Form 8-K - 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): 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)	(Commission File Number)	(IRS Employer Identification No.)

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

Registrant’s Telephone Number, Including Area Code: (650) 460-8308


2882 Sand Hill Road, Suite 106, Menlo Park, CA 94025
(Former Name or Former Address, If Changed Since Last Report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:


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

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐


Item 2.02			Results of Operations and Financial Condition.

As of December 31, 2023, the Company's preliminary unaudited balance of cash, cash equivalents, and short-term investments was no less than $186 million. This amount is preliminary and is subject to completion of financial closing procedures. As a result, this amount may differ materially from the amount that will be reflected in the Company’s consolidated financial statements for the year ended December 31, 2023.

The information in Item 2.02 of this Current Report on Form 8-K is intended to be furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”) or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended (the “Securities Act”), or the Exchange Act, except as expressly set forth by specific reference in such filing.

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


Item 7.01			Regulation FD Disclosure.

On January 8, 2024, Summit Therapeutics, Inc. (the “Company”) issued a press release announcing substantial updates to the development of ivonescimab, as well as near-term corporate catalysts that it will present at the 42nd Annual J.P. Morgan Healthcare Conference. A copy of the press release is attached as Exhibit 99.1 to this current Report on Form 8-K and is incorporated by reference herein. A copy of the presentation is attached as Exhibit 99.2 to this current Report on Form 8-K and is incorporated by reference herein.

The information in this Item 7.01 of this Current Report on Form 8-K and Exhibit 99.2 attached hereto is intended to be furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such filing.


Item 9.01			Financial Statements and Exhibits.

(d) Exhibits


Exhibit Number			Description
99.1			Press Release, dated January 08, 2024
99.2			Investor Presentation Slides made available on January 8, 2024
104			Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, hereunto duly authorized.


	SUMMIT THERAPEUTICS INC.


Date: January 8, 2024	By:	/s/ Ankur Dhingra
		Chief Financial Officer
		(Principal Financial Officer)

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 Patients Catalyst Events Expected in Q2 2024 for Two Randomized Phase III Trials Evaluating Ivonescimab in China Conducted by Akeso, including Head-to-Head vs. Pembrolizumab Miami, FL, January 08, 2024 – Summit Therapeutics Inc. (NASDAQ: SMMT) (“Summit,” “we,” or the “Company”) today announced substantial updates to the promising development of ivonescimab, as well as near-term corporate catalysts that it will present at the 42nd Annual J.P. Morgan Healthcare Conference on Tuesday, January 09, 2024, at 1:30 PM PT in San Francisco, CA. AK112-201 (NCT04736823) is an open-label Phase II study evaluating ivonescimab plus chemotherapy across three cohorts of patients. In part, data generated from this trial has supported Summit’s decision to advance ivonescimab into two global Phase III clinical trials. Updated data includes patients from Cohorts 1 & 2 of this study: • Cohort 1: Patients with first line advanced or metastatic non-small cell lung cancer (NSCLC) without actionable genomic alterations (i.e., patients’ tumors do not have actionable mutations in endothelial growth factor receptor (EGFR) or anaplastic lymphoma kinase (ALK)). o The updated data centers on the 63 patients whose tumor is of squamous histology. • Cohort 2: Patients with second or third line advanced or metastatic NSCLC whose tumors are positive for EGFR mutations (EGFRm) and have progressed following an EGFR tyrosine kinase inhibitor (TKI) (n=19). Notably, the estimated 1-year overall survival rate was 85.6%, and the 2-year overall survival rate was 64.8% for patients in Cohort 1 with squamous histology NSCLC. After a median follow-up time of 21.0 months, the median overall survival (OS) was not reached.1 The frequency of treatment-related adverse events (TRAEs) leading to discontinuation of ivonescimab was 11%; there were no TRAEs leading to the death of a patient. The most frequent treatment-emergent adverse events were anemia, decreased neutrophil counts, and decreased white-blood cell counts. The 19 patients in Cohort 2, primarily second or third line patients with EGFRm NSCLC, demonstrated a median overall survival of 22.5 months. After a median follow-up time of 25.8 months, the estimated 1-year overall survival rate was 74%.1 Ivonescimab had an acceptable safety profile in combination with platinum-doublet chemotherapy for patients with advanced or metastatic NSCLC who had progressed following an EGFR-TKI. There were no TRAEs leading to permanent discontinuation of therapy or patient death. 1 Akeso, Inc. Press Release, January 8, 2024.

2 AK112-201 Phase II Trial1 Cohort 1: 1L SQ-NSCLC only (n=63) Cohort 2: 2L / 3L+ EGFR-TKI Progressors NSCLC (n=19) Overall Response Rate (ORR)* 67% 68% Disease Control Rate (DCR)* 95% 95% Median Duration of Response (DOR)* 12.8 months 8.7 months Median PFS (95% CI) 11.1 months (9.5 – 16.3 months) 8.5 months (5.5 – 13.3 months) Median OS (95% CI) Not Reached (22.5 months – NE**) 22.5 months (10.4 months – NE**) 12-month OS Rate 85.6% 73.7% 24-month OS Rate 64.8% 40.9% * Confirmed responses for patients with at least one post-baseline scan; SQ-NSCLC n=60; EGFR-TKI n=19 ** NE – Not Established AK112-201 is a clinical trial that is sponsored and conducted in China by our collaboration and licensing partner, Akeso, Inc. (HKEX Code: 9926.HK). The aforementioned data related to AK112-201 was generated and analyzed by Akeso. Summit is enrolling patients in two global Phase III clinical trials involving ivonescimab: • HARMONi intends to evaluate ivonescimab combined with chemotherapy compared to a placebo plus chemotherapy in patients with EGFR-mutated, locally advanced or metastatic non-squamous NSCLC who have progressed after treatment with a third-generation EGFR TKI (NCT05184712), and • HARMONi-3 is designed to evaluate ivonescimab combined with chemotherapy compared to pembrolizumab combined with chemotherapy in patients with 1L metastatic squamous NSCLC (NCT05899608). Near-Term Catalyst Events for Summit & the Development of Ivonescimab In addition to the ongoing Phase III clinical trials sponsored by Summit, Akeso is sponsoring four Phase III clinical trials investigating ivonescimab in China in NSCLC. Near-term catalyst events for both Summit and Akeso include expected key milestones for two of Akeso’s Phase III randomized clinical trials evaluating ivonescimab in China: • AK112-301, which reflects the patient population of Summit’s HARMONi trial, was submitted for marketing approval to the Chinese health authority in 2023, and a decision from the Chinese Center for Drug Evaluation (CDE) is expected in Q2 2024, along with a read-out of topline data from the study by Akeso, and • AK112-303, which is evaluating monotherapy ivonescimab vs. pembrolizumab in 1L NSCLC patients whose tumors have a PD-L1 TPS >1%, has a planned interim analysis by Akeso, which is expected to be completed in Q2 2024. Both studies represent ivonescimab in randomized, pivotal clinical trials against the standard of care in their respective settings. “As the data continues to mature in Phase II studies evaluating ivonescimab, including data related to the survival of patients impacted by these terrible diseases, our belief and conviction in ivonescimab is reinforced,” stated Summit’s Chief Executive Officers, Robert W. Duggan and Dr. Maky Zanganeh. “The speed and purpose with which Team Summit acts reflect the opportunity to accomplish our mission of making a significant difference in the

3 lives of patients facing difficult odds from a cancer diagnosis. We believe that the potential created by the differentiated mechanism of action and supporting trial data for ivonescimab deserves a swift development plan to bring ivonescimab to those patients who can benefit most. We are honored to work with our partners at Akeso to continue to strive to achieve this common goal.” In addition to live attendance at the JPM 2024 conference, the audio presentation will be available live from our website: www.smmttx.com. Update Regarding Current Financial Position As of December 31, 2023, the company’s preliminary unaudited balance of cash, cash equivalents, and short- term investments was no less than $186 million -. This amount is preliminary and is subject to completion of financial closing procedures. As a result, this amount may differ materially from the amount that will be reflected in the Company’s consolidated financial statements for the year ended December 31, 2023. About Ivonescimab Ivonescimab, known as SMT112 in Summit’s license territories, the United States, Canada, Europe, and Japan, and as AK112 in China and Australia, is a novel, potential first-in-class investigational bispecific antibody combining the effects of immunotherapy via a blockade of PD-1 with the anti-angiogenesis effects associated with blocking VEGF into a single molecule. Ivonescimab displays unique cooperative binding to each of its intended targets with higher affinity when in the presence of both PD-1 and VEGF. This could differentiate ivonescimab as there is potentially higher expression (presence) of both PD-1 and VEGF in tumor tissue and the tumor microenvironment (TME) as compared to normal tissue in the body. Ivonescimab’s tetravalent structure (four binding sites) enables higher avidity (accumulated strength of multiple binding interactions) in the tumor microenvironment with over 18 fold increased binding affinity to PD-1 in the presence of VEGF in vitro, and over 4 times increased binding affinity to VEGF in the presence of PD-1 in vitro.2 This tetravalent structure, the intentional novel design of the molecule, and bringing these two targets into a single bispecific antibody with cooperative binding qualities have the potential to direct ivonescimab to the tumor tissue versus healthy tissue. The intent of this design is to improve upon previously established efficacy thresholds, in addition to side effects and safety profiles associated with these targets. Ivonescimab was discovered by Akeso Inc. (HKEX Code: 9926.HK) and is currently engaged in multiple Phase III clinical trials. Summit has begun its clinical development of ivonescimab in NSCLC, commencing enrollment in 2023 in its two Phase III clinical trials. Over 1,600 patients have been treated with ivonescimab in clinical studies in China and Australia, with enrollment beginning in 2023 in Summit's license territories. About Lung Cancer Lung cancer is believed to impact approximately 600,000 people across the United States, United Kingdom, Spain, France, Italy, Germany, and Japan.3 NSCLC is the most prevalent type of lung cancer and represents approximately 80% to 85% of all incidences.4 Among patients with non-squamous NSCLC, approximately 15% 2 Zhong, et al, SITC 2023 3 American Cancer Society: www.cancer.org/cancer/types/lung-cancer/about/key-statistics.html (Accessed Jan 2024); World Health Organization: International Agency for Research on Cancer, Globocan data by country (UK, Spain, France, Italy, Germany); Japan National Cancer Registry. 4 Schabath MB, Cote ML. Cancer Progress and Priorities: Lung Cancer. Cancer Epidemiology, Biomarkers & Prevention. (2019).

4 have EGFR-sensitizing mutations in the United States and Europe.5 Patients with squamous histology represent approximately 25% to 30% of NSCLC patients. 6 About Summit Therapeutics Summit was founded in 2003 and our shares are listed on the Nasdaq Global Market (symbol ‘SMMT’). We are headquartered in Miami, Florida, and we have additional offices in Menlo Park, California, and Oxford, UK. Summit’s mission, in part, is to develop patient, physician, caregiver, and societal-friendly medicinal therapies intended to improve quality of life, increase potential duration of life, and resolve serious unmet medical needs. For more information, please visit https://www.smmttx.com and follow us on X (formerly Twitter) @summitplc. Contact Summit Investor Relations: Dave Gancarz Chief Business & Strategy Officer investors@smmttx.com Summit Forward-looking Statements Any statements in this press release about the Company’s future expectations, plans and prospects, including but not limited to, statements about the clinical and preclinical development of the Company’s product candidates, entry into and actions related to the Company’s partnership with Akeso Inc., the therapeutic potential of the Company’s product candidates, the potential commercialization of the Company’s product candidates, the timing of initiation, completion and availability of data from clinical trials, the potential submission of applications for marketing approvals, potential acquisitions and other statements containing the words "anticipate," "believe," "continue," "could," "estimate," "expect," "intend," "may," "plan," "potential," "predict," "project," "should," "target," "would," and similar expressions, constitute forward-looking statements within the meaning of The Private Securities Litigation Reform Act of 1995. Actual results may differ materially from those indicated by such forward- looking statements as a result of various important factors, including the results of our evaluation of the underlying data in connection with the development and commercialization activities for ivonescimab, the outcome of discussions with regulatory authorities, including the Food and Drug Administration, the uncertainties inherent in the initiation of future clinical trials, availability and timing of data from ongoing and future clinical trials, the results of such trials, and their success, and global public health crises, that may affect timing and status of our clinical trials and operations, whether preliminary results from a clinical trial will be predictive of the final results of that trial or whether results of early clinical trials or preclinical studies will be indicative of the results of later clinical trials, whether business development opportunities to expand the Company’s pipeline of drug candidates, including without limitation, through potential acquisitions of, and/or collaborations with, other entities occur, expectations for regulatory approvals, laws and regulations affecting government contracts and funding awards, availability of funding sufficient for the Company’s foreseeable and unforeseeable operating expenses and capital expenditure requirements and other factors discussed in the "Risk Factors" section of filings that the Company makes with the Securities and Exchange Commission. Any change to our ongoing trials could cause delays, affect our future expenses, and add uncertainty to our commercialization efforts, as well as to affect the likelihood of the successful completion of clinical development of ivonescimab. Accordingly, readers should not place undue reliance on 5 About EGFR-Positive Lung Cancer | Navigating EGFR (lungevity.org) 6 Schabath MB, Cote ML. Cancer Progress and Priorities: Lung Cancer. Cancer Epidemiology, Biomarkers & Prevention. (2019).

5 forward-looking statements or information. In addition, any forward-looking statements included in this press release represent the Company’s views only as of the date of this release and should not be relied upon as representing the Company’s views as of any subsequent date. The Company specifically disclaims any obligation to update any forward-looking statements included in this press release.

6 Appendix: Glossary of Critical Terms Contained Herein Affinity – Affinity is the strength of binding of a molecule, such as a protein or antibody, to another molecule, such as a ligand. Avidity – Avidity is the accumulated strength of multiple binding interactions. Angiogenesis – Angiogenesis is the development, formation, and maintenance of blood vessel structures. Without sufficient blood flow, tissue may experience hypoxia (insufficient oxygen) or lack of nutrition, which may cause cell death.7 Cooperative binding – Cooperative binding occurs when the number of binding sites on the molecule that can be occupied by a specific ligand (e.g., protein) is impacted by the ligand’s concentration. For example, this can be due to an affinity for the ligand that depends on the amount of ligand bound or the binding strength of the molecule to one ligand based on the concentration of another ligand, increasing the chance of another ligand binding to the compound.8 Immunotherapy – Immunotherapy is a type of treatment, including cancer treatments, that help a person’s immune system fight cancer. Examples include anti-PD-1 therapies.9 PD-1 – Programmed cell Death protein 1 is a protein on the surface of T cells and other cells. PD-1 plays a key role in reducing the regulation of ineffective or harmful immune responses and maintaining immune tolerance. However, with respect to cancer tumor cells, PD-1 can act as a stopping mechanism (a brake or checkpoint) by binding to PD-L1 ligands that exist on tumor cells and preventing the T cells from targeting cancerous tumor cells.10 PD-L1 – Programmed cell Death Ligand 1 is expressed by cancerous tumor cells as an adaptive immune mechanism to escape anti-tumor responses, thus believed to suppress the immune system’s response to the presence of cancer cells. 11 PD-L1 TPS – PD-L1 Tumor Proportion Score represents the percentage of tumor cells that express PD-L1 proteins. PFS – Progression-Free Survival. SQ-NSCLC – Non-small cell lung cancer tumors of squamous histology. T Cells – T cells are a type of white blood cell that is a component of the immune system that, in general, fights against infection and harmful cells like tumor cells.12 Tetravalent – A tetravalent molecule has four binding sites or regions. 7 Shibuya M. Vascular Endothelial Growth Factor (VEGF) and Its Receptor (VEGFR) Signaling in Angiogenesis: A Crucial Target for Anti- and Pro- Angiogenic Therapies. Genes Cancer. 2011 Dec;2(12):1097-105. 8 Stefan MI, Le Novère N. Cooperative binding. PLoS Comput Biol. 2013;9(6) 9 US National Cancer Institute, a part of the National Institute of Health (NIH). https://www.cancer.gov/about- cancer/treatment/types/immunotherapy. Accessed October 2023. 10 Han Y, et al. PD-1/PD-L1 Pathway: Current Researches in Cancer. Am J Cancer Res. 2020 Mar 1;10(3):727-742. 11 Han Y, et al. PD-1/PD-L1 Pathway: Current Researches in Cancer. Am J Cancer Res. 2020 Mar 1;10(3):727-742. 12 Cleveland Clinic. https://my.clevelandclinic.org/health/body/24630-t-cells. Accessed October 2023.

7 Tumor Microenvironment – The tumor microenvironment is the ecosystem that surrounds a tumor inside the body. It includes immune cells, the extracellular matrix, blood vessels and other cells, like fibroblasts. A tumor and its microenvironment constantly interact and influence each other, either positively or negatively.13 VEGF – Vascular Endothelial Growth Factor is a signaling protein that promotes angiogenesis. 14 13 MD Anderson Cancer Center. https://www.mdanderson.org/cancerwise/what-is-the-tumor-microenvironment-3-things-to-know.h00- 159460056.html. Accessed October 2023. 14 Shibuya M. Vascular Endothelial Growth Factor (VEGF) and Its Receptor (VEGFR) Signaling in Angiogenesis: A Crucial Target for Anti- and Pro- Angiogenic Therapies. Genes Cancer. 2011 Dec;2(12):1097-105.

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 42nd Annual Healthcare Conference, January 2024 Any statements in this presentation about the Company’s future expectations, plans and prospects, including but not limited to, statements about the clinical and preclinical development of the Company’s product candidates, entry into and actions related to the Company’s partnership with Akeso Inc., the therapeutic potential of the Company’s product candidates, the potential commercialization of the Company’s product candidates, the timing of initiation, completion and availability of data from clinical trials, the potential submission of applications for marketing approvals, potential acquisitions and other statements containing the words "anticipate," "believe," "continue," "could," "estimate," "expect," "intend," "may," "plan," "potential," "predict," "project," "should," "target," "would," and similar expressions, constitute forward-looking statements within the meaning of The Private Securities Litigation Reform Act of 1995. Actual results may differ materially from those indicated by such forward-looking statements as a result of various important factors, including the results of our evaluation of the underlying data in connection with the development and commercialization activities for ivonescimab, the outcome of discussions with regulatory authorities, including the Food and Drug Administration, the uncertainties inherent in the initiation of future clinical trials, availability and timing of data from ongoing and future clinical trials, the results of such trials, and their success, and global public health crises that may affect timing and status of our clinical trials and operations, whether preliminary results from a clinical trial will be predictive of the final results of that trial or whether results of early clinical trials or preclinical studies will be indicative of the results of later clinical trials, whether business development opportunities to expand the Company’s pipeline of drug candidates, including without limitation, through potential acquisitions of, and/or collaborations with, other entities occur, expectations for regulatory approvals, laws and regulations affecting government contracts and funding awards, availability of funding sufficient for the Company’s foreseeable and unforeseeable operating expenses and capital expenditure requirements and other factors discussed in the "Risk Factors" section of filings that the Company makes with the Securities and Exchange Commission. Any change to our ongoing trials could cause delays, affect our future expenses, and add uncertainty to our commercialization efforts, as well as to affect the likelihood of the successful completion of clinical development of ivonescimab. Accordingly, the audience should not place undue reliance on forward-looking statements or information. In addition, any forward-looking statements included in this presentation represent the Company’s views only as of the date of this presentation and should not be relied upon as representing the Company’s views as of any subsequent date. The Company specifically disclaims any obligation to update any forward-looking statements included in this presentation.

Company Details Focus ONCOLOGY Partnership Akeso Inc. Summit License Territories United States, Canada, Europe, Japan Chief Executive Officers Bob Duggan Chairman & CEO Dr. Maky Zanganeh CEO & President NASDAQ SMMT Market Cap $1.83B* Cash $186M* Employees 111† Offices Miami, FL Menlo Park, CA Oxford, UK …Improve quality of life, increase potential duration of life, and resolve serious medical healthcare needs… MISSION Unmatched high-speed execution, proven track record FOCUSED ON PATIENTS FIRST LEADERSHIP Lead Compound: Ivonescimab Only Phase III PD-1/VEGF Bispecific Antibody in Summit’s License Territories* 2024 Focus Execute on Phase III clinical trials Expand clinical development plan Summit Therapeutics *As of December 31, 2023; †As of January 8, 2024 3 Summit Proprietary Information - Do Not Copy, Photograph or Distribute J.P. Morgan 42nd Annual Healthcare Conference, January 2024 Ivonescimab is an investigational therapy that is not approved by any regulatory authority. It is currently being investigated in Phase III clinical studies. *There are no known PD-1-based bispecific antibodies approved by the U.S. Food and Drug Administration (“FDA”) or the European Medicines Agency (“EMA”).

Partnership with An Aligned Mission Bringing ivonescimab to patients around the world Summit is actively recruiting two Phase III NSCLC clinical trials LEADING BIOPHARMA COMPANY IN CHINA Michelle Xia, Ph.D. Co-Founder, Chairwoman, President and CEO Over 2,800 Employees End-to-end In-house Capabilities INNOVATOR1,2 World’s first marketed PD-1 bispecific (cadonilimab)3 3 commercial drugs in China 120+ worldwide clinical trials* 30+ drug candidates 19 clinical-stage candidates 6+ bispecific antibodies 1.Akeso Press Release (2022-12-06), 2. Akeso website accessed on 12.1.23, 3. https://scrip.citeline.com/SC146649/China-Approves- Worlds-First-Bispecific-IO-Drug-Amid-PD-1L1-Glut. Accessed 1.4.24. *Including ISTs with Akeso products. NSCLC: Non-small Cell Lung Cancer Globally, 1,600+ patients treated with ivonescimab across all trials to date 4 Summit Proprietary Information - Do Not Copy, Photograph or Distribute J.P. Morgan 42nd Annual Healthcare Conference, January 2024 Ivonescimab is an investigational therapy that is not approved by any regulatory authority. It is currently being investigated in Phase III clinical studies.

Shaping the Path to Become a Commercial Entity SITC: Society for Immunotherapy of Cancer; MOA: Mechanism of Action; ASCO: American Society of Clinical Oncology; NSCLC: Non-small Cell Lung Cancer; EORTC: European Organisation for Research and Treatment of Cancer; NCI: National Cancer Institute; AACR: American Association for Cancer Research; IST: Investigator Sponsored Trials Multiple Meetings First Patient In First Patient In Accepted IST Proposals (ivonescimab) Partnership Consummated Q1 2023 Q2 2023 Q3 2023 Q4 2023 Raised $500M MOA (Poster) EORTC-NCI-AACR MOA (Poster) Phase II Data (Article) NSCLC Phase II Data (Poster) 5 Summit Proprietary Information - Do Not Copy, Photograph or Distribute J.P. Morgan 42nd Annual Healthcare Conference, January 2024 Ivonescimab is an investigational therapy that is not approved by any regulatory authority. It is currently being investigated in Phase III clinical studies. T H E L AN C E T SITC

Ivonescimab: Mechanism of Action

Designed to Potentially Improve the Balance of Anti-tumor Activity & Safety1,2 *There are no known PD-1-based bispecific antibodies approved by the U.S. Food and Drug Administration (“FDA”) or the European Medicines Agency (“EMA”). Ivonescimab is an investigational therapy that is not approved by any regulatory authority. Ivonescimab is currently being investigated in Phase III clinical studies. Ivonescimab First-in-Class* PD-1/VEGF Brings two validated oncologic mechanisms into ONE novel tetravalent molecule3,4,5 Potential to Steer to Tumor vs. Healthy Tissue Where there are higher levels of PD-1 & VEGF1,2,7,8 Only Phase III PD-1/VEGF Bispecific In clinical development in North America, Europe and Japan* Cooperative Binding Simultaneous blocking of PD-1 & VEGF 1,3,6 Increased: Avidity in TME7 Activity of T Cells7,8 (in vitro) 7 Summit Proprietary Information - Do Not Copy, Photograph or Distribute J.P. Morgan 42nd Annual Healthcare Conference, January 2024 1. Zhao Y, et al. eClinicalMedicine. 2023; 3(62): 102106. 2. Zhou C, et al. J Clin Oncol. 2022;40:16_suppl, 9040. 3. Manegold C, et al. J Thorac Oncol 2017;12(2):194-207 4. Pardoll, D. Nat Rev Cancer 2012;12(4):252-64 5.Tamura R, et al. Med Oncol 2020;37(1):2 6.Data on File. [14, 15] Summit Therapeutics Inc. 7. Zhong T, et al. AACR- NCI-EORTC International Conference 2023.Poster #B123, Abstract #35333, Boston, MA, USA, 8. Zhong T, et al. JITC 2022;10(2):521 TME: Tumor Microenvironment Anti-VEGF Anti-PD-1 Linkers

VEGF Dimer PD-1 Receptor in T Cell Increased Avidity in TME VEGF increases affinity to PD-1 by >18X4 PD-1 increases affinity to VEGF by >4X4 (in vitro) Enhanced Activity of T Cells VEGF dimer leads to potential interconnection of ivonescimab molecules, which may increase activity of T cells4,5 Ivonescimab is an investigational therapy that is not approved by any regulatory authority. Ivonescimab is currently being investigated in Phase III clinical studies Simultaneous blocking of PD-1 & VEGF1,2,3 Ivonescimab 8 Summit Proprietary Information - Do Not Copy, Photograph or Distribute J.P. Morgan 42nd Annual Healthcare Conference, January 2024 Cooperative Binding Greater Than the Sum of Its Parts 1. Zhao Y. et al., eClinicalMedicine. 2023; 3(62): 102106.,; 2. Manegold C, et al. J Thorac Oncol 2017;12(2):194-207 ; 3. Data on File. [14, 15] Summit Therapeutics Inc.; 4. Zhong T, et al. AACR-NCI-EORTC International Conference 2023.Poster #B123,Abstract #35333, Boston, MA, USA,; 5. Zhong T, et al. JITC 2022;10(2):521.

Ivonescimab Clinical Data

AK112-201 Cohort 1: Squamous only; ivonescimab + chemo Phase II, N=63 ORR† 67% DCR† 95% mDOR† 12.8m mPFS [95% CI] 11.1m [9.5 – 16.3] KEYNOTE-407 China Extension4 pembrolizumab + chemo; randomized Phase III, N=65 KEYNOTE-407 Global5 pembrolizumab + chemo; randomized Phase III, N=278 ORR† 80% 63% DCR† 91% 86% mDOR 7.1m 8.8m mPFS [95% CI] 8.3m [6.2 – 10.5] 8.0m [6.3 – 8.4] Ivonescimab is an investigational therapy that is not approved by any regulatory authority. It is currently being investigated in Phase III clinical studies. Data generated and analyzed by Akeso. Percent Changes from Baseline in Target Lesions Sum of Diameters (N=60) ORR: Overall Response Rate, DCR: Disease Control Rate; mDOR: median Duration of Response, mPFS: median Progression Free Survival, DCO: data cutoff, NSCLC: Non-small Cell Lung Cancer, 1L: First Line, CI: Confidence Interval, SQ: Squamous, mFU: median follow-up, chemo: chemotherapy, m: month 1. Zhang L, et al., ASCO 2023 poster #9087 2. Akeso Press Release, January 7, 2024 3. Data on File 8. Summit Therapeutics Inc. 4. Cheng et. al. JTO Clin Res Rep (2021) 5. Paz-Ares, et. al. Journal of Thoracic Onc (2020) 1L Adv/Metastatic Squamous NSCLC1,2,3 AK112-201 includes 10 mg/kg dosing (16%) and 20 mg/kg dosing (84%) of ivonescimab 10 Summit Proprietary Information - Do Not Copy, Photograph or Distribute J.P. Morgan 42nd Annual Healthcare Conference, January 2024 Established Standard of Care Presentation exclusively for purposes of evaluating the landscape for ivonescimab † Includes subjects with at least one post-baseline tumor assessment, ORR based on confirmed BOR; N=60 evaluable for response Phase II Ivonescimab + Chemo Median follow up 21.0 months (DCO:10/10/2023)

OS: overall survival, DCO: data cutoff NSCLC: Non-small Cell Lung Cancer, 1L: First Line, CI: Confidence Interval, SQ: Squamous, pembro: pembrolizumab, chemo: chemotherapy, NE: Not Established, NR Not Reached, TRAEs: Treatment Related Adverse Events Ivonescimab is an investigational therapy that is not approved by any regulatory authority. It is currently being investigated in Phase III clinical studies. Data generated and analyzed by Akeso. KEYNOTE-407 China Extension4 pembrolizumab + chemo; randomized Phase III, N=65 KEYNOTE-407 Global5 pembrolizumab + chemo; randomized Phase III, N=278 mOS 30.1m [18.2 – NR] 17.2m [14.4 – 19.7) 12m OS 78.5% 64.7% 24m OS 56.9% 36.0% 1. Zhang L, et al., ASCO 2023 poster #9087 2. Akeso Press Release, January 7, 2024 3. Data on File 8. Summit Therapeutics Inc. 4. Cheng, et. al. JTO Clin Res Rep (2021) 5. Novello, et. al. J Clin Oncol 41, no. 11 (2023) 1L Adv/Metastatic Squamous NSCLC1,2,3 Phase II Ivonescimab + Chemo Median follow up 21.0 months (DCO:10/10/2023) 11 Summit Proprietary Information - Do Not Copy, Photograph or Distribute J.P. Morgan 42nd Annual Healthcare Conference, January 2024 AK112-201 Cohort 1: Squamous only ivonescimab + chemo Phase II, N=63 mOS Not Reached [22.5 – NE] 12m OS 85.6% 24m OS 64.8% AK112-201 includes 10 mg/kg dosing (16%) and 20 mg/kg dosing (84%) of ivonescimab Established Standard of Care Presentation exclusively for purposes of evaluating the landscape for ivonescimab

MARIPOSA-24 amivantamab + chemo; randomized Phase III, N=131 KEYNOTE-7895 pembrolizumab + chemo; randomized Phase III, N=245 KEYNOTE-7895 placebo + chemo; randomized Phase III, N=247 ORR† [95% CI] 64.1% [55 – 72] 29.0% [23 – 35] 27.1% [22 – 33] mDOR 6.9m 6.3m 5.6m mPFS [95% CI] 6.3m [5.6 – 8.4] 5.6m [5.5 – 5.8] 5.5m [5.4 – 5.6] AK112-201 Cohort 2 (EGFR+) ivonescimab + chemo Phase II, N=19 ORR† [95% CI] 68.4% [43 – 87] mDOR† 8.7m mPFS [95% CI] 8.5m [5.5 – 13.3] 1. Akeso Press Release, January 7, 2024 2. Data on File 9. Summit Therapeutics Inc. 3. Zhang L, et al., ASCO 2023 poster #9087 4. Passaro A, et al. Ann Onc. 2023. 5. Yang, Oral LBA9000, ASCO 2023 Ivonescimab is an investigational therapy that is not approved by any regulatory authority. It is currently being investigated in Phase III clinical studies. Data generated and analyzed by Akeso. ORR: Overall Response Rate, mDOR: median Duration of Response, mPFS: median Progression Free Survival, DCO: data cutoff, NSCLC: Non-small Cell Lung Cancer, 1L: First Line, CI: Confidence Interval, chemo: chemotherapy, m: month 2L+ EGFR-TKI Progressors1,2,3 Phase II Ivonescimab + Chemo Median follow up 25.8 months (DCO:10/10/2023) Percent Changes from Baseline in Target Lesions Sum of Diameters Full Analysis Set (N=19) † Includes subjects with at least one post-baseline tumor assessment, ORR based on confirmed BOR 12 Summit Proprietary Information - Do Not Copy, Photograph or Distribute J.P. Morgan 42nd Annual Healthcare Conference, January 2024 AK112-201 includes 10 mg/kg dosing (53%) and 20 mg/kg dosing (47%) of ivonescimab Relevant Phase III Studies Not Currently Approved in this Setting Presentation exclusively for purposes of evaluating the landscape for ivonescimab

MARIPOSA-24 amivantamab + chemo; randomized Phase III, N=131 KEYNOTE-7895 pembrolizumab + chemo; randomized Phase III, N=245 KEYNOTE-7895 placebo + chemo; randomized Phase III, N=247 mOS NR 15.9m [13.7 – 18.8] 14.7m [12.7 – 17.1] 12m OS NR 62% 59% AK112-201 Cohort 2 (EGFR+) ivonescimab + chemo Phase II, N=19 mOS 22.5m [10.4 – NE] 12m OS 74% mOS: median Overall Survival, OS: Overall Survival, chemo: chemotherapy, m: month, NR: not reached, NE: not established, TRAEs: Treatment Related Adverse Events Ivonescimab is an investigational therapy that is not approved by any regulatory authority. It is currently being investigated in Phase III clinical studies. Data generated and analyzed by Akeso. Overall Survival (OS) for EGFR-TKI Progressors (N=19) 2L+ EGFR-TKI Progressors1,2,3 Phase II Ivonescimab + Chemo Median follow up 25.8 months (DCO:10/10/2023) 13 Summit Proprietary Information - Do Not Copy, Photograph or Distribute J.P. Morgan 42nd Annual Healthcare Conference, January 2024 Relevant Phase III Studies Not Currently Approved in this Setting Presentation exclusively for purposes of evaluating the landscape for ivonescimab 1. Akeso Press Release, January 7, 2024 2. Data on File 9. Summit Therapeutics Inc. 3. Zhang L, et al., ASCO 2023 poster #9087 4. Passaro A, et al. Ann Onc. 2023. 5. Yang, Oral LBA9000, ASCO 2023 AK112-201 includes 10 mg/kg dosing (53%) and 20 mg/kg dosing (47%) of ivonescimab

Ivonescimab Phase II Safety Data in Key NSCLC Settings Ivonescimab Demonstrated a Tolerable Safety Profile DCO: 10/10/2023 14 Number (%) Grade >3 TRAE 28 (44.4) TRAE leading to discontinuation of ivonescimab 7 (11.1) TRAE leading to death 0 Number (%) Grade >3 TRAE 7 (36.8) TRAE leading to discontinuation of ivonescimab 0 TRAE leading to death 0 Data generated based on Akeso sponsored studies. Ivonescimab is an investigational therapy that is not approved by any regulatory authority. It is currently being investigated in Phase III clinical studies. Top Treatment-Emergent Adverse Events All TEAE 62 (98.4) Anemia 39 (61.9) Neutropenia 28 (44.4) Leukopenia 26 (41.3) Top Treatment-Emergent Adverse Events All TEAE 19 (100.0) Anemia 13 (68.4) Neutropenia 12 (63.2) ALT increased 12 (63.2) Summit Proprietary Information - Do Not Copy, Photograph or Distribute J.P. Morgan 42nd Annual Healthcare Conference, January 2024 1L Squamous Ivonescimab + Chemotherapy (n=63) 2L+ EGFRm Ivonescimab + Chemotherapy (n=19) 1. Data on File 4. Summit Therapeutics Inc.

Ivonescimab Opportunity

There are no PD-1/VEGF bispecific antibodies approved or in Phase III in Summit’s license territories Approved Anti PD-(L)1 Therapies Approved Anti-VEGF Therapies There are 50+ Approved Indications for PD-(L)1 & VEGF Therapies Data from cancer.gov updated 2023 16 Summit Proprietary Information - Do Not Copy, Photograph or Distribute J.P. Morgan 42nd Annual Healthcare Conference, January 2024 Primary Peritoneal Cancer Glioblastoma Esophageal Cancer Melanoma Basel Cell Carcinoma Cervical Cancer Biliary Tract Carcinoma Classic Hodgkin Lymphoma Colorectal Cancer Cutaneous Squamous Cell Cancer Endometrial Carcinoma Gastric Cancer Gastroesophageal Junction Cancer Head & Neck Squamous Cell Cancer Hepatocellular Carcinoma Malignant Pleural Mesothelioma Merkel Cell Carcinoma Nasopharyngeal Carcinoma Non-Small Cell Lung Cancer Primary Mediastinal Large B-Cell Lymphoma Renal Cell Carcinoma Small Cell Lung Cancer Urothelial Carcinoma Triple-Negative Breast Cancer NSCLC (Non-Squamous) Ovarian Cancer Pancreatic Cancer Thyroid Cancer MSI-H or dMMR Colorectal Cancer Peritoneal Mesothelioma Pericardial Mesothelioma Testicular Mesothelioma MSI-H or dMMR Endometrial Carcinoma MSI-H or dMMR Gastric Cancer TMB-H Cholangiocarcinoma TMB-H Gallbladder Cancer TMB-H Melanoma TMB-H Colorectal Cancer TMB-H Gastric Cancer Epithelial Ovarian Fallopian Tube Alveolar Soft Part Sarcoma Approved Anti PD-(L)1 & Anti-VEGF Therapies

Focusing On High Unmet Needs – Near Term * UK, Germany, France, Italy, Spain 1 American Cancer Society: www.cancer.org/cancer/types/lung-cancer/about/key-statistics.html (Accessed Jan 2024); World Health Organization: International Agency for Research on Cancer, Globocan data by country (UK, Spain, France, Italy, Germany); Japan National Cancer Registry.; 2 Represents 2L+ EGFRm patients in above jurisdictions; ~14k patients in US; Sources: American Cancer Society; Zhang, et al; Oncotarget (2016); Uhlig, et al. JAMA Netw Open (2019); Ganti, et al. JAMA Oncol (2021); Japan National Cancer Registry; Decision Resources Group; AZ Epidemiology Data (June 2022).; 3 Represents 1L SQ-NSCLC patients in above jurisdictions; ~30k patients in US; Sources: Sekine I, et al. Cancer Sci (2020); Uhlig, et al. JAMA Netw Open (2019); Ganti et al. JAMA Oncol. (2021); Decision Resources Group; AZ Epidemiology Data (June 2022). ~600,0001 Lung Cancer Patients in the US, Europe 5*, Japan ~40k Potential Patients to Help Treat2 ~80k Potential Patients to Help Treat3 17 Summit Proprietary Information - Do Not Copy, Photograph or Distribute J.P. Morgan 42nd Annual Healthcare Conference, January 2024

Trial Indication Histology/Population Regimen Phase III NSCLC EGFRm+ 2L+ Advanced or Metastatic Combo ivonescimab + chemo vs. placebo + chemo NSCLC Squamous 1L Metastatic Combo ivonescimab + chemo vs. pembro + chemo Indication Regimen Phase I Phase II Phase III NSCLC: 2L EGFRm+ Randomized: Combo (chemo) vs. chemo NSCLC: 1L PD-L1 TPS>1% Randomized: Monotherapy vs. pembro (PD-1) NSCLC: 1L Squamous Randomized: Combo (chemo) vs. tislelizumab (PD-1) + chemo NSCLC: 1L Squamous Randomized: Combo (chemo) vs. pembro (PD-1) + chemo Advanced Solid Tumors Monotherapy NSCLC Combo (chemo) NSCLC Monotherapy GYN Tumors Monotherapy Ovarian Cancer Combination (PARPi) NSCLC Monotherapy & Combo (chemo) CRC Combo (CD47 + chemo) HCC Monotherapy NSCLC Combo (PD-1 / CTLA-4 bsAb + chemo) HNSCC Combo (CD47) Advanced Solid Tumors** Combo (CD47, CD47 + chemo, chemo) TNBC Comb (chemo, CD47 + chemo) NSCLC Combo (CD73 + chemo) Advanced Solid Tumors Monotherapy ES-SCLC Combo (chemo) Ivonescimab Global Oncology Clinical Trials These ivonescimab clinical trials are being conducted in China and/or Australia and are fully sponsored and managed by Akeso. NSCLC: Non-Small-cell Lung Cancer, EGFRm+: Epidermal Growth Factor Receptor mutant positives, Combo: Combination, Chemo: Chemotherapy, pembro: pembrolizumab, CRC: Colorectal Cancer, HCC: Hepatocellular Carcinoma, HNSCC: Head & Neck Squamous Cell Carcinoma, BTC: Biliary Tract Cancer, TNBC: Triple Negative Breast Cancer, ES-SCLC: Extensive Stage Small Cell Lung Cancer, PD-1: Programmed Cell Death Protein 1, PARPi: poly(ADP-ribose) polymerase inhibitors Ivonescimab is an investigational therapy that is not approved by any regulatory authority. It is currently being investigated in Phase III clinical studies. **Includes Gastric, BTC, Pancreatic, NSCLC Same Subset Patient Population 1,600+ Patients Treated with Ivonescimab 19 Clinical Trials 4 Phase III 13 Phase II 2 Phase I 7 Dedicated Trials Outside NSCLC 18 Summit Proprietary Information - Do Not Copy, Photograph or Distribute J.P. Morgan 42nd Annual Healthcare Conference, January 2024 Same Subset Patient Population

Ivonescimab: Expected 2024 Key Catalysts

Ivonescimab Phase III Trials – Expected 2024 Short-Term Catalysts Ivonescimab is an investigational therapy that is not approved by any regulatory authority. It is currently being investigated in Phase III clinical studies. CDE: Centre for Drug Evaluation *NDA Filing by Akeso with the CDE for Marketing Approval in China, 2023 Head-to-Head vs. Pembrolizumab Same Subset Patient Population 20 Summit Proprietary Information - Do Not Copy, Photograph or Distribute J.P. Morgan 42nd Annual Healthcare Conference, January 2024 AK112-301 CDE Decision Expected* & Topline Data AK112-303 Interim Analysis Randomized Phase III Trial vs. Pembrolizumab Last Patient In H1 H2

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Cover	Jan. 08, 2024
Entity Addresses [Line Items]
Document Type	8-K
Document Period End Date	Jan. 08, 2024
Entity Registrant Name	Summit Therapeutics Inc.
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Trading Symbol	SMMT
Security Exchange Name	NASDAQ
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Entity Central Index Key	0001599298
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