp;&nbsp;2 investigational bispecific antibody combining the effects of immunotherapy via a blockade of PD-1 with the anti- angiogenesis effects associated with blocking VEGF into a single molecule. By design, ivonescimab displays unique cooperative binding to each of its intended targets with multifold higher affinity to PD-1 when in the presence of VEGF. This is intended to differentiate ivonescimab as there is potentially higher expression (presence) of both PD-1 and VEGF in tumor tissue and the tumor microenvironment (TME) as compared to normal tissue in the body. We believe ivonescimab's specifically engineered tetravalent structure (four binding sites) enables higher avidity (accumulated strength of multiple binding interactions) in the TME (Zhong, et al, SITC, 2023). This tetravalent structure, the intentional novel design of the molecule, and bringing these two targets into a single bispecific antibody with cooperative binding qualities have the potential to direct ivonescimab to the tumor tissue versus healthy tissue. The intent of this design, together with a half-life of 6 to 7 days after the first dose (Zhong, et al, SITC, 2023) increasing to approximately 10 days at steady state dosing, is to improve upon previously established efficacy thresholds, side effects, and safety profiles associated with prior approved drugs to these targets. Ivonescimab was engineered by Akeso Inc. (HKEX Code: 9926.HK) and is currently utilized in multiple Phase III clinical trials. Over 4,000 patients have been treated with ivonescimab in clinical studies globally, and over 60,000 patients when considering those treated in a commercial setting in China, as noted by Akeso. Summit began its clinical development of ivonescimab in NSCLC, commencing enrollment in 2023 in two multiregional Phase III clinical trials, HARMONi and HARMONi-3. In 2025, the Company began enrolling patients in HARMONi-7. Summit expanded its Phase III clinical development program into CRC in the fourth quarter of 2025 by initiating enrollment in HARMONi-GI3. HARMONi is a Phase III clinical trial which intends to evaluate ivonescimab combined with chemotherapy compared to placebo plus chemotherapy in patients with EGFR-mutated, locally advanced or metastatic non- squamous NSCLC who were previously treated with a 3rd generation EGFR TKI (e.g., osimertinib). Detailed results of the study were provided in September 2025, and a Biologics License Application (BLA) was submitted to the United States Food and Drug Administration (FDA) for marketing authorization in the fourth quarter of 2025. HARMONi-3 is a Phase III clinical trial, which is intended to evaluate ivonescimab combined with chemotherapy compared to pembrolizumab combined with chemotherapy in patients with first-line metastatic, squamous or non- squamous NSCLC, irrespective of PD-L1 expression. HARMONi-7 is a Phase III clinical trial which is intended to evaluate ivonescimab monotherapy compared to pembrolizumab monotherapy in patients with first-line metastatic NSCLC whose tumors have high PD-L1 expression. HARMONi-GI3 is a Phase III clinical trial evaluating ivonescimab in combination with chemotherapy compared with bevacizumab plus chemotherapy in patients with first-line unresectable metastatic CRC. In addition, Akeso has recently had positive read-outs in three single-region (China), randomized Phase III clinical trials, HARMONi-A, HARMONi-2, and HARMONi-6, for ivonescimab in NSCLC, including a statistically significant overall survival benefit in HARMONi-A with a manageable safety profile in each study. HARMONi-A was a Phase III clinical trial which evaluated ivonescimab combined with chemotherapy compared to placebo plus chemotherapy in patients with EGFR-mutated, locally advanced or metastatic non-squamous NSCLC who have progressed after treatment with an EGFR TKI. HARMONi-2 is a Phase III clinical trial evaluating monotherapy ivonescimab against monotherapy pembrolizumab in patients with locally advanced or metastatic NSCLC whose tumors have positive PD-L1 expression.

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&nbsp;&nbsp;&nbsp;&nbsp;3 HARMONi-6 is a Phase III clinical trial evaluating ivonescimab in combination with platinum-based chemotherapy compared with tislelizumab, an anti-PD-1 antibody, in combination with platinum-based chemotherapy in patients with locally advanced or metastatic squamous NSCLC, irrespective of PD-L1 expression. Akeso is actively conducting multiple Phase III clinical studies in settings outside of NSCLC, including biliary tract cancer, colorectal cancer, breast cancer, pancreatic cancer, small cell lung cancer, and head and neck cancer. Ivonescimab is an investigational therapy that is not approved by any regulatory authority in Summit's license territories, including the United States and Europe. Ivonescimab was initially approved for marketing authorization in China in May 2024. Ivonescimab was granted Fast Track designation by the US Food & Drug Administration (FDA) for the HARMONi clinical trial setting. About Summit Therapeutics Summit Therapeutics Inc. is a biopharmaceutical oncology 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. Summit was founded in 2003 and our shares are listed on the Nasdaq Global Market (symbol "SMMT"). We are headquartered in Miami, Florida, and we have additional offices in Menlo Park, California, and Oxford, UK. For more information, please visit https://www.smmttx.com and follow us on X @SMMT_TX. Contact Summit Investor Relations: Dave Gancarz Chief Business & Strategy Officer Nathan LiaBraaten Senior Director, Investor Relations investors@smmttx.com media@smmttx.com Summit Forward-looking Statements Any statements in this press release about the Company's future expectations, plans and prospects, including but not limited to, statements about the clinical and preclinical development of the Company's product candidates, entry into and actions related to the Company's partnership with Akeso Inc., the intended use of the net proceeds from the private placements, the Company's anticipated spending and cash runway, the therapeutic potential of the Company's product candidates, the potential commercialization of the Company's product candidates, the timing of initiation, completion and availability of data from clinical trials, the potential submission of applications for marketing approvals, the expected timing of BLA submissions or FDA decisions, potential acquisitions, statements about the previously disclosed At-The-Market equity offering program ("ATM Program"), the expected proceeds and uses thereof, the Company's estimates regarding stock-based compensation, and other statements containing the words "anticipate," "believe," "continue," "could," "estimate," "expect," "intend," "may," "plan," "potential," "predict," "project," "should," "target," "would," and similar expressions, constitute forward-looking statements within the meaning of The Private Securities Litigation Reform Act of 1995. Actual results may differ materially from those indicated by such forward-looking statements as a result of various important factors, including the Company's ability to sell shares of our common stock under the ATM Program, the conditions affecting the capital markets, general economic, industry, or political conditions, including the effects of geopolitical

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&nbsp;&nbsp;&nbsp;&nbsp;4 developments, domestic and foreign trade policies, and monetary policies, the results of our evaluation of the underlying data in connection with the development and commercialization activities for ivonescimab, the outcome of discussions with regulatory authorities, including the Food and Drug Administration, the uncertainties inherent in the initiation of future clinical trials, availability and timing of data from ongoing and future clinical trials, the results of such trials, and their success, global public health crises, that may affect timing and status of our clinical trials and operations, whether preliminary results from a clinical trial will be predictive of the final results of that trial or whether results of early clinical trials or preclinical studies will be indicative of the results of later clinical trials, whether business development opportunities to expand the Company's pipeline of drug candidates, including without limitation, through potential acquisitions of, and/or collaborations with, other entities occur, expectations for regulatory approvals, laws and regulations affecting government contracts and funding awards, availability of funding sufficient for the Company's foreseeable and unforeseeable operating expenses and capital expenditure requirements and other factors discussed in the "Risk Factors" and "Management's Discussion and Analysis of Financial Condition and Results of Operations" sections of filings that the Company makes with the Securities and Exchange Commission. Summit defines a "positive study" as a clinical study that with one or more prespecified primary endpoints in which one of those endpoints achieves a statistically significant benefit according to the protocol or statistical analysis plan. Any change to our ongoing trials could cause delays, affect our future expenses, and add uncertainty to our commercialization efforts, as well as to affect the likelihood of the successful completion of clinical development of ivonescimab. Accordingly, readers should not place undue reliance on forward-looking statements or information. In addition, any forward-looking statements included in this press release represent the Company's views only as of the date of this release and should not be relied upon as representing the Company's views as of any subsequent date. The Company specifically disclaims any obligation to update any forward-looking statements included in this press release. Summit Therapeutics and the Summit Therapeutics logo are trademarks of Summit Therapeutics Inc. and/or its affiliates Copyright 2026, Summit Therapeutics Inc. All Rights Reserved

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## Exhibit 99.3

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&nbsp;&nbsp;&nbsp;&nbsp;1 Summit Therapeutics Announces Clinical Trial Collaboration with GSK to Evaluate Ivonescimab in Combination with GSK's B7-H3 Antibody Drug Conjugate (ADC) Summit to Advance Development Opportunities of Ivonescimab with GSK's Novel B7-H3 risvutatug rezetecan Multiple Solid Tumor Settings to Be Pursued with Clinical Trials Expected to Start in Mid-2026 Miami, Florida, January 12, 2026 – Summit Therapeutics Inc. (NASDAQ: SMMT) today announced it has entered into a clinical trial collaboration with GSK plc ("GSK", LSE/NYSE: GSK) to evaluate ivonescimab, a novel, investigational PD-1 / VEGF bispecific antibody, in combination with risvutatug rezetecan (also known as GSK'227), GSK's novel investigational B7-H3 targeting antibody drug conjugate (ADC), across multiple solid tumor settings, including small cell lung cancer (SCLC). "We believe exploring new mechanisms and combinations with the potential to surpass current options for patients and physicians will have the most profound impact on those battling the toughest cancer challenges today," stated Robert W. Duggan and Dr. Maky Zanganeh, Co-Chief Executive Officers of Summit. "With the goal of accelerating development of ivonescimab in multiple solid tumors, this collaboration enables us to swiftly advance ivonescimab and expand Summit's combination strategy." The intent of this agreement is to investigate the combination potential of ivonescimab and risvutatug rezetecan in multiple solid tumor environments to determine the safety profile and potential anti-tumor effects. Under the terms of the agreement, Summit will supply ivonescimab for the planned study, while GSK will manage the day-to-day clinical operations of the study. Each party will maintain rights to their respective products, and the agreement is mutually non-exclusive. The study is expected to begin dosing patients in mid-2026. About risvutatug rezetecan Risvutatug rezetecan, also known as GSK'227, is a novel investigational B7-H3-targeted antibody-drug conjugate composed of a fully human anti-B7-H3 monoclonal antibody covalently linked to a topoisomerase inhibitor payload. GSK acquired exclusive worldwide rights (excluding China's mainland, Hong Kong, Macau, and Taiwan) from Hansoh Pharma to progress clinical development and commercialisation of risvutatug rezetecan. GSK's global phase III trial for risvutatug rezetecan in relapsed ES-SCLC began in August 2025. About Ivonescimab Ivonescimab, known as SMT112 in Summit's license territories, North America, South America, Europe, the Middle East, Africa, and Japan, and as AK112 outside of Summit's license territories, is a novel, potential first-in-class investigational bispecific antibody combining the effects of immunotherapy via a blockade of PD-1 with the anti- angiogenesis effects associated with blocking VEGF into a single molecule. By design, ivonescimab displays unique cooperative binding to each of its intended targets with multifold higher affinity to PD-1 when in the presence of VEGF. This is intended to differentiate ivonescimab as there is potentially higher expression (presence) of both PD-1 and VEGF in tumor tissue and the tumor microenvironment (TME) as compared to normal tissue in the body. We believe ivonescimab's specifically engineered tetravalent structure (four binding sites) enables higher avidity

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![](a2026_prx0112xannounceme002.jpg)

&nbsp;&nbsp;&nbsp;&nbsp;2 (accumulated strength of multiple binding interactions) in the TME (Zhong, et al, SITC, 2023). This tetravalent structure, the intentional novel design of the molecule, and bringing these two targets into a single bispecific antibody with cooperative binding qualities have the potential to direct ivonescimab to the tumor tissue versus healthy tissue. The intent of this design, together with a half-life of 6 to 7 days after the first dose (Zhong, et al, SITC, 2023) increasing to approximately 10 days at steady state dosing, is to improve upon previously established efficacy thresholds, side effects, and safety profiles associated with prior approved drugs to these targets. Ivonescimab was engineered by Akeso Inc. (HKEX Code: 9926.HK) and is currently utilized in multiple Phase III clinical trials. Over 4,000 patients have been treated with ivonescimab in clinical studies globally, and over 60,000 patients when considering those treated in a commercial setting in China, as noted by Akeso. Summit began its clinical development of ivonescimab in NSCLC, commencing enrollment in 2023 in two multiregional Phase III clinical trials, HARMONi and HARMONi-3. In 2025, the Company began enrolling patients in HARMONi-7. Summit expanded its Phase III clinical development program into CRC in the fourth quarter of 2025 by initiating enrollment in HARMONi-GI3. HARMONi is a Phase III clinical trial which intends to evaluate ivonescimab combined with chemotherapy compared to placebo plus chemotherapy in patients with EGFR-mutated, locally advanced or metastatic non- squamous NSCLC who were previously treated with a 3rd generation EGFR TKI (e.g., osimertinib). Detailed results of the study were provided in September 2025, and a Biologics License Application (BLA) was submitted to the United States Food and Drug Administration (FDA) for marketing authorization in the fourth quarter of 2025. HARMONi-3 is a Phase III clinical trial, which is intended to evaluate ivonescimab combined with chemotherapy compared to pembrolizumab combined with chemotherapy in patients with first-line metastatic, squamous or non- squamous NSCLC, irrespective of PD-L1 expression. HARMONi-7 is a Phase III clinical trial which is intended to evaluate ivonescimab monotherapy compared to pembrolizumab monotherapy in patients with first-line metastatic NSCLC whose tumors have high PD-L1 expression. HARMONi-GI3 is a Phase III clinical trial evaluating ivonescimab in combination with chemotherapy compared with bevacizumab plus chemotherapy in patients with first-line unresectable metastatic CRC. In addition, Akeso has recently had positive read-outs in three single-region (China), randomized Phase III clinical trials, HARMONi-A, HARMONi-2, and HARMONi-6, for ivonescimab in NSCLC, including a statistically significant overall survival benefit in HARMONi-A with a manageable safety profile in each study. HARMONi-A was a Phase III clinical trial which evaluated ivonescimab combined with chemotherapy compared to placebo plus chemotherapy in patients with EGFR-mutated, locally advanced or metastatic non-squamous NSCLC who have progressed after treatment with an EGFR TKI. HARMONi-2 is a Phase III clinical trial evaluating monotherapy ivonescimab against monotherapy pembrolizumab in patients with locally advanced or metastatic NSCLC whose tumors have positive PD-L1 expression. HARMONi-6 is a Phase III clinical trial evaluating ivonescimab in combination with platinum-based chemotherapy compared with tislelizumab, an anti-PD-1 antibody, in combination with platinum-based chemotherapy in patients with locally advanced or metastatic squamous NSCLC, irrespective of PD-L1 expression. Akeso is actively conducting multiple Phase III clinical studies in settings outside of NSCLC, including biliary tract cancer, colorectal cancer, breast cancer, pancreatic cancer, small cell lung cancer, and head and neck cancer.

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&nbsp;&nbsp;&nbsp;&nbsp;3 Ivonescimab is an investigational therapy that is not approved by any regulatory authority in Summit's license territories, including the United States and Europe. Ivonescimab was initially approved for marketing authorization in China in May 2024. Ivonescimab was granted Fast Track designation by the US Food & Drug Administration (FDA) for the HARMONi clinical trial setting. About GSK GSK is a global biopharma company with a purpose to unite science, technology, and talent to get ahead of disease together. Find out more at gsk.com. About Summit Therapeutics Summit Therapeutics Inc. is a biopharmaceutical oncology 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. Summit was founded in 2003 and our shares are listed on the Nasdaq Global Market (symbol "SMMT"). We are headquartered in Miami, Florida, and we have additional offices in Menlo Park, California, and Oxford, UK. For more information, please visit https://www.smmttx.com and follow us on X @SMMT_TX. Contact Summit Investor Relations: Dave Gancarz Chief Business & Strategy Officer Nathan LiaBraaten Senior Director, Investor Relations investors@smmttx.com media@smmttx.com Summit Forward-looking Statements Any statements in this press release about the Company's future expectations, plans and prospects, including but not limited to, statements about the clinical and preclinical development of the Company's product candidates, entry into and actions related to the Company's partnership with Akeso Inc., the intended use of the net proceeds from the private placements, the Company's anticipated spending and cash runway, the therapeutic potential of the Company's product candidates, the potential commercialization of the Company's product candidates, the timing of initiation, completion and availability of data from clinical trials, the potential submission of applications for marketing approvals, the expected timing of BLA submissions or FDA decisions, potential acquisitions, statements about the previously disclosed At-The-Market equity offering program ("ATM Program"), the expected proceeds and uses thereof, the Company's estimates regarding stock-based compensation, and other statements containing the words "anticipate," "believe," "continue," "could," "estimate," "expect," "intend," "may," "plan," "potential," "predict," "project," "should," "target," "would," and similar expressions, constitute forward-looking statements within the meaning of The Private Securities Litigation Reform Act of 1995. Actual results may differ materially from those indicated by such forward-looking statements as a result of various important factors, including the Company's ability to sell shares of our common stock under the ATM Program, the conditions affecting the capital markets, general economic, industry, or political conditions, including the effects of geopolitical developments, domestic and foreign trade policies, and monetary policies, the results of our evaluation of the underlying data in connection with the development and commercialization activities for ivonescimab, the outcome

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&nbsp;&nbsp;&nbsp;&nbsp;4 of discussions with regulatory authorities, including the Food and Drug Administration, the uncertainties inherent in the initiation of future clinical trials, availability and timing of data from ongoing and future clinical trials, the results of such trials, and their success, global public health crises, that may affect timing and status of our clinical trials and operations, whether preliminary results from a clinical trial will be predictive of the final results of that trial or whether results of early clinical trials or preclinical studies will be indicative of the results of later clinical trials, whether business development opportunities to expand the Company's pipeline of drug candidates, including without limitation, through potential acquisitions of, and/or collaborations with, other entities occur, expectations for regulatory approvals, laws and regulations affecting government contracts and funding awards, availability of funding sufficient for the Company's foreseeable and unforeseeable operating expenses and capital expenditure requirements and other factors discussed in the "Risk Factors" and "Management's Discussion and Analysis of Financial Condition and Results of Operations" sections of filings that the Company makes with the Securities and Exchange Commission. Summit defines a "positive study" as a clinical study that with one or more prespecified primary endpoints in which one of those endpoints achieves a statistically significant benefit according to the protocol or statistical analysis plan. Any change to our ongoing trials could cause delays, affect our future expenses, and add uncertainty to our commercialization efforts, as well as to affect the likelihood of the successful completion of clinical development of ivonescimab. Accordingly, readers should not place undue reliance on forward-looking statements or information. In addition, any forward-looking statements included in this press release represent the Company's views only as of the date of this release and should not be relied upon as representing the Company's views as of any subsequent date. The Company specifically disclaims any obligation to update any forward-looking statements included in this press release. Summit Therapeutics and the Summit Therapeutics logo are trademarks of Summit Therapeutics Inc. and/or its affiliates Copyright 2026, Summit Therapeutics Inc. All Rights Reserved

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