SMMT / Summit Therapeutics Inc. - Pengajuan SECLaporan Tahunan, Pernyataan Proksi

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 11, 2025

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 11, 2025 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commissio

J.P. Morgan

424B5 Table of Contents Filed pursuant to Rule 424(b)(5) Registration No. 333-277169 Prospectus supplement (To prospectus dated February 27, 2024) Up to $360,000,000 Common stock We have previously entered into a distribution agreement dated May 13, 2024 (the “Original Distribution Agreement”) with J.P. Morgan Securities LLC (which we refer to as the “Sales Agent”), relating to shares of our commo

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2025 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-36866 Summit The

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 11, 2025 Summit Therapeuti

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 11, 2025 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commissio

Summit Therapeutics Reports Financial Results and Operational Progress for the Second Quarter Ended June 30, 2025 Ivonescimab in Combination with Chemotherapy Showed Statistically Significant and Clinically Meaningful Improvement in Progression-Free

a2025prx0811xq22025earn Summit Therapeutics Reports Financial Results and Operational Progress for the Second Quarter Ended June 30, 2025 Ivonescimab in Combination with Chemotherapy Showed Statistically Significant and Clinically Meaningful Improvement in Progression-Free Survival in Global Phase III HARMONi Trial Evaluating Patients with EGFRm NSCLC after EGFR TKI Therapy; Positive Trend Observe

, by and between Summit Therapeutics Inc. and Ascendis Pharma, Inc.

paloaltosub-sublease Certain confidential information contained in this document, marked by [**], has been omitted pursuant to Item 601(b)(10)(iv) of Regulation S-K because it is both (i) not material and (ii) the type of information that the registrant treats as private or confidential.

Amendment to Distribution Agreement, dated August 11, 2025, by and between Summit Therapeutics Inc. and J.P. Morgan Securities LLC

EX-1.2 Exhibit 1.2 SUMMIT THERAPEUTICS INC. AMENDMENT NO. 1 TO DISTRIBUTION AGREEMENT August 11, 2025 J.P. Morgan Securities LLC 383 Madison Avenue New York, NY 10179 Ladies and Gentlemen: Reference is made to the Distribution Agreement, dated May 13, 2024 (the “Original Agreement”), by and between Summit Therapeutics Inc., a Delaware corporation (the “Company”), and J.P. Morgan Securities LLC (th

Distribution Agreement, dated May 13, 2024, by and between Summit Therapeutics Inc. and J.P. Morgan Securities LLC

EX-1.1 Exhibit 1.1 DISTRIBUTION AGREEMENT May 13, 2024 J.P. Morgan Securities LLC 383 Madison Avenue New York, New York 10179 Ladies and Gentlemen: Summit Therapeutics Inc., a Delaware corporation (the “Company”), confirms its agreement with J.P. Morgan Securities LLC, as agent and/or principal under any Terms Agreement (as defined in Section 1(a) below) (“you” or the “Agent”), with respect to the

Entry into a Material Definitive Agreement

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of Earliest Event Reported): June 16, 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

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of Earliest Event Reported): June 12, 2025

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of Earliest Event Reported): June 12, 2025 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commission

1 Ivonescimab Plus Chemotherapy Demonstrates Statistically Significant and Clinically Meaningful Improvement in Progression-Free Survival in Patients with EGFR- Mutant Non-Small Cell Lung Cancer after EGFR TKI Therapy in Global Study Consistent Resul

1 Ivonescimab Plus Chemotherapy Demonstrates Statistically Significant and Clinically Meaningful Improvement in Progression-Free Survival in Patients with EGFR- Mutant Non-Small Cell Lung Cancer after EGFR TKI Therapy in Global Study Consistent Results Noted between Single Region HARMONi-A and Multiregional HARMONi Studies; Favorable Trends in Sub-Populations from North America and China for Both Primary Endpoints Were Observed Ivonescimab in Combination with Chemotherapy Reduces the Risk of Disease Progression or Death by 48% Compared to Chemotherapy Alone; Positive Overall Survival Trend Observed with Hazard Ratio of 0.

Financial Statements and Exhibits, Other Events

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): May 30, 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 F

Form of Option Award under 2020 Stock Incentive Plan

Exhibit 99.2 Summit Therapeutics Inc. STOCK OPTION AGREEMENT Summit Therapeutics Inc. (the “Company”) hereby grants the following stock option pursuant to its 2020 Stock Incentive Plan. The terms and conditions attached hereto are also a part hereof. Notice of Grant Name of optionee (the “Participant”) Grant Date: Incentive Stock Option or Nonstatutory Stock Option: Number of shares of the Company

Form of Stock Option Inducement Grant Notice and Option Agreement Inducement Grant

Exhibit 99.4 SUMMIT THERAPEUTICS INC. STOCK OPTION INDUCEMENT GRANT Summit Therapeutics Inc. (the “Company”) hereby grants you an option (the “Option”) to purchase shares of the Company’s common stock (the “Common Stock”). This Option has been granted as an “inducement” award under NASDAQ Marketplace Rules. Accordingly, the Option has been granted outside of the Company’s existing equity compensat

As filed with the Securities and Exchange Commission on May 19, 2025

As filed with the Securities and Exchange Commission on May 19, 2025 Registration No.

Filing Fee Table

Calculation of Filing Fee Tables S-8 Summit Therapeutics Inc. Table 1: Newly Registered Securities Security Type Security Class Title Fee Calculation Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee 1 Equity Common Stock, $0.01 par value per share Other 3,338,428 $ 22.55 $ 75,281,551.40 0.0001531 $ 11,525.61 2 Equi

Regulation FD Disclosure, Financial Statements and Exhibits, Results of Operations and Financial Condition

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): May 1, 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 Fi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2025 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-36866 Summit Th

Summit Therapeutics Q1 2025 Earnings Call May 1, 2025 4:30pm ET 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 an

Summit Therapeutics Q1 2025 Earnings Call May 1, 2025 4:30pm ET 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.

1 Summit Therapeutics Reports Financial Results and Operational Progress for the First Quarter Ended March 31, 2025 Ivonescimab in Combination with Chemotherapy Achieves Statistically Significant Superiority in PFS vs. Tislelizumab (PD-1 Inhibitor) P

1 Summit Therapeutics Reports Financial Results and Operational Progress for the First Quarter Ended March 31, 2025 Ivonescimab in Combination with Chemotherapy Achieves Statistically Significant Superiority in PFS vs.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) Information Required in Proxy Statement Schedule 14a Information Proxy Statement Pursuant to Section 14(a) of The Securities Exchange Act of 1934 (Ame

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) Information Required in Proxy Statement Schedule 14a Information Proxy Statement Pursuant to Section 14(a) of The Securities Exchange Act of 1934 (Amendment No.) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confiden

1 Interim Overall Survival Analysis Requested from Chinese Health Authorities Shows a Clinically Meaningful, Positive Trend Favoring Ivonescimab Compared to Pembrolizumab in PD-L1 Positive Advanced NSCLC from HARMONi-2 Study Conducted by Akeso in Chi

1 Interim Overall Survival Analysis Requested from Chinese Health Authorities Shows a Clinically Meaningful, Positive Trend Favoring Ivonescimab Compared to Pembrolizumab in PD-L1 Positive Advanced NSCLC from HARMONi-2 Study Conducted by Akeso in China Interim Analysis of HARMONi-2 Shows an Overall Survival Hazard Ratio of 0.

Financial Statements and Exhibits, Other Events

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): April 25, 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

Financial Statements and Exhibits, Other Events

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): April 23, 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

1 Ivonescimab in Combination with Chemotherapy Achieves Statistically Significant Superiority in PFS vs. Tislelizumab (PD-1 Inhibitor) Plus Chemotherapy in 1L Treatment of Patients with Squamous NSCLC in HARMONi-6 Study Conducted by Akeso in China Iv

a2025prx0423xivonescima 1 Ivonescimab in Combination with Chemotherapy Achieves Statistically Significant Superiority in PFS vs.

Summit Therapeutics Reports Financial Results and Operational Progress for the Fourth Quarter and Twelve Months Ended December 31, 2024 Clinical Trial Collaboration with Pfizer Evaluating Ivonescimab in Combination with Several Vedotin ADCs in Unique

pressreleaseq4december20 Summit Therapeutics Reports Financial Results and Operational Progress for the Fourth Quarter and Twelve Months Ended December 31, 2024 Clinical Trial Collaboration with Pfizer Evaluating Ivonescimab in Combination with Several Vedotin ADCs in Unique Solid Tumor Settings; Clinical Trials Expected to Start Mid-2025 Enrollment Completed for Global, Multi-Regional Phase III H

List of Significant Subsidiaries

Exhibit 21.1 SUBSIDIARIES OF THE REGISTRANT Name of Subsidiary Jurisdiction of incorporation or organization Summit Therapeutics Sub Inc. Delaware, USA Summit International Holdings Limited (Cayman Islands) Cayman Islands Summit Therapeutics Global LLC Delaware, USA Summit (Oxford) Limited England and Wales Summit Therapeutics Limited England and Wales Discuva Limited England and Wales Summit Ther

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2024 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 001-36866 Summit Therape

Code of Business Conduct and Ethics of Summit Therapeutics Inc

sum-ex14120241231xcodeo SUMMIT THERAPEUTICS INC. CODE OF BUSINESS CONDUCT AND ETHICS Summit Therapeutics, Inc., and its affiliates and subsidiaries (the “Company” or “Summit”) is committed to creating an environment where we are able to do our best work while maintaining the highest standards of business conduct and ethics. This Code of Business Conduct and Ethics (the “Code”) sets forth legal and

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): February 24, 2025

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): February 24, 2025 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commiss

Summit Therapeutics Q4 & YE 2024 Earnings Call February 24, 2025 9:00am ET 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

Summit Therapeutics Q4 & YE 2024 Earnings Call February 24, 2025 9:00am ET 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.

nsider Trading Policy

SUMMIT THERAPEUTICS INC. INSIDER TRADING POLICY 1.0 Purpose The federal securities laws prohibit any member of the Board of Directors (“Director”), Officer (as defined in Rule 16a-1(f) under the Securities Exchange Act of 1934 (the “Exchange Act”)) or employee of Summit Therapeutics Inc. (together with its affiliates and subsidiaries, “Summit” or the “Company”) from purchasing or selling the Compa

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Other Events

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): January 22, 2025 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commissi

Regulation FD Disclosure, Financial Statements and Exhibits, Results of Operations and Financial Condition

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): January 13, 2025 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commissi

43rd Annual J.P. Morgan Healthcare Conference January 13, 2025 Mission Vision BOB DUGGAN, Chairman & CEO DR. MAKY ZANGANEH, CEO & President Forward Looking Statement Any statements in this presentation about the Company’s future expectations, plans a

jpm2025final8-k 43rd Annual J.P. Morgan Healthcare Conference January 13, 2025 Mission Vision BOB DUGGAN, Chairman & CEO DR. MAKY ZANGANEH, CEO & President 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 candida

*****

January 6, 2025 Via EDGAR United States Securities and Exchange Commission Division of Corporation Finance Office of Life Sciences 100 F Street, N.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2024 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-36866 Summi

Summit Therapeutics Reports Operational Progress and Financial Results for the Third Quarter and Nine Months Ended September 30, 2024 Ivonescimab Monotherapy Became First Drug to Achieve Clinically Meaningful Benefit over Pembrolizumab Monotherapy in

EX-99.1 2 a2024prx1030xq32024earn.htm EX-99.1 Summit Therapeutics Reports Operational Progress and Financial Results for the Third Quarter and Nine Months Ended September 30, 2024 Ivonescimab Monotherapy Became First Drug to Achieve Clinically Meaningful Benefit over Pembrolizumab Monotherapy in a Phase III Randomized Clinical Trial in NSCLC, HARMONi-2, Reducing Risk of Disease Progression or Deat

Summit Therapeutics Q3 2024 Earnings Call October 30, 2024 9:00am ET Forward Looking Statement 2 Any statements in this presentation about the Company’s future expectations, plans and prospects, including but not limited to, statements about the clin

Summit Therapeutics Q3 2024 Earnings Call October 30, 2024 9:00am ET Forward Looking Statement 2 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.

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): October 30, 2024

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): October 30, 2024 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commissi

Filing Fee Table

Exhibit 107 Calculation of Filing Fee Tables Form S-3 (Form Type) Summit Therapeutics Inc.

As filed with the Securities and Exchange Commission on September 19, 2024

S-3ASR Table of Contents As filed with the Securities and Exchange Commission on September 19, 2024 Registration No.

SMMT / Summit Therapeutics Inc. / DUGGAN ROBERT W - SC 13D/A Activist Investment

SC 13D/A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D (Rule 13d-101) INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO § 240.13d-1(a) AND AMENDMENTS THERETO FILED PURSUANT TO § 240.13d-2(a) (Amendment No. 9)1 Summit Therapeutics Inc. (Name of Issuer) Common Stock, par value $0.01 per share (Title of Class of Securities) 86627T108 (CUSIP Number) ADAM

Regulation FD Disclosure, Entry into a Material Definitive Agreement, Unregistered Sales of Equity Securities

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): September 11, 2024 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commis

Summit Therapeutics Raises $235 Million Fundraise Led by Insiders & Leading Biopharma Institutional Investors in a Private Placement $235 Million in Net Proceeds Raised at Yesterday’s Closing Price of $22.70

EX-99.1 Exhibit 99.1 Summit Therapeutics Raises $235 Million Fundraise Led by Insiders & Leading Biopharma Institutional Investors in a Private Placement $235 Million in Net Proceeds Raised at Yesterday’s Closing Price of $22.70 Miami, Florida, September 12, 2024 – Summit Therapeutics Inc. (NASDAQ: SMMT) (“Summit,” “we,” or the “Company”) today announced that the Company accepted offers from multi

Form of Registration Rights Agreement

Exhibit 10.2 REGISTRATION RIGHTS AGREEMENT THIS REGISTRATION RIGHTS AGREEMENT (this “Agreement”), dated as of September 11, 2024, is entered into by and among Summit Therapeutics Inc., a Delaware corporation (the “Company”), and the several investors signatory hereto (individually as an “Investor” and collectively together with their respective permitted assigns, the “Investors”). Capitalized term

Form of Securities Purchase Agreement

EX-10.1 Exhibit 10.1 SECURITIES PURCHASE AGREEMENT This SECURITIES PURCHASE AGREEMENT (this “Agreement”) is dated as of September 11, 2024, by and among Summit Therapeutics Inc., a Delaware corporation (the “Company”), and each of the entities listed on Exhibit A attached to this Agreement (each, an “Investor” and together, the “Investors”). WHEREAS, the Company and the Investors are executing and

Changli Wang | A Phase II Study of Perioperative Ivonescimab Alone or Combined with Chemotherapy in Resectable Non-Small Cell Lung Cancer 1 A Phase II Study of Perioperative Ivonescimab Alone or Combined with Chemotherapy in Resectable Non-Small Cell

Changli Wang | A Phase II Study of Perioperative Ivonescimab Alone or Combined with Chemotherapy in Resectable Non-Small Cell Lung Cancer 1 A Phase II Study of Perioperative Ivonescimab Alone or Combined with Chemotherapy in Resectable Non-Small Cell Lung Cancer Changli Wang1, Xiaoliang Zhao1, Lianmin Zhang1, Dongsheng Yue1, Zhenfa Zhang1, Meng Wang1, Ziqiang Tian2, Shengguang Wang1, Chong Pang1, Bin Zhang1, Qiang Zhang1, Wei Wei1, Yu Zhang1, Xiaofei Wang1, Yue Li1, Huilai Lv2, Yu Xia3, Baiyong Li3, Zhongmin Maxwell Wang3, Wenting Li3 1.

Regulation FD Disclosure, Financial Statements and Exhibits, Other Events

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): September 8, 2024 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commiss

Summit Therapeutics Update Call from WCLC September 9, 2024 Forward-Looking Statements 2 Any statements in this presentation about the Company’s future expectations, plans and prospects, including but not limited to, statements about the clinical and

Summit Therapeutics Update Call from WCLC September 9, 2024 Forward-Looking Statements 2 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.

Phase 3 Study of Ivonescimab (AK112) vs. Pembrolizumab as First-line Treatment for PD-L1-positive Advanced NSCLC: HARMONi-2 C. Zhou1,2, J. Chen3, L. Wu3, L. Wang1, A. Xiong1, B. Liu4, J. Yao5, H. Zhong6, J. Li7, Y. Cheng8, Y. Sun9, H. Ge10, Q. Shi11,

Phase 3 Study of Ivonescimab (AK112) vs. Pembrolizumab as First-line Treatment for PD-L1-positive Advanced NSCLC: HARMONi-2 C. Zhou1,2, J. Chen3, L. Wu3, L. Wang1, A. Xiong1, B. Liu4, J. Yao5, H. Zhong6, J. Li7, Y. Cheng8, Y. Sun9, H. Ge10, Q. Shi11, M. Zhou12, Z. Han13, J. Wang14, Q. Bu15, Y. Zhao16, J. Chen17, J. Yang18, M. Xia18 1Shanghai Pulmonary Hospital, Tongji University School of Medicine

1 Ivonescimab Monotherapy Reduced the Risk of Disease Progression or Death by 49% Compared to Pembrolizumab Monotherapy in First-Line Treatment of Patients with PD-L1 Positive Advanced NSCLC in China Summit to Initiate HARMONi-7, a Phase III Trial in

1 Ivonescimab Monotherapy Reduced the Risk of Disease Progression or Death by 49% Compared to Pembrolizumab Monotherapy in First-Line Treatment of Patients with PD-L1 Positive Advanced NSCLC in China Summit to Initiate HARMONi-7, a Phase III Trial in First-Line PD-L1 High, Advanced NSCLC, in Early 2025 Ivonescimab Is the First Drug to Achieve Clinically Meaningful Benefit over Pembrolizumab in a Randomized Phase III Clinical Trial in NSCLC Median PFS of 11.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2024 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-36866 Summit The

Amendment No. 2 to Collaboration and License Agreement Amendment, dated June 3,

Certain confidential information obtained in this document, marked by [**], has been omitted pursuant to Item 601(b)(10)(iv) of Regulation S-K because it is both (i) not material and (ii) the type of information that the registrant treats as private or confidential.

As filed with the Securities and Exchange Commission on August 6, 2024

Table of Contents As filed with the Securities and Exchange Commission on August 6, 2024 Registration No.

Sublease, dated June 27, 2024, by and between Summit Therapeutics Inc. and Genius 24C Inc. (incorporated by reference to Exhibit 10.6 of the Company’s Quarterly Report on 10-Q (File No. 001-36866), filed with the Securities and Exchange Commission on August 6, 2024)

Certain confidential information obtained in this document, marked by [**], has been omitted pursuant to Item 601(b)(10)(iv) of Regulation S-K because it is both (i) not material and (ii) the type of information that the registrant treats as private or confidential.

Summit Therapeutics Reports Financial Results and Operational Progress for the Second Quarter and Six Months Ended June 30, 2024 Ivonescimab Monotherapy Achieved Statistically Significant & Clinically Meaningful Improvement over Pembrolizumab Monothe

Summit Therapeutics Reports Financial Results and Operational Progress for the Second Quarter and Six Months Ended June 30, 2024 Ivonescimab Monotherapy Achieved Statistically Significant & Clinically Meaningful Improvement over Pembrolizumab Monotherapy Head-to-Head in HARMONi-2 Phase III Trial in 1L Advanced NSCLC Positive HARMONi-A Data Featured at ASCO and Published in JAMA Supporting Ivonesci

, by and between Summit Therapeutics Inc.

Certain confidential information obtained in this document, marked by [**], has been omitted pursuant to Item 601(b)(10)(iv) of Regulation S-K because it is both (i) not material and (ii) the type of information that the registrant treats as private or confidential.

Filing Fee Table

EX-FILING FEES Exhibit 107 Calculation of Filing Fee Tables Form S-3 (Form Type) Summit Therapeutics Inc.

Summit Therapeutics Q2 2024 Earnings Call August 6, 2024 9:00am ET Forward Looking Statement 2 Any statements in this presentation about the Company’s future expectations, plans and prospects, including but not limited to, statements about the clinic

Summit Therapeutics Q2 2024 Earnings Call August 6, 2024 9:00am ET Forward Looking Statement 2 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.

Third Amendment to Sublease, dated August 2, 2024, by and between Summit Therapeutics Sub, Inc. and Zanganeh & Associates Inc.

Certain confidential information obtained in this document, marked by [**], has been omitted pursuant to Item 601(b)(10)(iv) of Regulation S-K because it is both (i) not material and (ii) the type of information that the registrant treats as private or confidential.

Regulation FD Disclosure, Financial Statements and Exhibits, Results of Operations and Financial Condition

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 6, 2024 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commission

1 Summit Therapeutics Appoints Jeff Huber, Transformational Google and GRAIL Executive, to its Board of Directors Miami, Florida, June 27, 2024 – Summit Therapeutics Inc. (NASDAQ: SMMT) (“Summit,” “we,” or the “Company”) today announced that Jeff Hub

1 Summit Therapeutics Appoints Jeff Huber, Transformational Google and GRAIL Executive, to its Board of Directors Miami, Florida, June 27, 2024 – Summit Therapeutics Inc.

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Entry into a Material Definitive Agreement, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of Earliest Event Reported): June 27, 2024 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commission

Current Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of Earliest Event Reported): June 12, 2024 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commission

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) Information Required in Proxy Statement Schedule 14a Information Proxy Statement Pursuant to Section 14(a) of The Securities Exchange Act of 1934 (Ame

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) Information Required in Proxy Statement Schedule 14a Information Proxy Statement Pursuant to Section 14(a) of The Securities Exchange Act of 1934 (Amendment No.) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confiden

Registration Rights Agreement, dated June 3, 2024, by and among the Company and the Investors named therein

EX-10.2 Exhibit 10.2 REGISTRATION RIGHTS AGREEMENT THIS REGISTRATION RIGHTS AGREEMENT (this “Agreement”), dated as of June 3, 2024, is entered into by and among Summit Therapeutics Inc., a Delaware corporation (the “Company”), and the several investors signatory hereto (individually as an “Investor” and collectively together with their respective permitted assigns, the “Investors”). Capitalized te

Presented by Dr. Li Zhang, ASCO 2024

Exhibit 99.1 Presented by Dr. Li Zhang, ASCO 2024 Presented by Dr. Li Zhang, ASCO 2024 Presented by Dr. Li Zhang, ASCO 2024 Presented by Dr. Li Zhang, ASCO 2024 Presented by Dr. Li Zhang, ASCO 2024 Presented by Dr. Li Zhang, ASCO 2024 Presented by Dr. Li Zhang, ASCO 2024 Presented by Dr. Li Zhang, ASCO 2024 Presented by Dr. Li Zhang, ASCO 2024 Presented by Dr. Li Zhang, ASCO 2024 Presented by Dr.

Summit Raises $200 Million; Also Expands License Territories for Ivonescimab $200 Million in Net Proceeds Raised at Premium to Previous Closing Price In Separate Transaction, Summit Expanded License Territories for Ivonescimab in Deal with Akeso to i

Exhibit 99.1 Summit Raises $200 Million; Also Expands License Territories for Ivonescimab $200 Million in Net Proceeds Raised at Premium to Previous Closing Price In Separate Transaction, Summit Expanded License Territories for Ivonescimab in Deal with Akeso to include Latin America, Middle East, and Africa Expansion Is in Addition to Existing License Territories of US, Canada, Europe, and Japan C

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): May 31, 2024 Summit Therapeutics

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): May 31, 2024 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commission F

Securities Purchase Agreement, dated June 3, 2024, by and among the Company and the Investors named therein

EX-10.1 Exhibit 10.1 SECURITIES PURCHASE AGREEMENT This SECURITIES PURCHASE AGREEMENT (this “Agreement”) is dated as of June 3, 2024, by and among Summit Therapeutics Inc., a Delaware corporation (the “Company”), and each of the entities listed on Exhibit A attached to this Agreement (each, an “Investor” and together, the “Investors”). WHEREAS, the Company and the Investors are executing and deliv

Ivonescimab Manuscript for HARMONi-A Clinical Trial Results Published in JAMA Publication Entitled: Ivonescimab Plus Chemotherapy in Non–Small Cell Lung Cancer With EGFR Variant: A Randomized Clinical Trial HARMONi-A was Featured in Oral Presentation

EX-99.3 Exhibit 99.3 Ivonescimab Manuscript for HARMONi-A Clinical Trial Results Published in JAMA Publication Entitled: Ivonescimab Plus Chemotherapy in Non–Small Cell Lung Cancer With EGFR Variant: A Randomized Clinical Trial HARMONi-A was Featured in Oral Presentation at ASCO 2024 on May 31, 2024 Conference Call to be Held at 8:00am ET on Monday, June 3, 2024 Miami, Florida, June 1, 2024 – Summ

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of Earliest Event Reported): June 3, 2024 Summit Therapeutics

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of Earliest Event Reported): June 3, 2024 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commission F

Ivonescimab in Combination with Chemotherapy Approved in China by NMPA for 2L+ EGFRm NSCLC based on HARMONi-A Clinical Trial: Positive Trend Observed in Overall Survival towards Ivonescimab Plus Chemotherapy Separate & Distinct from HARMONi-2 Announc

EX-99.2 Exhibit 99.2 Ivonescimab in Combination with Chemotherapy Approved in China by NMPA for 2L+ EGFRm NSCLC based on HARMONi-A Clinical Trial: Positive Trend Observed in Overall Survival towards Ivonescimab Plus Chemotherapy Separate & Distinct from HARMONi-2 Announcement, HARMONi-A Showed Clinically Meaningful and Statistically Significant Benefit: PFS Hazard Ratio of 0.46 For Subset of Patie

1 Ivonescimab Monotherapy Decisively Beats Pembrolizumab Monotherapy Head-to- Head, Achieves Statistically Significant Superiority in PFS in First-Line Treatment of Patients with PD-L1 Positive NSCLC in China Unprecedented: Ivonescimab Is the First D

1 Ivonescimab Monotherapy Decisively Beats Pembrolizumab Monotherapy Head-to- Head, Achieves Statistically Significant Superiority in PFS in First-Line Treatment of Patients with PD-L1 Positive NSCLC in China Unprecedented: Ivonescimab Is the First Drug to Achieve Clinically Meaningful Benefit over Pembrolizumab in Randomized Phase III Clinical Trial in NSCLC Monotherapy Ivonescimab Achieved Clini

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): May 30, 2024

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): May 30, 2024 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commission F

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): May 24, 2024

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): May 24, 2024 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commission F

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): May 13, 2024

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): May 13, 2024 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commission F

Distribution Agreement, dated May 13, 2024, by and between Summit Therapeutics Inc. and J.P. Morgan Securities LLC

DISTRIBUTION AGREEMENT May 13, 2024 J.P. Morgan Securities LLC 383 Madison Avenue New York, New York 10179 Ladies and Gentlemen: Summit Therapeutics Inc., a Delaware corporation (the “Company”), confirms its agreement with J.P. Morgan Securities LLC, as agent and/or principal under any Terms Agreement (as defined in Section 1(a) below) (“you” or the “Agent”), with respect to the issuance and sale

Up to $90,000,000 Common Stock

Table of Contents Filed pursuant to Rule 424(b)(5) Registration No. 333-277169 PROSPECTUS SUPPLEMENT (to Prospectus dated February 27, 2024) Up to $90,000,000 Common Stock We have entered into a distribution agreement (the “Distribution Agreement”) with J.P. Morgan Securities LLC (which we refer to as the “Sales Agent”), relating to shares of our common stock, par value $0.01 per share, offered by

Lease Agreement, dated January 8, 2024 by and between Brickell Key Center, LLC and Summit Therapeutics, Inc (incorporated by reference to Exhibit 10.2 to the Company’s Quarterly Report on Form 10-Q (File No. 001-36866), filed with the Securities and Exchange Commission on May 1, 2024)

LEASE AGREEMENT by and between BRICKELL KEY CENTRE, LLC (“Landlord”) and SUMMIT THERAPEUTICS INC.

2020 Stock Incentive Plan (as amended and restated as of October 12, 2023).

Summit Therapeutics Inc. - S-8 Exhibit 99.1 Annex A SUMMIT THERAPEUTICS INC. 2020 STOCK INCENTIVE PLAN As Amended and Restated on October 12, 2023 1. Purpose The purpose of this 2020 Stock Incentive Plan (the “Plan”) of Summit Therapeutics Inc., a Delaware corporation (the “Company”), is to advance the interests of the Company’s stockholders by enhancing the Company’s ability to attract, retain an

Summit Therapeutics Q1 2024 Earnings Call May 1, 2024 9:00am ET Forward Looking Statement 2 Any statements in this presentation about the Company’s future expectations, plans and prospects, including but not limited to, statements about the clinical

a20240501q12024earningsc Summit Therapeutics Q1 2024 Earnings Call May 1, 2024 9:00am ET Forward Looking Statement 2 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.

Filing Fee Table.

EXHIBIT 107 Calculation of Filing Fee Tables S-8 (Form Type) SUMMIT THERAPEUTICS INC.

As filed with the Securities and Exchange Commission on May 1, 2024

As filed with the Securities and Exchange Commission on May 1, 2024 Registration No.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2024 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-36866 Summit Th

Summit Therapeutics Reports Financial Results and Operational Progress for the First Quarter Ended March 31, 2024 HARMONi and HARMONi-3 Enrollment Continues Promising Intracranial Anti-Tumor Activity and Safety Data Featured at the 2024 European Lung

Summit Therapeutics Reports Financial Results and Operational Progress for the First Quarter Ended March 31, 2024 HARMONi and HARMONi-3 Enrollment Continues Promising Intracranial Anti-Tumor Activity and Safety Data Featured at the 2024 European Lung Cancer Congress with Ivonescimab Alone or Combined with Chemotherapy Achieving 34% Intracranial Responses; Median Intracranial PFS of 19.

Summit Therape

Exhibit 10.1 October 31, 2023 Dr. Mahkam Zanganeh 51 Adam Way Atherton, CA 94027 Email: [email protected] Re: Offer of Employment Dear Maky: This letter, together with the appendices attached hereto, sets forth the details of your updated employment terms effective October 13, 2023, and we would ask you to read through each of the sections. An overview of the terms of your employment and compensa

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): May 1, 2024

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): May 1, 2024 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commission Fi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) Information Required in Proxy Statement Schedule 14a Information Proxy Statement Pursuant to Section 14(a) of The Securities Exchange Act of 1934 (Ame

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) Information Required in Proxy Statement Schedule 14a Information Proxy Statement Pursuant to Section 14(a) of The Securities Exchange Act of 1934 (Amendment No.) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confiden

1 Summit Therapeutics Appoints Dr. Mostafa Ronaghi, Renowned Executive and Genomicist, to its Board of Directors Miami, Florida, April 11, 2024 – Summit Therapeutics Inc. (NASDAQ: SMMT) (“Summit,” “we,” or the “Company”) today announced that Mostafa

1 Summit Therapeutics Appoints Dr. Mostafa Ronaghi, Renowned Executive and Genomicist, to its Board of Directors Miami, Florida, April 11, 2024 – Summit Therapeutics Inc. (NASDAQ: SMMT) (“Summit,” “we,” or the “Company”) today announced that Mostafa Ronaghi, PhD, has been appointed to its Board of Directors, effective immediately. “We are excited to add Dr. Ronaghi to complement our excellent grou

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

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): April 11, 2024 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commission

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): April 2, 2024

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): April 2, 2024 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commission

BACKGROUND FPN: 174P Intracranial Activity of Ivonescimab Alone or In Combination with Platinum Doublet Chemotherapy in Patients with Advanced Non-Small Cell Lung Cancer and Brain Metastases • Ivonescimab is an investigational novel bispecific antibo

BACKGROUND FPN: 174P Intracranial Activity of Ivonescimab Alone or In Combination with Platinum Doublet Chemotherapy in Patients with Advanced Non-Small Cell Lung Cancer and Brain Metastases • Ivonescimab is an investigational novel bispecific antibody against PD-1 and VEGF1 (Fig 1, Panel A) • Ivonescimab demonstrates cooperative binding, as shown in in vitro studies2: • >18x increase in PD-1 binding in presence of VEGF • >4x increase in VEGF binding in presence of PD-1 • The intracranial activity of ivonescimab remains unknown.

1 Promising Intracranial Anti-Tumor Activity and Safety Data for Ivonescimab in NSCLC Patients with Brain Metastases Featured at ELCC 2024 Ivonescimab alone or combined with chemotherapy led to intracranial responses among 34% of patients with brain

1 Promising Intracranial Anti-Tumor Activity and Safety Data for Ivonescimab in NSCLC Patients with Brain Metastases Featured at ELCC 2024 Ivonescimab alone or combined with chemotherapy led to intracranial responses among 34% of patients with brain metastases at baseline – 23% achieved a complete response All patients who did not achieve an intracranial response demonstrated stable disease or non-progression by RANO criteria irrespective of cohort Median intracranial PFS of 19.

Financial Statements and Exhibits, Other Events

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): March 22, 2024 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commission

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): March 12, 2024

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): March 12, 2024 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commission

Barclays 26th Annual Global Healthcare Conference Dr. Maky Zanganeh Bob Duggan CEO & President Chairman & CEO Forward Looking Statement Ivonescimab is an investigational therapy that is not approved by any regulatory authority. It is currently being

barclayshealthcareconfer Barclays 26th Annual Global Healthcare Conference Dr. Maky Zanganeh Bob Duggan CEO & President Chairman & CEO Forward Looking Statement Ivonescimab is an investigational therapy that is not approved by any regulatory authority. It is currently being investigated in Phase III clinical studies. 2 Summit Proprietary Information - Do Not Copy, Photograph or Distribute Barclays

1 Summit Therapeutics to Present at the Barclays 26th Annual Global Healthcare Conference Miami, Florida, March 05, 2024 – Summit Therapeutics Inc. (NASDAQ: SMMT) (“Summit,” “we,” or the “Company”) today announced that it will participate in and pres

a2024prx0305xbarclayste 1 Summit Therapeutics to Present at the Barclays 26th Annual Global Healthcare Conference Miami, Florida, March 05, 2024 – Summit Therapeutics Inc.

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): March 5, 2024

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): March 5, 2024 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commission

SUMMIT THERAPEUTICS INC. 601 Brickell Key Drive, Suite 1000 Miami, FL 33131 (650) 460-8308

SUMMIT THERAPEUTICS INC. 601 Brickell Key Drive, Suite 1000 Miami, FL 33131 (650) 460-8308 February 23, 2024 Via EDGAR Securities and Exchange Commission Division of Corporation Finance 100 F Street, N.E. Washington, D.C. 20549 Re: Summit Therapeutics Inc. Registration Statement on Form S-3 File No. 333-277169 Request for Acceleration Ladies and Gentlemen: Pursuant to Rule 461 promulgated under th

ed Compensation Clawback Policy

Exhibit 97.1 SUMMIT THERAEUTICS, INC. INCENTIVE-BASED COMPENSATION CLAWBACK POLICY Summit Therapeutics Inc. (“Company”) has adopted this clawback policy (the “Policy”) as a supplement to any other clawback policies in effect now or in the future at the Company. To the extent this Policy applies to compensation payable to a covered person, it shall be the only clawback policy applicable to such com

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2023 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 001-36866 Summit Therape

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM S-3 REGISTRATION STATEMENT THE SECURITIES ACT OF 1933 Summit Therapeutics Inc. (Exact name of registrant as specified in its charter)

As filed with the Securities and Exchange Commission on February 20, 2024 Registration No.

Form of Indenture

Summit Therapeutics Inc. S-3 Exhibit 4.1 SUMMIT THERAPEUTICS INC. INDENTURE Dated as of , 20 [], As Trustee TABLE OF CONTENTS Page ARTICLE I DEFINITIONS AND INCORPORATION BY REFERENCE 6 1.1 Definitions 6 1.2 Other Definitions 8 1.3 Incorporation by Reference of Trust Indenture Act 9 1.4 Rules of Construction 9 ARTICLE II THE SECURITIES 9 2.1 Issuable in Series 9 2.2 Establishment of Terms of Serie

Filing Fee Table

Summit Therapeutics Inc. S-3 Exhibit 107 Calculation of Filing Fee Tables Form S-3 (Form Type) Summit Therapeutics Inc. (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered Securities Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered (1) Proposed Maximum Offering Price Per Unit (2) Maximum Aggregate Offering Price (3) Fee Rate Am

Summit Therapeutics Q4 & Full Year 2023 Earnings Call February 20, 2024 9:00am ET Forward Looking Statement Ivonescimab is an investigational therapy that is not approved by any regulatory authority. It is currently being investigated in Phase III cl

a20240220q4fy23earningsc Summit Therapeutics Q4 & Full Year 2023 Earnings Call February 20, 2024 9:00am ET Forward Looking Statement Ivonescimab is an investigational therapy that is not approved by any regulatory authority.

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): February 20, 2024

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): February 20, 2024 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commiss

Summit Therapeutics Reports Financial Results and Operational Progress for the Fourth Quarter and Year Ended December 31, 2023 Actively Enrolling Two Phase III Clinical Studies in NSCLC for Ivonescimab: HARMONi and HARMONi-3 Updated Phase II Data Ann

Summit Therapeutics Reports Financial Results and Operational Progress for the Fourth Quarter and Year Ended December 31, 2023 Actively Enrolling Two Phase III Clinical Studies in NSCLC for Ivonescimab: HARMONi and HARMONi-3 Updated Phase II Data Announced for Ivonescimab Highlighting 24-Month OS Rate of 64.

List of Significant Subsidiaries

Exhibit 21.1 SUBSIDIARIES OF THE REGISTRANT Name of Subsidiary Jurisdiction of incorporation or organization Summit (Oxford) Limited England and Wales Discuva Limited England and Wales Summit Therapeutics Sub Inc. Delaware, USA Summit Therapeutics Limited England and Wales Summit International Holdings Limited Cayman Islands Summit Therapeutics Global LLC Delaware, USA

Amended and Restated Promissory Note, dated February 17, 2024, by and

Exhibit 10.51 THIS NOTE HAS NOT BEEN REGISTERED UNDER THE UNITED STATES SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), OR ANY STATE SECURITIES LAWS AND MAY NOT BE OFFERED, SOLD, PLEDGED, ASSIGNED, OR OTHERWISE TRANSFERRED UNLESS (1) A REGISTRATION STATEMENT WITH RESPECT HERETO IS EFFECTIVE UNDER THE SECURITIES ACT AND ANY APPLICABLE STATE SECURITIES LAWS OR (2) THE COMPANY RECEIVES AN

Oppenheimer’s 34th Annual Healthcare Life Sciences Conference Dr. Maky Zanganeh Bob Duggan CEO & President Chairman & CEO Forward Looking Statement Ivonescimab is an investigational therapy that is not approved by any regulatory authority. It is curr

a20240201opcohcconfinves Oppenheimer’s 34th Annual Healthcare Life Sciences Conference Dr.

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): February 14, 2024

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): February 14, 2024 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commiss

1 Summit Therapeutics to Present at Oppenheimer’s 34th Annual Healthcare Life Sciences Conference Miami, Florida, February 07, 2024 – Summit Therapeutics Inc. (NASDAQ: SMMT) (“Summit,” “we,” or the “Company”) today announced that it will participate

a2024prx0207xopco-annou 1 Summit Therapeutics to Present at Oppenheimer’s 34th Annual Healthcare Life Sciences Conference Miami, Florida, February 07, 2024 – Summit Therapeutics Inc.

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): February 7, 2024

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): February 7, 2024 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commissi

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): January 8, 2024

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): January 8, 2024 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commissio

42nd Annual J.P. Morgan Healthcare Conference Bob Duggan Dr. Maky Zanganeh Chairman & CEO CEO & President Forward Looking Statement Ivonescimab is an investigational therapy that is not approved by any regulatory authority. It is currently being inve

jpm2024deck1208231-8x24 42nd Annual J.P. Morgan Healthcare Conference Bob Duggan Dr. Maky Zanganeh Chairman & CEO CEO & President Forward Looking Statement Ivonescimab is an investigational therapy that is not approved by any regulatory authority. It is currently being investigated in Phase III clinical studies. 2 Summit Proprietary Information - Do Not Copy, Photograph or Distribute J.P. Morgan 4

1 Summit Therapeutics Announces Updated Phase II Data for Ivonescimab at 42nd Annual J.P. Morgan Healthcare Conference Phase II 24-Month OS Rate of 64.8% in 1L Squamous NSCLC Patients Phase II mOS of 22.5 Months in 2L+ EGFRm, TKI-progressed NSCLC Pat

a2024prx0108xjpmpresent 1 Summit Therapeutics Announces Updated Phase II Data for Ivonescimab at 42nd Annual J.

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): January 3, 2024

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): January 3, 2024 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commissio

1 Summit Therapeutics to Present at the 42nd Annual J.P. Morgan Healthcare Conference Menlo Park, California, January 3, 2024 – Summit Therapeutics Inc. (NASDAQ: SMMT) (“Summit,” “we,” or the “Company”) today announced that it will participate in and

a2024prx0103xjpmannounc 1 Summit Therapeutics to Present at the 42nd Annual J.P. Morgan Healthcare Conference Menlo Park, California, January 3, 2024 – Summit Therapeutics Inc. (NASDAQ: SMMT) (“Summit,” “we,” or the “Company”) today announced that it will participate in and present at the 42nd Annual J.P. Morgan Healthcare Conference on Tuesday, January 09, 2023, at 1:30 PM PT. Robert W. Duggan, C

Employment Agreement, dated October 13, 2023, by and between Summit Therapeutics

Exhibit 10.1 EMPLOYMENT AGREEMENT by and between Summit Therapeutics, Inc. and Manmeet S. Soni THIS EMPLOYMENT AGREEMENT (the “Agreement”) is made and entered into as of October 13, 2023, by and between Summit Therapeutics, Inc., a Delaware corporation (together with its successors and assigns permitted hereunder, the “Company”), and Manmeet S. Soni (the “Executive”). 1.Position: As of October 13,

Securities Purchase Agreement, dated October 13, 2023, by and between Summit Therapeutics Inc. and Manmeet Son

EXHIBIT 10.2 SECURITIES PURCHASE AGREEMENT This SECURITIES PURCHASE AGREEMENT (this “Agreement”) is made and entered into as of October 13, 2023 by and among Summit Therapeutics Inc., a Delaware corporation, with its principal place of business at 2882 Sand Hill Road, Suite 106, Menlo Park, CA (the “Company”), and the investor named on the signature page hereto (the “Investor”). RECITALS A.The Com

Financial Statements and Exhibits, Results of Operations and Financial Condition

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, 2023 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commissi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2023 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-36866 Summi

Summit Therapeutics Reports Financial Results and Operational Progress for the Third Quarter and Nine Months Ended September 30, 2023 Enrollment Initiated in Second Phase III Clinical Study for Ivonescimab, HARMONi-3 Continuing Enrollment of HARMONi

Summit Therapeutics Reports Financial Results and Operational Progress for the Third Quarter and Nine Months Ended September 30, 2023 Enrollment Initiated in Second Phase III Clinical Study for Ivonescimab, HARMONi-3 Continuing Enrollment of HARMONi Phase III Study, with Enrollment Completion Expected in Second Half of 2024 Manmeet S.

1 Ivonescimab’s Novel Mechanism of Action Highlighting Cooperative Binding to be Featured in Poster Presentation at SITC 2023 Potential First-in-Class Tetravalent Bispecific Antibody Demonstrates Enhanced Binding in the Simultaneous Presence of PD-1

a2023prx1031xsitcposter 1 Ivonescimab’s Novel Mechanism of Action Highlighting Cooperative Binding to be Featured in Poster Presentation at SITC 2023 Potential First-in-Class Tetravalent Bispecific Antibody Demonstrates Enhanced Binding in the Simultaneous Presence of PD-1 & VEGF Cooperative Binding of SMT112 Enables Higher Avidity in the Tumor Microenvironment with Over 18 Fold Increased Binding Affinity to PD-1 in the Presence of VEGF in vitro Menlo Park, California, October 31, 2023 – Summit Therapeutics Inc.

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): October 31, 2023

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): October 31, 2023 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commissi

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): October 12, 2023

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): October 12, 2023 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commissi

1 Summit Therapeutics Appoints Proven Biotech Leader Manmeet S. Soni as Chief Operating Officer Mr. Soni Invests $5 Million in Summit while Joining Executive Team In Corresponding Appointments, Dave Gancarz, Urte Gayko, PhD, Fong Clow, DSc, & Allen S

a2023prx1016xmanmeetdav 1 Summit Therapeutics Appoints Proven Biotech Leader Manmeet S.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.     )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.     ) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.     )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.     ) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☒ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-

Summit Therapeutics Reports Financial Results and Operational Progress for the Second Quarter and Six Months Ended June 30, 2023 Promising Updated Phase II Data Presented at ASCO 2023 for Ivonescimab First US Patient Treated in Ivonescimab Phase III

Summit Therapeutics Reports Financial Results and Operational Progress for the Second Quarter and Six Months Ended June 30, 2023 Promising Updated Phase II Data Presented at ASCO 2023 for Ivonescimab First US Patient Treated in Ivonescimab Phase III Clinical Trial with the First Patient in Ivonescimab's Second Phase III Clinical Trial Planned for the Second Half of 2023 Menlo Park, California, August 9, 2023 - Summit Therapeutics Inc.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2023 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-36866 Summit The

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 9, 2023

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 9, 2023 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commission

1 Summit Therapeutics to Host Q2 2023 Financial Results & Operational Progress Call on August 9, 2023 Conference Call to be Held at 9:00am ET Menlo Park, California, August 2, 2023 - Summit Therapeutics Inc. (NASDAQ: SMMT) (“Summit,” “we,” or the “Co

a2023prx0802xannounceme 1 Summit Therapeutics to Host Q2 2023 Financial Results & Operational Progress Call on August 9, 2023 Conference Call to be Held at 9:00am ET Menlo Park, California, August 2, 2023 - Summit Therapeutics Inc.

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 2, 2023

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 2, 2023 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commission

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of Earliest Event Reported): June 4, 2023

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of Earliest Event Reported): June 4, 2023 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commission F

1 Promising Data for Investigational Innovative Bispecific Ivonescimab Featured at ASCO 2023 Data Supporting Summit’s Planned Phase III Trial for First-line Metastatic Squamous NSCLC Patients on Display Phase II ORR of 67% with a mDOR of 15 months in

EX-99.1 2 a2023prx0604xasco-poste.htm EX-99.1 1 Promising Data for Investigational Innovative Bispecific Ivonescimab Featured at ASCO 2023 Data Supporting Summit’s Planned Phase III Trial for First-line Metastatic Squamous NSCLC Patients on Display Phase II ORR of 67% with a mDOR of 15 months in 1L SQ-NSCLC Patients Menlo Park, California, June 4, 2023 - Summit Therapeutics Inc. (NASDAQ: SMMT) (“S

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of Earliest Event Reported): June 1, 2023 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commission F

1 Ivonescimab Updated Data to be Featured at ASCO 2023 Summit Therapeutics is Currently Enrolling in a Phase III Study with Additional Phase III Study Planned for Third Quarter 2023 for Ivonescimab Menlo Park, California, June 1, 2023 - Summit Therap

a2023prx0601xascoposter 1 Ivonescimab Updated Data to be Featured at ASCO 2023 Summit Therapeutics is Currently Enrolling in a Phase III Study with Additional Phase III Study Planned for Third Quarter 2023 for Ivonescimab Menlo Park, California, June 1, 2023 - Summit Therapeutics Inc.

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): May 23, 2023

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): May 23, 2023 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commission F

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): May 11, 2023

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): May 11, 2023 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commission F

Summit Therapeutics Reports Financial Results and Operational Progress for the First Quarter Ended March 31, 2023 First US Patient Treated in Ivonescimab Clinical Trial after Closing Agreement; $500M Raised in Fully-Subscribed Rights Offering

Summit Therapeutics Reports Financial Results and Operational Progress for the First Quarter Ended March 31, 2023 First US Patient Treated in Ivonescimab Clinical Trial after Closing Agreement; $500M Raised in Fully-Subscribed Rights Offering Menlo Park, California, May 11, 2023 - Summit Therapeutics Inc.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2023 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-36866 Summit Th

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): May 9, 2023

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): May 9, 2023 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commission Fi

1 Summit Therapeutics Announces First Patient Treated in Phase III HARMONi Clinical Trial Evaluating Ivonescimab (SMT112) Phase III Study Designed to Establish the Effect of Ivonescimab in Lung Cancer Patients Whose Tumors Progressed after EGFR-TKI T

a2023prx0509xfirst-pati 1 Summit Therapeutics Announces First Patient Treated in Phase III HARMONi Clinical Trial Evaluating Ivonescimab (SMT112) Phase III Study Designed to Establish the Effect of Ivonescimab in Lung Cancer Patients Whose Tumors Progressed after EGFR-TKI Therapy Menlo Park, California, May 9, 2023 - Summit Therapeutics Inc.

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): May 3, 2023

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): May 3, 2023 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commission Fi

1 Summit Therapeutics Announces Initial Indications for Clinical Trials for Ivonescimab (SMT112) Studies Designed in Alignment with Feedback from FDA Company to Host Q1 Earnings Call on May 11, 2023 at 9:00am ET Menlo Park, California, May 3, 2023 -

1 Summit Therapeutics Announces Initial Indications for Clinical Trials for Ivonescimab (SMT112) Studies Designed in Alignment with Feedback from FDA Company to Host Q1 Earnings Call on May 11, 2023 at 9:00am ET Menlo Park, California, May 3, 2023 - Summit Therapeutics Inc.

SUMMIT THERAPEUTICS INC. 2882 Sand Hill Road, Suite 106 Menlo Park, CA 94025 (650) 460-8308

SUMMIT THERAPEUTICS INC. 2882 Sand Hill Road, Suite 106 Menlo Park, CA 94025 (650) 460-8308 April 25, 2023 Via EDGAR Securities and Exchange Commission Division of Corporation Finance 100 F Street, N.E. Washington, D.C. 20549 Re: Summit Therapeutics Inc. Registration Statement on Form S-3 File No. 333-270656 Request for Acceleration Ladies and Gentlemen: Pursuant to Rule 461 promulgated under the

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) Information Required in Proxy Statement Schedule 14a Information Proxy Statement Pursuant to Section 14(a) of The Securities Exchange Act of 1934 (Ame

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) Information Required in Proxy Statement Schedule 14a Information Proxy Statement Pursuant to Section 14(a) of The Securities Exchange Act of 1934 (Amendment No.) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confiden

Filing fee table

Summit Therapeutics Inc. S-3 Exhibit 107 Calculation of Filing Fee Tables S-3 (Form Type) Summit Therapeutics Inc. (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered Securities Security Type Security Class Title (1) Fee Calculation Rate Amount Registered Proposed Maximum Offering Price Per Security (2) Maximum Aggregate Offering Price(2) Fee Rate Amount of Registratio

As filed with the U.S. Securities and Exchange Commission on March 17, 2023

As filed with the U.S. Securities and Exchange Commission on March 17, 2023 Registration Statement No. 333- UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM S-3 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 Summit Therapeutics Inc. (Exact name of registrant as specified in its charter) Delaware 37-1979717 (State or other jurisdiction of incorporation or organi

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): March 17, 2023

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): March 17, 2023 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commission

GB:SUMM / SUMMIT THERAPEUTICS PLC / Zanganeh Maky - AMENDMENT TO FORM SC 13D Activist Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D (Rule 13d-101) INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO § 240.13d-1(a) AND AMENDMENTS THERETO FILED PURSUANT TO § 240.13d-2(a) (Amendment No. 3)1 Summit Therapeutics Inc. (Name of Issuer) Common Stock, par value $0.01 per share (Title of Class of Securities) 86627T108 (CUSIP Number) ADAM W. FINER

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2022 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 001-36866 Summit Therape

Amended and Restated 2020 Stock Incentive Plan, dated July 27, 2022

amendedandrestated2020st SUMMIT THERAPEUTICS INC. 2020 STOCK INCENTIVE PLAN As Amended and Restated on July 27, 2022 1. Purpose The purpose of this 2020 Stock Incentive Plan (the “Plan”) of Summit Therapeutics Inc., a Delaware corporation (the “Company”), is to advance the interests of the Company’s stockholders by enhancing the Company’s ability to attract, retain and motivate persons who are exp

Summit Therapeutics Reports Financial Results and Operational Progress for the Fourth Quarter and Year Ended December 31, 2022 Earnings Call with Management Team Scheduled for Today at 9:00am EST Menlo Park, California, March 9, 2023 - Summit Therape

a2023prx0309xq4-2022xfi Summit Therapeutics Reports Financial Results and Operational Progress for the Fourth Quarter and Year Ended December 31, 2022 Earnings Call with Management Team Scheduled for Today at 9:00am EST Menlo Park, California, March 9, 2023 - Summit Therapeutics Inc.

, 2022, by and between Summit Therapeutics Inc. and Ankur Dhingra

executedofferdocuments-a 15 April 2022 Ankur Dhingra Email: [**] Re: Offer of Employment Dear Ankur, We are delighted to offer you the position of CFO at Summit Therapeutics, Inc.

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): March 9, 2023

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): March 9, 2023 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commission

Second Amendment to Sublease Agreement, dated July 29, 2022, by and among Summit Therapeutics Inc. and Maky Zanganeh and Associates, Inc.

amd2tosublease SECOND AMENDMENT TO SUBLEASE ThisSECONDAMENDMENTTOSUBLEASE(this"Second Amendment") has an Effective Date of the 1st day of August, 2022, by and between MAKY ZANGANEH & ASSIOCIATES INC.

First Amendment to Sublease Agreement, dated July 25, 2022, by and among Summit Therapeutics Inc. and Maky Zanganeh and Associates, Inc.

amd1tosublease 1 FIRST AMENDMENT SUBLEASE This FIRST AMENDMENT TO SUBLEASE (this "First Amendment") is made and entered into as of the 19th day of July, 2022, by and between MAKY ZANGANEH & ASSIOCIATES INC.

List of Significant Subsidiaries

Exhibit 21.1 SUBSIDIARIES OF THE REGISTRANT Name of Subsidiary Jurisdiction of incorporation or organization Summit (Oxford) Limited England and Wales Discuva Limited England and Wales Summit Therapeutics Sub Inc. Delaware, USA Summit Therapeutics Limited England and Wales Summit Corporation Limited England and Wales Summit (Wales) Limited England and Wales Summit (Cambridge) Limited England and W

Financial Statements and Exhibits, Other Events

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): March 1, 2023 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commission

Summit Therapeutics Closes Fully-Subscribed $500 Million Rights Offering Successful capital raise provides a present-time cash runway into the second half of 2024 Company to host Q4 Earnings Call on March 9, 2023 at 9:00am ET

EX-99.1 2 a2023prx0223xrightsofferi.htm EX-99.1 Summit Therapeutics Closes Fully-Subscribed $500 Million Rights Offering Successful capital raise provides a present-time cash runway into the second half of 2024 Company to host Q4 Earnings Call on March 9, 2023 at 9:00am ET Menlo Park, California, March 3, 2023 - Summit Therapeutics Inc. (NASDAQ: SMMT) (“Summit,” “we,” or the “Company”) today annou

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): February 23, 2023

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): February 23, 2023 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commiss

Summit Therapeutics’ Rights Offering Nearing Expiration Date Rights Offering Seeks to Raise up to $500 Million

Summit Therapeutics’ Rights Offering Nearing Expiration Date Rights Offering Seeks to Raise up to $500 Million Menlo Park, California, February 23, 2023 - Summit Therapeutics Inc.

GB:SUMM / SUMMIT THERAPEUTICS PLC / DUGGAN ROBERT W - SC 13D/A Activist Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D (Rule 13d-101) INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO § 240.13d-1(a) AND AMENDMENTS THERETO FILED PURSUANT TO § 240.13d-2(a) (Amendment No. 8)1 Summit Therapeutics Inc. (Name of Issuer) Common Stock, par value $0.01 per share (Title of Class of Securities) 86627T108 (CUSIP Number) ADAM W. FINER

GB:SUMM / SUMMIT THERAPEUTICS PLC / Polar Capital Holdings Plc Passive Investment

SC 13G/A 1 polar-smmt123122a2.htm UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 13G/A Under the Securities Exchange Act of 1934 (Amendment No. 2)* Summit Therapeutics Inc. (Name of Issuer) Common Stock, $0.01 par value per share (Title of Class of Securities) 86627T108 (CUSIP Number) December 31, 2022 (Date of Event Which Requires Filing of this Statement) Check th

SUMMIT THERAPEUTICS INC. Subscription Rights to Purchase Up to 476,190,476 Shares of Common Stock at the Initial Price

Filed Pursuant to Rule 424(b)(4) Registration No. 333-268932 PROSPECTUS SUMMIT THERAPEUTICS INC. Subscription Rights to Purchase Up to 476,190,476 Shares of Common Stock at the Initial Price Summit Therapeutics Inc. is distributing at no charge to the holders of our common stock, par value $0.01 per share, non-transferable subscription rights (each, a “Subscription Right”) to purchase up to 476,19

SUMMIT THERAPEUTICS INC. 2882 Sand Hill Road, Suite 106 Menlo Park, CA 94025

SUMMIT THERAPEUTICS INC. 2882 Sand Hill Road, Suite 106 Menlo Park, CA 94025 (44)-0-1235-443-939 January 31, 2023 Via EDGAR Securities and Exchange Commission Division of Corporation Finance 100 F Street, N.E. Washington, D.C. 20549 Re: Summit Therapeutics Inc. Registration Statement on Form S-3 File No. 333-268932 Request for Acceleration Ladies and Gentlemen: Pursuant to Rule 461 promulgated und

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): January 30, 2023

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): January 30, 2023 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commissi

1 Summit Therapeutics Announces Timing of Rights Offering for Up to $500 Million Menlo Park, California, January 30, 2023 - Summit Therapeutics Inc. (NASDAQ: SMMT) (“Summit” or the “Company”) today announced that the Company’s Board of Directors has

a2023prx0130xannounceme 1 Summit Therapeutics Announces Timing of Rights Offering for Up to $500 Million Menlo Park, California, January 30, 2023 - Summit Therapeutics Inc.

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): January 27, 2023

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): January 27, 2023 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commissi

As filed with the U.S. Securities and Exchange Commission on January 20, 2023.

As filed with the U.S. Securities and Exchange Commission on January 20, 2023. Registration Statement No. 333-268932 UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM S-3/A (AMENDMENT NO. 1) REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 Summit Therapeutics Inc. (Exact name of registrant as specified in its charter) Delaware 37-1979717 (State or other jurisdicti

Amendment No. 1 to Collaboration and License Agreement Amendment, dated January 16, 2023, by and among Summit Therapeutics Inc. and Akeso, Inc. (incorporated by reference to Exhibit 10.1 of Form 8-K filed by the Company on January 20, 2023, File No. 001-36866)

AMENDMENT No. 1 to Collaboration and License Agreement between Akeso, Inc. and Summit Therapeutics Sub, Inc. This Amendment No. 1 (“Amendment No. 1” or “Amendment”) is entered into as of January 16, 2023 (“Amendment No. 1 Effective Date”) by and between Akeso, Inc. (康方生物科技（开曼）有 限公司 (“Akeso") and Summit Therapeutics Sub, Inc. (“Summit”). Akeso and Summit are each referred to individually herein as

Promissory Notes, dated January 19, 2023, by and among Summit Therapeutics Inc. and Robert W. Duggan (incorporated by reference to Exhibit 10.3 of Form 8-K filed by the Company on January 20, 2023, File No. 001-36866)

EX-10.3 5 exhibit103promissorynote.htm EX-10.3 4868-3886-4459.2 EXHIBIT B-1 THIS NOTE HAS NOT BEEN REGISTERED UNDER THE UNITED STATES SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), OR ANY STATE SECURITIES LAWS AND MAY NOT BE OFFERED, SOLD, PLEDGED, ASSIGNED, OR OTHERWISE TRANSFERRED UNLESS (1) A REGISTRATION STATEMENT WITH RESPECT HERETO IS EFFECTIVE UNDER THE SECURITIES ACT AND ANY AP

1 Summit Therapeutics Closes Deal with Akeso Inc. to In-License Breakthrough Innovative Bispecific Antibody Menlo Park, California, January 20, 2023 – Summit Therapeutics Inc. (NASDAQ: SMMT) (“Summit,” “we,” or the “Company”) today announced that we

1 Summit Therapeutics Closes Deal with Akeso Inc. to In-License Breakthrough Innovative Bispecific Antibody Menlo Park, California, January 20, 2023 – Summit Therapeutics Inc. (NASDAQ: SMMT) (“Summit,” “we,” or the “Company”) today announced that we have completed the closing of our previously announced definitive agreement with Akeso Inc. (HKEX Code: 9926.HK, “Akeso”) to in-license its breakthrou

Baker&Hostetler LLP

Baker&Hostetler LLP 45 Rockefeller Plaza New York, NY 1011 January 20, 2023 T 212.

Common Stock Issuance Agreement, dated January 17, 2023, by and among Summit Therapeutics Inc. and Akeso, Inc. (incorporated by reference to Exhibit 10.2 of Form 8-K filed by the Company on January 20, 2023, File No. 001-36866)

EXECUTION Certain identified information has been excluded from the exhibit because it is both (i) not material and (ii) is the type of information that the registrant treats as private or confidential.

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year, Entry into a Material Definitive Agreement, Financial Statements and Exhibits, Other Events

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): January 16, 2023 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commissi

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): January 6, 2023

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): January 6, 2023 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commissio

J.P. Morgan 41st Annual Healthcare Conference 2023 Bob Duggan Dr. Maky Zanganeh Chairman & CEO Co-CEO, President & Board Member 2 Disclaimer and Forward-Looking Statement Any statements in this presentation about the Company’s future expectations, pl

EX-99.1 2 summitjpm4xpdfxfinalx01.htm EX-99.1 J.P. Morgan 41st Annual Healthcare Conference 2023 Bob Duggan Dr. Maky Zanganeh Chairman & CEO Co-CEO, President & Board Member 2 Disclaimer and 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 developme

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): December 22, 2022

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): December 22, 2022 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commiss

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): December 21, 2022

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): December 21, 2022 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commiss

Form of Beneficial Owner Election Form

SUMMIT THERAPEUTICS INC. FORM S-3 EX-99.6 THE TERMS AND CONDITIONS OF THE RIGHTS OFFERING ARE SET FORTH IN THE COMPANY'S PROSPECTUS DATED [] (THE “PROSPECTUS”) AND ARE INCORPORATED HEREIN BY REFERENCE. COPIES OF THE PROSPECTUS ARE AVAILABLE UPON REQUEST FROM BROADRIDGE CORPORATE ISSUER SOLUTIONS, INC., THE SUBSCRIPTION AGENT, BY CALLING (855) 793-5068. SUMMIT THERAPEUTICS INC. BENEFICIAL OWNER ELE

Form of Nominee Holder Certification

SUMMIT THERAPEUTICS INC. FORM S-3 EX-99.5 THE TERMS AND CONDITIONS OF THE RIGHTS OFFERING ARE SET FORTH IN THE COMPANY’S PROSPECTUS DATED [] (THE “PROSPECTUS”) AND ARE INCORPORATED HEREIN BY REFERENCE. COPIES OF THE PROSPECTUS ARE AVAILABLE UPON REQUEST FROM BROADRIDGE CORPORATE ISSUER SOLUTIONS INC., THE SUBSCRIPTION AGENT, BY CALLING (855) 793-5068. SUMMIT THERAPEUTICS INC. SHARES OF COMMON STOC

Form of Subscription Rights Certificate

SUMMIT THERAPEUTICS INC. FORM S-3 EX-4.1 THE TERMS AND CONDITIONS OF THE RIGHTS OFFERING ARE SET FORTH IN THE COMPANY’S PROSPECTUS DATED [], (THE “PROSPECTUS”) AND ARE INCORPORATED HEREIN BY REFERENCE. COPIES OF THE PROSPECTUS ARE AVAILABLE UPON REQUEST FROM BROADRIDGE CORPORATE ISSUER SOLUTIONS, INC., THE SUBSCRIPTION AGENT, BY CALLING (855) 793-5068. SUMMIT THERAPEUTICS INC. Incorporated under t

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K/A Amendment No. 1

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K/A Amendment No. 1 (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2021 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 001-36

Collaboration and License Agreement dated December 5, 2022 by and between Akeso, Inc. and its affiliates and Summit Therapeutics Sub, Inc.

SUMMIT THERAPEUTICS INC. FORM S-3 EX-10.1

Filing fee table

Exhibit 107 Calculation of Filing Fee Tables S-3 (Form Type) Summit Therapeutics Inc.

Form of Letter to Brokers and other Nominee Holders

SUMMIT THERAPEUTICS INC. FORM S-3 EX-99.3 FORM OF LETTER TO BROKERS AND OTHER NOMINEE HOLDERS SUMMIT THERAPEUTICS INC. Subscription Rights to Purchase Shares of Common Stock Offered Pursuant to Subscription Rights Distributed to Stockholders of Summit Therapeutics Inc. [DATE] To Securities Dealers, Commercial Banks, Trust Companies and Other Nominees: This letter is being distributed to securities

Form of Letter to Clients of Brokers and other Nominee Holders

SUMMIT THERAPEUTICS INC. FORM S-3 EX-99.4 FORM OF LETTER TO CLIENTS OF BROKERS AND OTHER NOMINEE HOLDERS SUMMIT THERAPEUTICS INC. Subscription Rights to Purchase Shares of Common Stock Offered Pursuant to Subscription Rights Distributed to Stockholders of Summit Therapeutics Inc. [DATE] To Our Clients: Enclosed for your consideration are a prospectus dated [] (the “Prospectus), and the “Instructio

Form of Letter to Stockholders who are Record Holders

SUMMIT THERAPEUTICS INC. FORM S-3 EX-99.2 FORM OF LETTER TO STOCKHOLDERS WHO ARE RECORD HOLDERS SUMMIT THERAPEUTICS INC. Shares of Common Stock Offered Pursuant to Subscription Rights Distributed to Stockholders of Summit Therapeutics Inc. [DATE] Dear Stockholder: Enclosed are materials relating to a rights offering by Summit Therapeutics Inc., a Delaware corporation (“we,” “us,” “our,” or the “Co

As filed with the U.S. Securities and Exchange Commission on December 21, 2022.

As filed with the U.S. Securities and Exchange Commission on December 21, 2022. Registration Statement No. 333- UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM S-3 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 Summit Therapeutics Inc. (Exact name of registrant as specified in its charter) Delaware 37-1979717 (State or other jurisdiction of incorporation or or

Form of Instructions As To Use of Non-Transferable Subscription Rights Certificates

SUMMIT THERAPEUTICS INC. FORM S-3 EX-99.1 THE TERMS AND CONDITIONS OF THE RIGHTS OFFERING ARE SET FORTH IN THE COMPANY’S PROSPECTUS DATED [ ] (THE “PROSPECTUS”) AND ARE INCORPORATED HEREIN BY REFERENCE. COPIES OF THE PROSPECTUS ARE AVAILABLE UPON REQUEST FROM BROADRIDGE CORPORATE ISSUER SOLUTIONS, INC., THE SUBSCRIPTION AGENT, BY CALLING (855) 793-5068. FORM OF INSTRUCTIONS AS TO USE OF SUMMIT THE

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.     )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.     ) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-

GB:SUMM / SUMMIT THERAPEUTICS PLC / DUGGAN ROBERT W - AMENDMENT TO FORM SC 13D Activist Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D (Rule 13d-101) INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO ? 240.13d-1(a) AND AMENDMENTS THERETO FILED PURSUANT TO ? 240.13d-2(a) (Amendment No. 7)1 Summit Therapeutics Inc. (Name of Issuer) Common Stock, par value $0.01 per share (Title of Class of Securities) 86627T108 (CUSIP Number) ADAM W. FINER

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): December 5, 2022

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): December 5, 2022 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commissi

Note Purchase Agreement, dated December 6, 2022, by and among Summit Therapeutics Inc., Robert W. Duggan, and Dr. Mahkam Zanganeh (incorporated by reference to Exhibit 10.1 to the Company’s Current Report on Form 8-K (File No. 001-36866), filed with the Securities and Exchange Commission on December 6, 2022)

notepurchaseagreementpre 4891-4787-1298.2 NOTE PURCHASE AGREEMENT This NOTE PURCHASE AGREEMENT (this “Agreement”) is made and entered into as of December 6, 2022 by and among Summit Therapeutics Inc., a Delaware corporation, with its principal place of business at 2882 Sand Hill Road, Suite 106, Menlo Park, CA 94025 (the “Company”), and each investor named on Exhibit A hereto (each, an “Investor”

Summit Therapeutics Partners with Akeso Inc. in Deal for Up to $5 Billion to In-License Breakthrough Innovative Bispecific Antibody $500 Million Upfront Payment to Activate the Partnership for Ivonescimab

Summit Therapeutics Partners with Akeso Inc. in Deal for Up to $5 Billion to In-License Breakthrough Innovative Bispecific Antibody $500 Million Upfront Payment to Activate the Partnership for Ivonescimab Menlo Park, California, US, and Grand Cayman, Cayman Islands, December 06, 2022 – Summit Therapeutics Inc. (NASDAQ: SMMT) (“Summit,” “we,” or the “Company”) today announced a definitive agreement

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.     )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.     ) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☒ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

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 15, 2022 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commiss

Summit Therapeutics Appoints Experienced Clinical Leader Dr. Alessandra Cesano to its Board of Directors

Summit Therapeutics Appoints Experienced Clinical Leader Dr. Alessandra Cesano to its Board of Directors Menlo Park, California ? Summit Therapeutics Inc. (NASDAQ: SMMT) (?Summit,? ?we,? or the ?Company?) today announced that Dr. Alessandra Cesano, MD, PhD, has been appointed to its Board of Directors, effective immediately. ?Dr. Cesano compliments our Board of Directors with her decades of extens

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 9, 2022

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 9, 2022 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commissi

Summit Therapeutics Inc. Reports Financial Results and Operational Progress for the Third Quarter and Nine Months Ended September 30, 2022

Summit Therapeutics Inc. Reports Financial Results and Operational Progress for the Third Quarter and Nine Months Ended September 30, 2022 Menlo Park, California, November 9, 2022 - Summit Therapeutics Inc. (NASDAQ: SMMT) ("Summit," "we," or the "Company") today reports its financial results and provides an update on operational progress for the third quarter and nine months ended September 30, 20

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2022 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-36866 Summi

Summit Therapeutics Presents Ri-CoDIFy Trial Results for Microbiome-Sparing Ridinilazole at IDWeek 2022 -Ridinilazole resulted in a 53% relative risk reduction in recurrence of C difficile infection compared to treatment with vancomycin -Ridinilazole

Summit Therapeutics Presents Ri-CoDIFy Trial Results for Microbiome-Sparing Ridinilazole at IDWeek 2022 -Ridinilazole resulted in a 53% relative risk reduction in recurrence of C difficile infection compared to treatment with vancomycin -Ridinilazole preserved the gut microbiome compared to vancomycin: both in composition and diversity of the microbiome community -Ri-CoDIFy represents the largest and most comprehensive CDI assessment of the gut microbiome to date from over 600 CDI patients -Ridinilazole?s features are consistent with the principles of good antibiotic stewardship Menlo Park, California, October 20, 2022 ? Summit Therapeutics Inc.

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): October 20, 2022

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): October 20, 2022 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commissi

Financial Statements and Exhibits, Other Events

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): September 28, 2022 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commis

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

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): September 28, 2022 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commis

Summit Therapeutics Appoints Dr. Robert Booth, Renowned Executive and Scientific Leader, to its Board of Directors

Summit Therapeutics Appoints Dr. Robert Booth, Renowned Executive and Scientific Leader, to its Board of Directors Menlo Park, California ? Summit Therapeutics Inc. (NASDAQ: SMMT) (?Summit,? ?we,? or the ?Company?) today announced that Dr. Robert Booth, PhD, has been appointed to its Board of Directors, effective immediately. Dr. Booth initiated the BTK inhibitor program at Celera Genomics, Inc. t

GB:SUMM / SUMMIT THERAPEUTICS PLC / DUGGAN ROBERT W - AMENDMENT TO FORM SC 13D Activist Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D (Rule 13d-101) INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO § 240.13d-1(a) AND AMENDMENTS THERETO FILED PURSUANT TO § 240.13d-2(a) (Amendment No. 6)1 Summit Therapeutics Inc. (Name of Issuer) Common Stock, par value $0.01 per share (Title of Class of Securities) 86627T108 (CUSIP Number) ADAM W. FINER

Financial Statements and Exhibits, Other Events

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 15, 2022 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commissio

Summit Therapeutics Inc Reports Financial Results and Operational Progress for the Second Quarter Ended June 30, 2022

Summit Therapeutics Inc Reports Financial Results and Operational Progress for the Second Quarter Ended June 30, 2022 Menlo Park, California, August 11, 2022 - Summit Therapeutics Inc.

Financial Statements and Exhibits, Results of Operations and Financial Condition

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 11, 2022 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commissio

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ? QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2022 or ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-36866 Summit The

Summit Therapeutics Closes Fully-Subscribed $100 Million Rights Offering

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Financial Statements and Exhibits, Other Events

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 9, 2022 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commission

Financial Statements and Exhibits, Results of Operations and Financial Condition

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 2, 2022 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commission

Summit Therapeutics’ Rights Offering Nearing Expiration Date Summit Provides Preliminary Update on Financial Position

Summit Therapeutics’ Rights Offering Nearing Expiration Date Summit Provides Preliminary Update on Financial Position Menlo Park, CA, August 2, 2022 - Summit Therapeutics Inc.

Financial Statements and Exhibits, Other Events, Submission of Matters to a Vote of Security Holders

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): July 27, 2022 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commission

Amendment to Restated Certificate of Incorporation of Summit Therapeutics Inc., as filed with the Delaware Secretary of State on July 27, 2022 (incorporated by reference to Exhibit 3.1 of Form 8-K filed by the Company on July 29, 2022, File No. 001-36866)

Delaware - The First State I, JEFFREY W. BULLOCK, SECRETARY OF STATE OF THE STATE OF DELAWARE, DO HEREBY CERTIFY THE ATTACHED IS A TRUE AND CORRECT COPY OF THE CERTIFICATE OF AMENDMENT OF ?SUMMIT THERAPEUTICS INC.?, FILED IN THIS OFFICE ON THE TWENTY-SEVENTH DAY OF JULY, A.D. 2022, AT 1:54 O CLOCK P.M. Jeffrey W. Bullock, Secretary of State 3262870 8100 SR# 20223102451 You may verify this certific

Summit Therapeutics Appoints Dr. Maky Zanganeh as Co-CEO & President Bob Duggan Remains Chairman of the Board of Directors and CEO

Summit Therapeutics Appoints Dr. Maky Zanganeh as Co-CEO & President Bob Duggan Remains Chairman of the Board of Directors and CEO Menlo Park, California, July 26, 2022 - Summit Therapeutics Inc. (NASDAQ: SMMT) announces that Dr. Maky Zanganeh, DDS, MBA, has been appointed as Co-Chief Executive Officer & President, effective immediately. Dr. Zanganeh was formerly the Company?s Chief Operating Offi

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

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): July 25, 2022 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commission

SUMMIT THERAPEUTICS INC. SHARES OF COMMON STOCK ISSUABLE UPON EXERCISE OF SUBSCRIPTION RIGHTS NOMINEE HOLDER CERTIFICATION

THE TERMS AND CONDITIONS OF THE RIGHTS OFFERING ARE SET FORTH IN THE COMPANY?S PROSPECTUS SUPPLEMENT DATED JULY 18, 2022 (THE ?PROSPECTUS SUPPLEMENT?) AND ARE INCORPORATED HEREIN BY REFERENCE.

Summit Therapeutics Announces Commencement of $100 Million Rights Offering

Summit Therapeutics Announces Commencement of $100 Million Rights Offering Menlo Park, California, July 18, 2022 - Summit Therapeutics Inc.

FORM OF INSTRUCTIONS AS TO USE OF SUMMIT THERAPEUTICS INC. NON-TRANSFERABLE SUBSCRIPTION RIGHTS CERTIFICATES PLEASE CONSULT THE SUBSCRIPTION AND INFORMATION AGENT, YOUR BANK OR BROKER FOR ANY QUESTIONS

THE TERMS AND CONDITIONS OF THE RIGHTS OFFERING ARE SET FORTH IN THE COMPANY?S PROSPECTUS SUPPLEMENT DATED JULY 18, 2022 (THE ?PROSPECTUS SUPPLEMENT?) AND ARE INCORPORATED HEREIN BY REFERENCE.

FORM OF LETTER TO BROKERS AND OTHER NOMINEE HOLDERS SUMMIT THERAPEUTICS INC. Subscription Rights to Purchase Shares of Common Stock Offered Pursuant to Subscription Rights Distributed to Stockholders of Summit Therapeutics Inc.

EX-99.3 7 smmt-formoflettertobrokers.htm EX-99.3 FORM OF LETTER TO BROKERS AND OTHER NOMINEE HOLDERS SUMMIT THERAPEUTICS INC. Subscription Rights to Purchase Shares of Common Stock Offered Pursuant to Subscription Rights Distributed to Stockholders of Summit Therapeutics Inc. July 18, 2022 To Securities Dealers, Commercial Banks, Trust Companies and Other Nominees: This letter is being distributed

FORM OF LETTER TO STOCKHOLDERS WHO ARE RECORD HOLDERS SUMMIT THERAPEUTICS INC. Shares of Common Stock Offered Pursuant to Subscription Rights Distributed to Stockholders of Summit Therapeutics Inc.

FORM OF LETTER TO STOCKHOLDERS WHO ARE RECORD HOLDERS SUMMIT THERAPEUTICS INC. Shares of Common Stock Offered Pursuant to Subscription Rights Distributed to Stockholders of Summit Therapeutics Inc. July 18, 2022 Dear Stockholder: Enclosed are materials relating to a rights offering by Summit Therapeutics Inc., a Delaware corporation (?we,? ?us,? ?our,? or the ?Company?), including the prospectus d

Form of Subscription Rights Certificate

THE TERMS AND CONDITIONS OF THE RIGHTS OFFERING ARE SET FORTH IN THE COMPANY?S PROSPECTUS SUPPLEMENT DATED JULY 18, 2022 (THE ?PROSPECTUS SUPPLEMENT?) AND ARE INCORPORATED HEREIN BY REFERENCE.

Summit Therapeutics Inc. Subscription Rights to Purchase Up to 92,592,592 Shares of Common Stock at the Initial Price

Filed Pursuant to Rule 424(b)(4) Registration Statement No. 333-249316 PROSPECTUS SUPPLEMENT (to prospectus dated October 15, 2020) Summit Therapeutics Inc. Subscription Rights to Purchase Up to 92,592,592 Shares of Common Stock at the Initial Price Summit Therapeutics Inc. is distributing at no charge to the holders of our common stock, par value $0.01 per share, non-transferable subscription rig

Financial Statements and Exhibits, Other Events

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): July 18, 2022 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commission

FORM OF LETTER TO CLIENTS OF BROKERS AND OTHER NOMINEE HOLDERS SUMMIT THERAPEUTICS INC. Subscription Rights to Purchase Shares of Common Stock Offered Pursuant to Subscription Rights Distributed to Stockholders of Summit Therapeutics Inc.

FORM OF LETTER TO CLIENTS OF BROKERS AND OTHER NOMINEE HOLDERS SUMMIT THERAPEUTICS INC.

SUMMIT THERAPEUTICS INC. BENEFICIAL OWNER ELECTION FORM

THE TERMS AND CONDITIONS OF THE RIGHTS OFFERING ARE SET FORTH IN THE COMPANY?S PROSPECTUS SUPPLEMENT DATED JULY 18, 2022 (THE ?PROSPECTUS SUPPLEMENT?) AND ARE INCORPORATED HEREIN BY REFERENCE.

Financial Statements and Exhibits, Other Events

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): July 14, 2022 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commission

Summit Therapeutics Provides Update on Ridinilazole

Summit Therapeutics Provides Update on Ridinilazole Menlo Park, California, July 14, 2022 - Summit Therapeutics Inc.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A (Rule 14a-101) Information Required in Proxy Statement Schedule 14a Information Proxy Statement Pursuant to Section 14(a) of The Securities Exchange Act of 1934 (Ame

DEF 14A 1 summit-specialmeetingdefpr.htm DEF 14A UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A (Rule 14a-101) Information Required in Proxy Statement Schedule 14a Information Proxy Statement Pursuant to Section 14(a) of The Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropr

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.     )

PRE 14A 1 summit-specialmeetingproxy.htm PRE 14A UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.     ) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☒ Preliminary Proxy Statement ☐ Confidential, for Use

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of Earliest Event Reported): June 22, 2022 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commission

Financial Statements and Exhibits, Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of Earliest Event Reported): June 16, 2022 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commission

Summit Therapeutics Announces $100 Million Rights Offering

Summit Therapeutics Announces $100 Million Rights Offering Menlo Park, CA, June 22, 2022 - Summit Therapeutics Inc.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) Information Required in Proxy Statement Schedule 14a Information Proxy Statement Pursuant to Section 14(a) of The Securities Exchange Act of 1934 (Ame

DEFA14A 1 summit2022proxydefinitivea.htm DEFA14A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) Information Required in Proxy Statement Schedule 14a Information Proxy Statement Pursuant to Section 14(a) of The Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropr

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of Earliest Event Reported): June 1, 2022 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commission F

Summit Therapeutics Appoints Ankur Dhingra as Chief Financial Officer

Summit Therapeutics Appoints Ankur Dhingra as Chief Financial Officer Cambridge, Massachusetts, June 1, 2022 ? Summit Therapeutics Inc.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ? QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2022 or ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-36866 Summit Th

Financial Statements and Exhibits, Results of Operations and Financial Condition

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): May 11, 2022 Summit Therapeutics Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-36866 37-1979717 (State or Other Jurisdiction of Incorporation) (Commission F

Summit Therapeutics Inc Reports Financial Results and Operational Progress for the First Quarter Ended March 31, 2022

Summit Therapeutics Inc Reports Financial Results and Operational Progress for the First Quarter Ended March 31, 2022 Cambridge, Massachusetts, May 11, 2022 - Summit Therapeutics Inc.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) Information Required in Proxy Statement Schedule 14a Information Proxy Statement Pursuant to Section 14(a) of The Securities Exchange Act of 1934 (Ame

DEF 14A 1 summit2022proxydraft.htm DEF 14A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) Information Required in Proxy Statement Schedule 14a Information Proxy Statement Pursuant to Section 14(a) of The Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant Filed by a Party other than the Registrant Check the appropriate box:

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM S-8 REGISTRATION STATEMENT THE SECURITIES ACT OF 1933 SUMMIT THERAPEUTICS INC. (Exact Name of Registrant as Specified in Its Charter)

Registration No. 333- UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM S-8 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 SUMMIT THERAPEUTICS INC. (Exact Name of Registrant as Specified in Its Charter) Delaware 37-1979717 (State or Other Jurisdiction of Incorporation or Organization) (I.R.S. Employer Identification No.) One Broadway, 14th Floor Cambridge, MA 02

Filing Fee Table

EXHIBIT 107 Calculation of Filing Fee Tables S-8 (Form Type) SUMMIT THERAPEUTICS INC.