Summit Therapeutics Inc 10-Q for FY2026 Q3
Summit Therapeutics Inc. (SMMT)
10-Q
2026-11-04
For: 2026-09-30
View Original
Added on
November 04, 2026
About this 10-Q
Summit Therapeutics Inc filed this 10-Q on November 4, 2026, covering the quarter ended September 30, 2026 (FY2026 Q3).
Summit Therapeutics’ ivonescimab BLA was accepted in January 2026, with an FDA action date of November 14, 2026. A June 2026 analysis showed an OS hazard ratio of 0.76 (nominal p=0.0151), but FDA requires a statistically significant OS benefit. AI summary
Headline figures
Quarter ended September 30, 2026, as reported in this filing, compared with the same period a year earlier where the filing states it.
- Net loss
- $208.39M
- compared with a net loss of $231.79M a year earlier
- Diluted EPS
- -$0.26
- compared with -$0.31 a year earlier
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, 2026
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
_______________________________
(Exact name of registrant as specified in its charter)
_____________________
(State or other jurisdiction of incorporation or organization) | (I.R.S. Employer Identification No.) | |||||||
(Address of principal executive offices)
(Zip Code)
(Registrant’s telephone number, including area code)
Not Applicable
(Former name or former address and former fiscal year, if changed since last report)
_________________
Securities registered pursuant to Section 12(b) of the Act:
Title of each class | Trading Symbol(s) | Name of each exchange on which registered | ||||||
Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ☒ No ☐
Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes ☒ No ☐
Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer”, “accelerated filer”, “smaller reporting company” and “emerging growth company” in Rule 12b-2 of the Exchange Act.
☒ | Accelerated filer | ☐ | |||||||||
Non-accelerated filer | ☐ | Smaller reporting company | |||||||||
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. ☐
Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes ☐ No ☒
As of October 30, 2026, there were 799,763,918 shares of common stock, par value $0.01 per share, outstanding.
TABLE OF CONTENTS
| Page | ||||||||
| PART I | ||||||||
| Item 1. | ||||||||
| Item 2. | ||||||||
| Item 3. | ||||||||
| Item 4. | ||||||||
| PART II | ||||||||
| Item 1. | ||||||||
| Item 1A. | ||||||||
| Item 2. | ||||||||
| Item 3. | ||||||||
| Item 4. | ||||||||
Item 5. | ||||||||
| Item 6. | ||||||||
CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS
This Quarterly Report on Form 10-Q contains “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), regarding the future financial performance, business prospects and growth of Summit Therapeutics Inc., that involve substantial risks and uncertainties. All statements contained in this Quarterly Report on Form 10-Q, other than statements of historical fact, including statements regarding our strategy, future operations, future financial position, future revenues, projected costs, prospects, plans and objectives of management, are forward-looking statements. The words “anticipate,” “believe,” “estimate,” “expect,” “intend,” “may,” “plan,” “predict,” “project,” “target,” “potential,” “will,” “would,” “could,” “should,” “continue,” and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. The forward-looking statements in this Quarterly Report on Form 10-Q include, among other things, statements about:
•the ability to develop a successful product candidate under the License Agreement (as defined in Part I, Item 1 Financial Statements, Note 1 Organization);
•our ability to raise sufficient additional funds to make payments under the License Agreement, and fund ongoing operations and capital needs;
•the timing of and the ability to effectively execute clinical development of ivonescimab;
•the timing, costs, conduct and outcomes of clinical trials for any product candidates, including ivonescimab;
•our plans with respect to possible future collaborations and partnering arrangements;
•the potential benefits of possible future acquisitions or investments in other businesses, products or technologies;
•our plans to pursue research and development of other future product candidates;
•the effects of AstraZeneca’s (as defined below) ownership and contractual rights on us and our stockholders;
•our reliance on third parties for the supply of third-party products and other contributions to certain clinical trials involving the combination of ivonescimab with third-party products;
•our estimates regarding the potential market opportunity and patient population for commercializing our product candidates, if approved for commercial use;
•our sales, marketing and distribution capabilities and strategy;
•our ability to establish and maintain arrangements with third parties, such as contract research organizations, contract manufacturing organizations, suppliers and distributors;
•the costs and timing of preparing, filing and prosecuting patent applications, maintaining and protecting our intellectual property rights and defending against any intellectual property-related claims;
•our estimates regarding expenses, future revenues, capital requirements and needs for additional financing;
•the impact of government laws and regulations in the United States and in foreign countries;
•the timing and likelihood of regulatory filings and approvals for our product candidates;
•whether regulatory authorities determine that additional trials or data are necessary in order to accept a new drug application for review and/or approval;
•our competitive position;
•our ability to attract and retain key scientific or management personnel;
•the impact of public health epidemics, such as the novel coronavirus pandemic, natural disasters or geopolitical instability, the response to such events and the potential effects of such events on our business, financial results, supply chain and market;
•the outcome of pending, threatened, and future legal proceedings;
•our expectations regarding the anticipated timeline and our planned use of our cash, cash equivalents and short-term investments, future financial performance and our ability to continue as a going concern;
•estimates regarding stock-based compensation;
•general economic conditions, including economic slowdowns or other adverse economic conditions, such as periods of increased or prolonged inflation; and
•other risks and uncertainties, including those described under the heading “Risk Factors” included in this Quarterly Report on Form 10-Q and in our most recent Annual Report on Form 10-K for the year ended December 31, 2025, filed with the U.S. Securities and Exchange Commission (“SEC”) on February 23, 2026 (the “Annual Report”).
1
We may not actually achieve the plans, intentions or expectations disclosed in our forward-looking statements, and you should not place undue reliance on our forward-looking statements. Actual results or events could differ materially from the plans, intentions and expectations disclosed in the forward-looking statements we make. We have included important factors in the cautionary statements included in this Quarterly Report on Form 10-Q, particularly in the “Risk Factors” and “Management's Discussion and Analysis of Financial Condition and Results of Operations” sections in this Quarterly Report on Form 10-Q, that we believe could cause actual results or events to differ materially from the forward-looking statements that we make. Our forward-looking statements do not reflect the potential impact of any future acquisitions, mergers, dispositions, joint ventures or investments we may make.
You should read this Quarterly Report on Form 10-Q and the documents that we have filed as exhibits to this Quarterly Report on Form 10-Q completely and with the understanding that our actual future results may be materially different from what we expect. We do not assume any obligation to update any forward-looking statements.
2
PART I - FINANCIAL INFORMATION
Item 1. Financial Statements.
Summit Therapeutics Inc.
Condensed Consolidated Balance Sheets
(in thousands, except share and per share data)
(Unaudited)
| September 30, 2026 | December 31, 2025 | |||||||||||||
| Assets | ||||||||||||||
| Current assets: | ||||||||||||||
| Cash and cash equivalents | $ | $ | ||||||||||||
| Restricted cash | ||||||||||||||
| Short-term investments | ||||||||||||||
| Prepaid expenses and other current assets | ||||||||||||||
| Total current assets | ||||||||||||||
| Non-current assets: | ||||||||||||||
| Property and equipment, net | ||||||||||||||
| Operating lease right-of-use assets | ||||||||||||||
| Goodwill | ||||||||||||||
| Other assets | ||||||||||||||
| Total assets | $ | $ | ||||||||||||
| Liabilities and stockholders' equity | ||||||||||||||
| Current liabilities: | ||||||||||||||
| Accounts payable | $ | $ | ||||||||||||
| Accrued liabilities | ||||||||||||||
| Accrued compensation | ||||||||||||||
| Operating lease liabilities, current portion | ||||||||||||||
| Other current liabilities | ||||||||||||||
| Total current liabilities | ||||||||||||||
| Non-current liabilities: | ||||||||||||||
| Operating lease liabilities, net of current portion | ||||||||||||||
| Other non-current liabilities | ||||||||||||||
| Total liabilities | ||||||||||||||
Commitments and contingencies (Note 13) | ||||||||||||||
| Stockholders' equity: | ||||||||||||||
Preferred stock, $ | ||||||||||||||
Common stock, $ | ||||||||||||||
| Additional paid-in capital | ||||||||||||||
| Accumulated other comprehensive loss | ( | ( | ||||||||||||
| Accumulated deficit | ( | ( | ||||||||||||
| Total stockholders' equity | ||||||||||||||
| Total liabilities and stockholders' equity | $ | $ | ||||||||||||
The accompanying notes are an integral part of the unaudited condensed consolidated financial statements.
3
Summit Therapeutics Inc.
Condensed Consolidated Statements of Operations and Comprehensive Loss
(in thousands, except share and per share data)
(Unaudited)
| Three Months Ended September 30, | Nine Months Ended September 30, | |||||||||||||||||||||||||
| 2026 | 2025 | 2026 | 2025 | |||||||||||||||||||||||
| Operating expenses: | ||||||||||||||||||||||||||
Research and development (1) | $ | $ | $ | $ | ||||||||||||||||||||||
| General and administrative | ||||||||||||||||||||||||||
| Total operating expenses | ||||||||||||||||||||||||||
| Other income, net | ||||||||||||||||||||||||||
| Net loss | $ | ( | $ | ( | $ | ( | $ | ( | ||||||||||||||||||
| Net loss per share: | ||||||||||||||||||||||||||
| Basic and diluted | $ | ( | $ | ( | $ | ( | $ | ( | ||||||||||||||||||
Weighted average common shares outstanding: | ||||||||||||||||||||||||||
| Basic and diluted | ||||||||||||||||||||||||||
| Other comprehensive income (loss): | ||||||||||||||||||||||||||
| Foreign currency translation adjustments | ( | |||||||||||||||||||||||||
Unrealized loss on short-term investments | ( | ( | ( | |||||||||||||||||||||||
| Comprehensive loss | $ | ( | $ | ( | $ | ( | $ | ( | ||||||||||||||||||
(1) Refer to Note 12 – Related Party Transactions for expenses incurred.
The accompanying notes are an integral part of the unaudited condensed consolidated financial statements.
4
Summit Therapeutics Inc.
Condensed Consolidated Statements of Stockholders' Equity
(in thousands, except share data)
(Unaudited)
| Common Stock | Additional Paid-In Capital | Accumulated Other Comprehensive Loss | Accumulated Deficit | Total Stockholders' Equity | ||||||||||||||||||||||||||||||||||
| Shares | Amount | |||||||||||||||||||||||||||||||||||||
| Balance at December 31, 2025 | $ | $ | $ | ( | $ | ( | $ | |||||||||||||||||||||||||||||||
| Issuance of common stock under stock purchase plans and exercise of stock options | — | — | ||||||||||||||||||||||||||||||||||||
| Stock-based compensation | — | — | — | — | ||||||||||||||||||||||||||||||||||
| Net other comprehensive loss | — | — | — | ( | — | ( | ||||||||||||||||||||||||||||||||
| Net loss | — | — | — | — | ( | ( | ||||||||||||||||||||||||||||||||
| Balance at March 31, 2026 | $ | $ | $ | ( | $ | ( | $ | |||||||||||||||||||||||||||||||
| Issuance of common stock upon exercise of stock options | — | — | ||||||||||||||||||||||||||||||||||||
Proceeds from at-the-market offering, net of commissions of $ | — | — | ||||||||||||||||||||||||||||||||||||
| Stock-based compensation | — | — | — | |||||||||||||||||||||||||||||||||||
| Net other comprehensive loss | — | — | — | ( | — | ( | ||||||||||||||||||||||||||||||||
| Net loss | — | — | — | — | ( | ( | ||||||||||||||||||||||||||||||||
| Balance at June 30, 2026 | $ | $ | $ | ( | $ | ( | $ | |||||||||||||||||||||||||||||||
| Issuance of common stock under stock purchase plans and exercise of stock options | — | — | ||||||||||||||||||||||||||||||||||||
Proceeds from at-the-market offering, net of commissions of $ | — | — | ||||||||||||||||||||||||||||||||||||
| Stock-based compensation | — | — | — | — | ||||||||||||||||||||||||||||||||||
| Net other comprehensive loss | — | — | — | ( | — | ( | ||||||||||||||||||||||||||||||||
| Net loss | — | — | — | — | ( | ( | ||||||||||||||||||||||||||||||||
| Balance at September 30, 2026 | $ | $ | $ | ( | $ | ( | $ | |||||||||||||||||||||||||||||||
5
Summit Therapeutics Inc.
Condensed Consolidated Statements of Stockholders' Equity
(in thousands, except share data)
(Unaudited)
| Common Stock | Additional Paid-In Capital | Accumulated Other Comprehensive Loss | Accumulated Deficit | Total Stockholders' Equity | ||||||||||||||||||||||||||||||||||
| Shares | Amount | |||||||||||||||||||||||||||||||||||||
| Balance at December 31, 2024 | $ | $ | $ | ( | $ | ( | $ | |||||||||||||||||||||||||||||||
Issuance of common stock under stock purchase plans and exercise of stock options and warrants (2) | — | — | ||||||||||||||||||||||||||||||||||||
| Stock-based compensation | — | — | — | — | ||||||||||||||||||||||||||||||||||
| Net other comprehensive loss | — | — | — | ( | ( | |||||||||||||||||||||||||||||||||
| Net loss | — | — | — | — | ( | ( | ||||||||||||||||||||||||||||||||
| Balance at March 31, 2025 | $ | $ | $ | ( | $ | ( | $ | |||||||||||||||||||||||||||||||
Issuance of common stock upon exercise of stock options and warrants (2) | — | — | ||||||||||||||||||||||||||||||||||||
| Stock-based compensation | — | — | — | — | ||||||||||||||||||||||||||||||||||
| Net other comprehensive loss | — | — | — | ( | — | ( | ||||||||||||||||||||||||||||||||
| Net loss | — | — | — | — | ( | ( | ||||||||||||||||||||||||||||||||
| Balance at June 30, 2025 | $ | $ | $ | ( | $ | ( | $ | |||||||||||||||||||||||||||||||
| Issuance of common stock under stock purchase plans and exercise of stock options | — | — | ||||||||||||||||||||||||||||||||||||
Proceeds from at-the-market offering, net of commissions and offering costs of $ | — | — | ||||||||||||||||||||||||||||||||||||
| Stock-based compensation | — | — | — | — | ||||||||||||||||||||||||||||||||||
| Net other comprehensive gain | — | — | — | — | ||||||||||||||||||||||||||||||||||
| Net loss | — | — | — | — | ( | ( | ||||||||||||||||||||||||||||||||
| Balance at September 30, 2025 | $ | $ | $ | ( | $ | ( | $ | |||||||||||||||||||||||||||||||
(2) Refer to Note 12 – Related Party Transactions .
The accompanying notes are an integral part of the unaudited condensed consolidated financial statements.
6
Summit Therapeutics Inc.
Condensed Consolidated Statements of Cash Flows
(in thousands)
(Unaudited)
| Nine Months Ended September 30, | |||||||||||
| 2026 | 2025 | ||||||||||
| Cash flows from operating activities: | |||||||||||
Net loss | $ | ( | $ | ( | |||||||
Adjustments to reconcile net loss to net cash used in operating activities: | |||||||||||
| Amortization of discount on short-term investments | ( | ( | |||||||||
Unrealized foreign exchange loss (gain) | ( | ||||||||||
Depreciation | |||||||||||
Stock-based compensation | |||||||||||
Change in operating assets and liabilities: | |||||||||||
Prepaid expenses and other current assets | ( | ||||||||||
Other assets | ( | ||||||||||
Accounts payable | |||||||||||
Accrued liabilities | |||||||||||
| Accrued compensation | ( | ||||||||||
| Other current liabilities | ( | ||||||||||
Other non-current liabilities | ( | ||||||||||
| Other long-term assets | ( | ||||||||||
Operating lease right-of-use assets and lease liabilities, net | ( | ||||||||||
| Net cash used in operating activities | ( | ( | |||||||||
| Cash flows from investing activities: | |||||||||||
| Maturities and sales of short-term investments | |||||||||||
| Purchase of short-term investments | ( | ||||||||||
Purchases of property and equipment | ( | ( | |||||||||
| Net cash provided by investing activities | |||||||||||
| Cash flows from financing activities: | |||||||||||
Proceeds from the issuance of common stock under at-the-market offering, net of commissions (3) | |||||||||||
Proceeds received related to employee stock purchase plan and exercise of stock options | |||||||||||
Proceeds from exercise of warrants (3) | |||||||||||
| Net cash provided by financing activities | |||||||||||
| Effect of exchange rate changes on cash | ( | ||||||||||
| (Decrease) increase in cash, cash equivalents and restricted cash | ( | ||||||||||
| Cash, cash equivalents and restricted cash at beginning of period | |||||||||||
| Cash, cash equivalents and restricted cash at end of period | $ | $ | |||||||||
| Reconciliation of cash, cash equivalents and restricted cash: | |||||||||||
| Cash and cash equivalents | $ | $ | |||||||||
| Restricted cash | |||||||||||
Total cash, cash equivalents and restricted cash | $ | $ | |||||||||
| Supplemental Disclosure of Non-Cash Investing and Financing Activities: | |||||||||||
| Offering costs included in accounts payable and accrued expenses | $ | $ | |||||||||
| Leased assets obtained in exchange for operating lease liabilities | $ | $ | |||||||||
Unpaid amounts related to property and equipment, net | $ | $ | |||||||||
(3) Refer to Note 12 – Related Party Transactions .
The accompanying notes are an integral part of the unaudited condensed consolidated financial statements.
7
Summit Therapeutics Inc.
Notes to Unaudited Condensed Consolidated Financial Statements
(in thousands, except share and per share data)
1. Organization
Summit Therapeutics Inc. (“we”, “Summit” or the “Company”) is a biopharmaceutical company focused on the discovery, development, and commercialization of patient-, physician-, caregiver- and societal-friendly medicinal therapies intended to improve quality of life, increase potential duration of life, and resolve serious unmet medical needs. The Company’s pipeline product candidate is designed with the goal to become patient-friendly, new-era standard-of-care medicine, in the therapeutic area of oncology.
The Company’s current lead development candidate is ivonescimab, a novel, potential first-in-class bispecific antibody intending to combine the effects of immunotherapy via a blockade of PD-1 with the anti-angiogenesis effects of an anti-VEGF compound into a single molecule. On December 5, 2022, the Company entered into the License Agreement with Akeso, Inc. and its affiliates (collectively, “Akeso”) pursuant to which the Company has in-licensed intellectual property rights related to ivonescimab (as amended, the “License Agreement”), as further described in Note 4. Through the License Agreement, the Company obtained the rights to develop and commercialize ivonescimab in the United States, Canada, Europe, and Japan. The License Agreement and transaction closed in January 2023 following customary waiting periods. On June 3, 2024, the Company entered into an amendment to the License Agreement (the “Second Amendment”) with Akeso to expand its territories covered under the License Agreement to also include Latin America, including Mexico and all countries in Central America and South America, the Middle East and Africa (collectively, and as expanded, the “Licensed Territory”). The Company’s operations are focused on the development of ivonescimab and other future activities, as the Company determines.
Basis of Presentation
Use of Estimates
The preparation of these unaudited condensed consolidated financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the unaudited condensed consolidated financial statements and the reported amounts of income and expenses during the reporting period. On an on-going basis, management evaluates its estimates and judgments, including those related to accrued research and development expenses, stock-based compensation, and income taxes. Management bases its estimates and judgments on historical experience and on various other factors that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results may differ from these estimates under different assumptions or conditions.
Liquidity and Capital Resources
During the three and nine months ended September 30, 2026, the Company incurred a net loss of $208,385 and $613,509 , respectively, and cash used in operating activities for the nine months ended September 30, 2026 was $423,229 . As of
8
Summit Therapeutics Inc.
Notes to Unaudited Condensed Consolidated Financial Statements
(in thousands, except share and per share data)
September 30, 2026, the Company had an accumulated deficit of $2,907,668 , cash and cash equivalents of $150,811 and short-term investments of $478,976 . The Company expects to continue to generate operating losses for the foreseeable future.
Subsequent to the quarter ended September 30, 2026, the Company received gross proceeds of $2,000,000 from AstraZeneca Holdings B.V, a subsidiary of AstraZeneca plc (together with its subsidiaries, “AstraZeneca”) in connection with the closing of the AstraZeneca Equity Investment (as defined below). For additional detail on the AstraZeneca Equity Investment, refer to Note 10 AstraZeneca Equity Investment. With the AstraZeneca Equity Investment, the Company has evaluated and concluded that its cash, cash equivalents and short-term investments provide sufficient cash to fund its operating cash needs for at least the next 12 months from the date of issuance of these unaudited condensed consolidated financial statements.
Until the Company can generate substantial revenue and achieve profitability, the Company will need to raise additional capital to fund its ongoing operations and capital needs. The Company continues to evaluate options to further finance its operating cash needs for its product candidates through a combination of some, or all, of the following: equity and debt offerings, collaborations, strategic alliances, grants and clinical trial support from government entities, philanthropic, non-government and not-for-profit organizations, and marketing, distribution or licensing arrangements. There is no assurance, however, that additional financing will be available when needed or that management of the Company will be able to obtain financing on terms acceptable to the Company. If the Company is unable to obtain funding when required in the future, the Company could be required to delay, reduce, or eliminate research and development programs, product portfolio expansion, or future commercialization efforts, which could adversely affect its business prospects.
2. Summary of Significant Accounting Policies and Recent Accounting Pronouncements
Significant Accounting Policies
There have been no significant changes to the Company’s significant accounting policies used in the preparation of these unaudited condensed consolidated financial statements for the nine months ended September 30, 2026 as compared with those discussed in Note 2 to the consolidated financial statements in the Company’s Annual Report.
Recently Issued Accounting Pronouncements
In November 2024, the FASB issued ASU 2024-03, Disaggregation of Income Statement Expenses (“ASU 2024-03”) which requires disclosures about specific types of expenses included in the expense captions presented on the face of the income statement as well as disclosures. The guidance is to be applied prospectively, with the option for retrospective application and is effective for public business entities for fiscal years beginning after December 15, 2026, and interim periods beginning after December 15, 2027. Early adoption is permitted. The Company is currently evaluating the impact of the adoption of this standard on the Company’s consolidated financial statements and related disclosures.
In December 2025, the FASB issued ASU 2025-11, “Narrow-Scope Improvements”, which is intended to improve the navigability of the guidance in ASC 270 and clarify when the guidance is applicable. ASU 2025-11 is effective for interim reporting periods within annual reporting periods beginning after December 15, 2027. Early adoption is permitted. The Company is currently evaluating the impact of the adoption of this standard on the Company’s consolidated financial statements and related disclosures.
Other recent authoritative guidance issued by the FASB (including technical corrections to the FASB ASC), the American Institute of Certified Public Accountants, and the SEC did not or are not expected to have a material impact on the Company’s consolidated financial statements and related disclosures.
3. Segment Reporting
The Company’s chief operating decision makers (the “CODM function”), which are the Company’s Co-Chief Executive Officers, Mr. Duggan and Dr. Zanganeh, and Chief Operating Officer and Chief Financial Officer, Mr. Soni, utilize consolidated net loss that is reported on the unaudited condensed consolidated statement of operations and comprehensive loss to make decisions about allocating resources and assessing performance for the entire Company. The CODM function
9
Summit Therapeutics Inc.
Notes to Unaudited Condensed Consolidated Financial Statements
(in thousands, except share and per share data)
approves key operating and strategic decisions, including key decisions in clinical development and clinical operating activities, entering into significant contracts, such as revenue contracts and collaboration agreements and approves the Company’s consolidated operating budget. The CODM function views the Company’s operations and manages its business on a consolidated basis and as a single reportable operating segment. The CODM function is regularly provided with the following significant segment expenses:
| Three Months Ended September 30, | Nine Months Ended September 30, | |||||||||||||||||||||||||
| 2026 | 2025 | 2026 | 2025 | |||||||||||||||||||||||
| Oncology clinical trial related costs | $ | $ | $ | $ | ||||||||||||||||||||||
| Compensation related costs, excluding stock-based compensation | ||||||||||||||||||||||||||
| Stock-based compensation | ||||||||||||||||||||||||||
Other expenses (1) | ||||||||||||||||||||||||||
| Total segment expenses | ||||||||||||||||||||||||||
| Other income, net | ||||||||||||||||||||||||||
| Net loss | $ | ( | $ | ( | $ | ( | $ | ( | ||||||||||||||||||
(1) Other expenses include general and administrative expenses excluding compensation and stock-based compensation.
As of September 30, 2026 and December 31, 2025, substantially all of the Company’s long-lived assets are located in the United States.
4. Akeso License and Collaboration Agreement
On December 5, 2022, the Company entered into the License Agreement with Akeso pursuant to which the Company is in-licensing its bispecific antibody, ivonescimab. The License Agreement and transaction closed in January 2023 following customary waiting periods.
Ivonescimab, known as AK112 in China and Australia, and also as SMT112 in the Summit Licensed Territory, is a novel, potential first-in-class bispecific antibody intending to combine the effect of immunotherapy via a blockade of PD-1 with the anti-angiogenesis effects of an anti-VEGF into a single molecule. Ivonescimab was invented to bring two well-established oncology targeted mechanisms together. Ivonescimab is currently in clinical development and, pursuant to the terms of the License Agreement, Summit will design and conduct the clinical trial activities to support regulatory filings in the Licensed Territory that Summit will submit.
Pursuant to the terms of the License Agreement, Summit will have final decision-making authority with respect to clinical development strategy and execution in the Licensed Territory. For co-joined studies in which both Summit and Akeso participate, mutual agreement is required for material decisions; Summit retains the exclusive decision making with respect to participating in, and continuing its participation in, co-joined studies in the Licensed Territory. Pursuant to the terms of the License Agreement, Summit will have final decision-making authority with respect to commercial strategy, pricing and reimbursement and other commercialization matters in the Licensed Territory. In connection with the License Agreement, the Company agreed to purchase a certain portion of drug substance and/or drug product for clinical and commercial supply and to enter into a supply agreement with Akeso. Summit is not assuming any liabilities (including contingent liabilities), acquiring any physical assets or trade names, or hiring or acquiring any employees from Akeso in connection with the License Agreement. Through the License Agreement, the Company obtained the rights to develop and commercialize ivonescimab in the United States, Canada, Europe, and Japan.
In exchange for the rights obtained, the Company made an upfront payment of $500,000 to Akeso, of which $274,900 was paid in cash and, pursuant to the License Agreement and Issuance Agreement, Akeso elected to receive 10,000,000 shares of the Company’s common stock, par value $0.01 per share (“common stock”) in lieu of $25,100 in cash. The remaining $200,000 amount of the upfront payment was paid on March 6, 2023.
10
Summit Therapeutics Inc.
Notes to Unaudited Condensed Consolidated Financial Statements
(in thousands, except share and per share data)
Effective June 3, 2024, the Company and Akeso entered into the Second Amendment to the License Agreement to expand the Company’s territories covered under the License Agreement to include the Latin America, Middle East and Africa regions. Pursuant to the Second Amendment, the Company paid an upfront payment to Akeso of $15,000 in the third quarter of 2024. Akeso will also be eligible to receive up to an additional $55,000 upon the achievement of certain commercial milestones. Except as specifically modified by the Second Amendment, the terms and conditions of the License Agreement remain in full force and effect.
The Company has accounted for the License Agreement and Second Amendment to acquire the rights to develop and commercialize ivonescimab as the acquisition of an asset. All of the consideration relates to ivonescimab and technological feasibility of the asset has not yet been established since ivonescimab is in clinical development. As such, the Company has expensed the consideration as acquired in-process research and development upon closing of the transaction in the unaudited condensed consolidated statement of operations and comprehensive loss. There was no acquired in-process research and development expense for the three and nine months ended September 30, 2026 and 2025, respectively. In addition to the payments already made to Akeso, under the License Agreement and Second Amendment, there are additional potential milestone payments of up to $4,555,000 , as Akeso will be eligible to receive regulatory milestones of up to $1,050,000 and commercial milestones of up to $3,505,000 . In addition, Akeso will be eligible to receive low double-digit royalties on net sales.
5. Other Income, Net
The following table sets forth the components of other income, net:
| Three Months Ended September 30, | Nine Months Ended September 30, | |||||||||||||||||||||||||||||||||||||
| 2026 | 2025 | 2026 | 2025 | |||||||||||||||||||||||||||||||||||
| Foreign currency loss | $ | ( | $ | ( | $ | ( | $ | ( | ||||||||||||||||||||||||||||||
Investment income (1) | ||||||||||||||||||||||||||||||||||||||
Other (2) | ( | |||||||||||||||||||||||||||||||||||||
Total | $ | $ | $ | $ | ||||||||||||||||||||||||||||||||||
(1) Investment income relates to the Company’s money market funds, certificate of deposit and U.S. government treasury bills. Refer to Note 7 for details.
(2) In June 2026, the Company entered into an asset purchase agreement (the “APA”) with a third party. Pursuant to the APA, the Company sold the asset relating to the pharmaceutical compound known as ridinilazole. In consideration for such assignment of rights, the third party has made an upfront non-refundable payment to the Company of $500 . Additionally, the third party has also agreed to make additional payments totaling $1,500 that are contingent upon the achievement of certain regulatory milestones, sales-based milestone payments of up to $103,000 , as well as quarterly royalty payments that are based on a single digit percentage of net sales for certain products covered by the assigned and transferred patent rights. The Company did not have any amounts capitalized related to the underlying portfolio of patents, nor was any write-down of assets recorded upon executing the APA. The Company received the payment of $500 from the third party in June 2026 and recognized the $500 within other income, net on the condensed consolidated statements of operations and comprehensive loss for the nine months ended September 30, 2026. The Company does not have any ongoing obligations associated with the APA. As of September 30, 2026, the Company is unable to estimate the timing or likelihood of achieving the regulatory milestone payments, sales-based milestone payments, and the quarterly royalty payments.
11
Summit Therapeutics Inc.
Notes to Unaudited Condensed Consolidated Financial Statements
(in thousands, except share and per share data)
6. Net Loss per Share
The following table sets forth the computation of basic and diluted net loss per share:
| Three Months Ended September 30, | Nine Months Ended September 30, | |||||||||||||||||||||||||
| 2026 | 2025 | 2026 | 2025 | |||||||||||||||||||||||
| Net loss | $ | ( | $ | ( | $ | ( | $ | ( | ||||||||||||||||||
| Basic and diluted weighted average number of shares of common stock outstanding | ||||||||||||||||||||||||||
| Basic net loss per share | $ | ( | $ | ( | $ | ( | $ | ( | ||||||||||||||||||
| Diluted net loss per share | $ | ( | $ | ( | $ | ( | $ | ( | ||||||||||||||||||
Basic net loss per share is computed by dividing the net loss by the weighted-average number of common shares outstanding for the period. Diluted net loss per share is computed by dividing the diluted net loss by the weighted-average number of common shares outstanding for the period, including potentially dilutive common shares. Since the Company was in a loss position for all periods presented, basic net loss per share is the same as diluted net loss per share for all periods, as the inclusion of all potential common share equivalents outstanding would have been anti-dilutive.
The following potentially dilutive securities were excluded from the computation of the diluted net loss per share of common stock for the periods presented because their effect would have been anti-dilutive:
| September 30, | ||||||||||||||
| 2026 | 2025 | |||||||||||||
| Options to purchase common stock | ||||||||||||||
Restricted stock units | ||||||||||||||
| Shares expected to be purchased under employee stock purchase plan | ||||||||||||||
| Total | ||||||||||||||
Stock options that are outstanding and contain improbable vesting criteria are excluded from the presentation of common stock equivalents outstanding in the table above.
12
Summit Therapeutics Inc.
Notes to Unaudited Condensed Consolidated Financial Statements
(in thousands, except share and per share data)
7. Fair Value Measurements and Short-Term Investments
The following tables set forth the Company’s fair value hierarchy for its assets and liabilities that are measured at fair value on a recurring basis as of September 30, 2026 and December 31, 2025:
| September 30, 2026 | ||||||||||||||||||||
Fair Value Hierarchy Level | Amortized Cost | Unrealized Gain | Unrealized (Loss) | Credit (Loss) | Fair Value | |||||||||||||||
| Financial assets included within cash and cash equivalents: | ||||||||||||||||||||
| Money market funds | Level 1 | $ | $ | $ | $ | $ | ||||||||||||||
| Financial assets included within short-term investments: | ||||||||||||||||||||
Certificate of deposit | Level 2 | |||||||||||||||||||
| U.S. Government treasury bills | Level 2 | ( | ||||||||||||||||||
| Total | $ | $ | $ | ( | $ | $ | ||||||||||||||
| December 31, 2025 | ||||||||||||||||||||
Fair Value Hierarchy Level | Amortized Cost | Unrealized Gain | Unrealized (Loss) | Credit (Loss) | Fair Value | |||||||||||||||
| Financial assets included within cash and cash equivalents: | ||||||||||||||||||||
| Money market funds | Level 1 | $ | $ | $ | $ | $ | ||||||||||||||
U.S. Government treasury bills | Level 2 | |||||||||||||||||||
| Financial assets included within short-term investments: | ||||||||||||||||||||
Certificate of deposit | Level 2 | |||||||||||||||||||
| U.S. Government treasury bills | Level 2 | |||||||||||||||||||
| Total | $ | $ | $ | $ | $ | |||||||||||||||
The tables above do not include cash at September 30, 2026 and December 31, 2025 of $7,555 and $16,366 , respectively.
The Company believes that the carrying amounts of prepaid expenses and other current assets, accounts payable, and accrued liabilities approximate their fair values due to the short-term nature of those instruments.
Realized gain (loss) on short-term investments for the three and nine months ended September 30, 2026 and 2025 were de minimis, respectively.
8. Research and Development Prepaid Expenses and Accrued Liabilities
Included within prepaid expenses and other current assets at September 30, 2026 and December 31, 2025 is $26,223 and $3,996 , respectively, of prepayments relating to research and development expenditures. Included within accrued liabilities at September 30, 2026 and December 31, 2025 is $53,210 and $31,498 , respectively, relating to research and development expenditures.
These amounts are determined based on the estimated costs to complete each study or activity related to the ongoing clinical trials for ivonescimab, the estimation of the current stage of completion and the invoices received, as well as predetermined
13
Summit Therapeutics Inc.
Notes to Unaudited Condensed Consolidated Financial Statements
(in thousands, except share and per share data)
milestones which are not reflective of the current stage of development for prepaid expenses. However, accrued liabilities increase as the activities progress. The key sensitivity is the estimated current stage of completion of each study or activity, which is based on information received from the supplier and the Company’s operational knowledge of the work completed under those contracts.
9. Stockholders' Equity
Preferred Stock
As of September 30, 2026 and December 31, 2025, the Company had 20,000,000 0.01 no
Common Stock
As of September 30, 2026 and December 31, 2025, the Company had authorized 1,000,000,000
October 2025 Private Investment in Public Equity (PIPE)
On October 21, 2025, the Company entered into securities purchase agreements (the “October 2025 Purchase Agreements”) with multiple biotech institutional investors and individual accredited investors, for the sale by the Company in a private placement for an aggregate of 26,682,846 shares of the Company’s common stock, par value $0.01 per share of common stock, at purchase price of $18.74 per share, which was the closing price of the common stock on October 21, 2025, for aggregate gross proceeds to the Company of approximately $500,037 , with immaterial offering costs. The private placement transaction was completed in October 2025.
All of the Company's Section 16 officers participated in the capital raise. The Company’s Co-CEO, Executive Chairman and majority stockholder, its Co-CEO and the President and member of the Board, its COO, CFO, and member of the Board, its CAO, and certain non-executive employees and other related persons purchased an aggregate of 14,514,402 shares of common stock for gross proceeds of approximately $272,000 . Additionally, Akeso purchased 533,617 shares of common stock for gross proceeds of approximately $10,000 . The remaining $218,037 was raised with multiple leading biotech institutional investors.
The October 2025 Purchase Agreements contain customary representations, warranties and covenants by the Company, customary indemnification obligations of the Company, including for liabilities under the Securities Act, as amended (the “Securities Act”), other obligations of the parties and termination provisions. The representations, warranties and covenants contained in the October 2025 Purchase Agreements were made only for purposes of the October 2025 Purchase Agreements and as of specific dates, were solely for the benefit of the parties to such agreements and were subject to limitations agreed upon by the contracting parties.
On October 21, 2025, in connection with the October 2025 Purchase Agreements, the Company entered into Registration Rights Agreements with the Investors (the “October 2025 Registration Rights Agreements”). The October 2025 Registration Rights Agreements provide, among other things, that the Company will as soon as reasonably practicable, and in any event by no later than December 19, 2025, file with the SEC a registration statement registering the resale of the shares. The Company filed the registration statement on October 29, 2025, which was automatically effective upon filing.
At-the-Market Offering (ATM Offering)
On May 13, 2024, the Company entered into an at-the-market (“ATM”) sales agreement (the “Original Distribution Agreement”) pursuant to which the Company may, subject to the terms and conditions set forth in the agreement offer and sell, from time to time, through or to the agents, acting as agents or principal, shares of the Company’s common stock, par value $0.01 , having an aggregate offering price of up to $90,000 . On August 11, 2025, the Company entered into an amendment (the “Amendment”) to the Original Distribution Agreement (as amended, the “Distribution Agreement”), which among other things, increased the aggregate offering price of common stock that the Company may offer and sell from time
14
Summit Therapeutics Inc.
Notes to Unaudited Condensed Consolidated Financial Statements
(in thousands, except share and per share data)
to time through the sales agent under the Distribution Agreement by an additional $360,000 . As of September 30, 2026, the company fully utilized the proceeds available under the Distribution Agreement.
On July 23, 2026, the Company entered into an ATM sales agreement (the “Second Distribution Agreement”), pursuant to which the Company may offer and sell, from time to time, through the sales agent, shares of the Company's common stock, par value $0.01 per share, having an aggregate offering price of up to $380,000 .
From the date of the Original Distribution Agreement through September 30, 2026, the Company sold 29,778,022 shares of common stock under the ATM at a weighted-average price of $15.98 per share, for gross proceeds of $475,708 , with commissions and fees of approximately $7,906 . The remaining gross proceeds available under the Second Distribution Agreement as of September 30, 2026 were approximately $354,292 . The Company plans to use the net proceeds from this offering for working capital and general corporate purposes.
Warrants
As of September 30, 2026 and December 31, 2025, the Company had no 4,629,988 with a weighted average exercise price of $1.58 were exercised. During the three months ended September 30, 2025, no warrants were exercised.
10. AstraZeneca Equity Investment
On September 28, 2026, the Company entered into a securities purchase agreement with AstraZeneca (the “AstraZeneca SPA”) for the issuance and sale by the Company of approximately 108,955 shares of the Company’s newly designated Class A Convertible Preferred Stock, par value $0.01 (the “Class A Preferred Stock”), at a price of $18,356.14 per share (the “AstraZeneca Equity Investment”). Each share of Class A Preferred Stock, upon issuance, is convertible into 1,000 shares of common stock, for a total of 108,955,369 shares of common stock at a conversion price of $18.3561 per share.
The conversion of the Class A Preferred Stock is subject to the expiration and termination of the applicable waiting period of the Hart‑Scott‑Rodino Antitrust Improvements Act of 1976 (“HSR”) and the Company obtaining shareholder approval to amend its certificate of incorporation to increase the number of authorized shares of common stock by 1,000,000,000 (the “Charter Amendment Proposal”). The stockholders of the Company approved the Charter Amendment Proposal on November 4, 2026. The Class A Preferred Stock and the common stock issuable on conversion are subject to a one-year lock-up period after closing.
On October 5, 2026, the Company completed the closing of the AstraZeneca Equity Investment. In connection with the closing, the Company issued the Class A Preferred Stock to AstraZeneca and received gross proceeds of $2,000,000 before issuance costs. In connection with the closing of the AstraZeneca Equity Investment, the Company entered into a registration rights agreement with AstraZeneca (the “AstraZeneca Registration Rights Agreement”). The AstraZeneca Registration Rights Agreement provides, among other things, that the Company will as soon as reasonably practicable, and in any event by no later than 60 days after closing of the AstraZeneca SPA, file with the Securities and Exchange Commission a registration statement registering the resale of the shares of common stock issuable upon the conversion of the Class A Preferred Stock.
11. Stock-Based Compensation
2020 Stock Award Plan
The Company currently grants stock options and restricted stock units to employees and directors under the 2020 Stock Incentive Plan (the “2020 Plan”) and formerly, the Company granted stock options under the 2016 Long Term Incentive Plan. The 2020 Plan is administered by the Compensation Committee of the Company’s Board of Directors. The 2020 Plan is intended to attract and retain employees and directors and provide an incentive for these individuals to assist the Company to achieve long-range performance goals and to enable these individuals to participate in the long-term growth of the Company.
15
Summit Therapeutics Inc.
Notes to Unaudited Condensed Consolidated Financial Statements
(in thousands, except share and per share data)
Based on the provisions of the 2020 Plan, the number of shares of common stock available for issuance under the 2020 Plan increased by 6,400,000 shares on January 1, 2026. On September 18, 2025, the Board approved an increase of 8,000,000 shares of common stock available for issuance under the 2020 Plan (the “Incremental Pool”), which was approved by the majority of the shares voting at the Company’s Annual Meeting of Stockholders on June 10, 2026. As of September 30, 2026, there were 12,573,799 shares available for grant under the 2020 Plan.
On May 3, 2024, the Board adopted the 2024 Inducement Pool (the “Inducement Pool”), which mirrors the terms of the 2020 Plan, with a total of 2,000,000 shares of common stock reserved for issuance under the Inducement Pool. Effective January 22, 2025, the number of shares of common stock available under the Inducement Pool increased by 2,000,000 shares. The Inducement Pool provides for the grant of non-qualified stock options and was approved by the Compensation Committee of the Board without stockholder approval pursuant to Rule 5635(c)(4) of the Nasdaq Listing Rules. As of September 30, 2026, there were 1,869,405 shares available for grant under the Inducement Pool.
Stock Options
The following table summarizes the Company’s stock option activity for the nine months ended September 30, 2026.
Number of Options | Weighted average exercise price | Weighted average remaining contractual term (years) | ||||||||||||||||||
Outstanding at December 31, 2025 | $ | |||||||||||||||||||
Granted | ||||||||||||||||||||
Forfeited | ( | |||||||||||||||||||
Exercised | ( | |||||||||||||||||||
Outstanding at September 30, 2026 | $ | |||||||||||||||||||
Vested and expected to vest as of September 30, 2026 | $ | |||||||||||||||||||
Exercisable at September 30, 2026 | $ | |||||||||||||||||||
Restricted Stock Units
The following table summarizes the Company’s restricted stock unit activity for the nine months ended September 30, 2026.
Number of Restricted Stock Units | Weighted Average Grant Date Fair Value per Share | |||||||||||||
Outstanding at December 31, 2025 | $ | |||||||||||||
Granted | ||||||||||||||
Outstanding at September 30, 2026 | $ | |||||||||||||
16
Summit Therapeutics Inc.
Notes to Unaudited Condensed Consolidated Financial Statements
(in thousands, except share and per share data)
Stock-Based Compensation Expense
The total stock-based compensation expense included in the Company’s unaudited condensed consolidated statements of operations and comprehensive loss was as follows:
| Three Months Ended September 30, | Nine Months Ended September 30, | |||||||||||||||||||||||||||||||||||||
| 2026 | 2025 | 2026 | 2025 | |||||||||||||||||||||||||||||||||||
| Research and development | $ | $ | $ | $ | ||||||||||||||||||||||||||||||||||
| General and administrative | ||||||||||||||||||||||||||||||||||||||
Total stock-based compensation expense | $ | $ | $ | $ | ||||||||||||||||||||||||||||||||||
The following summarizes stock-based compensation expense associated with each of the Company’s stock-based compensation arrangements:
| Three Months Ended September 30, | Nine Months Ended September 30, | |||||||||||||||||||||||||||||||||||||
| 2026 | 2025 | 2026 | 2025 | |||||||||||||||||||||||||||||||||||
Stock options | $ | $ | $ | $ | ||||||||||||||||||||||||||||||||||
Restricted stock units | ||||||||||||||||||||||||||||||||||||||
Employee stock purchase plan | ||||||||||||||||||||||||||||||||||||||
Total stock-based compensation expense | $ | $ | $ | $ | ||||||||||||||||||||||||||||||||||
During the second quarter of 2025, the Compensation Committee of the Board of Directors approved a modification to the Company's outstanding unvested performance-based stock option awards for certain employees and executives that will require only the service-based vesting requirements to continue to be satisfied in order to become fully vested, subject to employee consent. The Company accounted for this change as a Type III modification (improbable-to-probable) in accordance with the requirements of Accounting Standards Codification Topic 718 (ASC 718). As a result, 44,488,976 options were valued on the modification date. The Company is recognizing the newly assessed measurement date fair value of the awards as compensation expense over the remaining vesting period. During the three and nine months ended September 30, 2026, the Company recognized expense of $20,067 and $100,516 respectively associated with the modification. As of September 30, 2026, the unrecognized compensation cost associated with the modification was $70,739 and is expected to be expensed over a weighted-average recognition period of approximately 1.0 year.
12. Related Party Transactions
Leases
July 25, 2022 First Amendment to Sublease Agreement with Maky Zanganeh and Associates, Inc.
On July 25, 2022 the Company entered into a first amendment, dated July 19, 2022, to its existing sublease agreement with Maky Zanganeh and Associates, Inc. (“MZA”), an entity owned by Maky Zanganeh, consisting of 4,500 square feet of office space at 2882 Sand Hill Road, Menlo Park, California. The existing sublease term, which was set to expire on September 30, 2022, was extended for a period of thirty-nine months from October 1, 2022 through December 31, 2025. The rent payable under the terms of the sublease was equivalent to the proportionate share of the net payable by MZA to the third-party landlord, based on the square footage of office space sublet by the Company, and no mark-up had been applied. The agreement was further amended to include additional space, as noted below under the August 2, 2024 Third Amendment to Sublease Agreement with Maky Zanganeh and Associates, Inc. The first amendment was not extended following its expiration on December 31, 2025. During the three and nine months ended September 30, 2025, payments of $207 and $621 , respectively, were made pursuant to the first and third amendments to the Sublease Agreement.
17
Summit Therapeutics Inc.
Notes to Unaudited Condensed Consolidated Financial Statements
(in thousands, except share and per share data)
July 29, 2022 Second Amendment to Sublease Agreement with Maky Zanganeh and Associates, Inc.
On July 29, 2022, the Company entered into a second amendment to its existing sublease agreement with MZA, described above. The second amendment was effective as of August 1, 2022 and expired on December 31, 2025. The second amendment included an additional 1,277 square feet of office space at 2882 Sand Hill Road, Menlo Park, California. The rent payable under the terms of the sublease was equivalent to the proportionate share of the net payable by MZA to the third-party landlord, based on the square footage of office space sublet by the Company, and no mark-up had been applied. The second amendment was not extended following its expiration on December 31, 2025. During the three and nine months ended September 30, 2025, payments of $59 and $173 , respectively, were made pursuant to the second amendment to the Sublease Agreement.
April 1, 2024 Miami Sublease Agreements
On April 1, 2024, the Company entered into two sublease agreements of its Miami headquarters location, one with Genius 24C Inc. (“Genius”), an affiliate of the Company’s Co-CEO, Robert W. Duggan (the “Genius Sublease Agreement”) and one with Duggan Investments Research LLC (“Investments Research”), also an affiliate of the Company's Co-CEO, Robert W. Duggan (the “Investments Research Sublease Agreement”). Pursuant to the Genius Sublease Agreement, Genius sublet from the Company 848 square feet of office space in the Miami HQ for a sixty-two month term for total rental payments of approximately $446 . Pursuant to the Investments Research Sublease Agreement, Investments Research sublet from the Company 848 square feet of office space in the Miami HQ for a sixty-two month term for total rental payments of approximately $446 . Effective April 1, 2026, the Company provided notice to both Genius and Investments Research to terminate the Genius Sublease Agreement and Investments Research Sublease Agreement, respectively, in order to have more space for the Company’s use at Miami HQ. The Company did not incur any early termination penalties. For the nine months ended September 30, 2026, the Company recognized sublease income of $48 , which was recorded net of operating lease expenses. For the three and nine months ended September 30, 2025, the Company recognized sublease income of $46 and $140 , respectively, which was recorded net of operating lease expenses. As of December 31, 2025, sublease income receivable recorded as a component of prepaid expenses and other current assets on the unaudited condensed consolidated balance sheet was de minimis.
August 2, 2024 Third Amendment to Sublease Agreement with Maky Zanganeh and Associates, Inc.
On August 2, 2024, the Company entered into a third amendment to its existing sublease agreement with MZA. The third amendment was effective August 1, 2024 and included an additional space of 145 square feet of office space located at 2882 Sand Hill Road, Menlo Park, California. The Company was obligated to pay its proportionate share of the net payable by MZA to the third-party landlord, which was revised to 93.6 % as of the effective date, based on the square footage of office space sublet by the landlord. The third amendment was not extended following its expiration on December 31, 2025.
November 4, 2026 Sublease Agreement with Genius 24C, Inc.
On November 4, 2026, the Company entered into a sublease agreement with Genius, an affiliate of the Company’s Co-CEO, Robert W. Duggan (the “2026 Genius Sublease Agreement”). Pursuant to the 2026 Genius Sublease Agreement, effective November 1, 2026, the Company sublet from Genius 2,382 square feet of office space in the same facility as the Company’s headquarters in Miami, Florida for a twelve month term for a total rental payment of approximately $205 .
Akeso Agreements
Upon the closing of the License Agreement, the Board appointed Dr. Yu (Michelle) Xia to serve as a member of the Board pursuant to the terms of the License Agreement. Dr. Xia is the founder of Akeso, and has been the chairwoman, president and CEO of Akeso since its inception in 2012. Furthermore, in connection with the License Agreement, the Company agreed to purchase a certain portion of drug substance for clinical and commercial supply and to enter into a supply agreement with Akeso. Refer to Note 4 for details on the License Agreement. In addition to the License Agreement , the Company also entered into various clinical services agreements with Akeso. During the three and nine months ended September 30, 2026,
18
Summit Therapeutics Inc.
Notes to Unaudited Condensed Consolidated Financial Statements
(in thousands, except share and per share data)
the Company incurred research and development expenses of $23,395 and $65,985 , respectively, under these agreements with Akeso. During the three and nine months ended September 30, 2025, the Company incurred research and development expenses of $13,657 and $29,272 , respectively, under these agreements with Akeso. As of September 30, 2026 and December 31, 2025, the Company included in accrued liabilities, related to Akeso, $2,772 and $1,215 , respectively.
Financings
October 2025 PIPE
Refer to Note 9 for a discussion on the participation by related parties in October 2025 PIPE.
ATM Offering
During the second quarter of 2026, the Audit Committee and all independent directors of the Board of Directors approved one or more Company affiliates to purchase shares of the Company’s common stock under the ATM. During the nine months ended September 30, 2026, the Company’s Co-Chief Executive Officers and Chief Financial Officer and Chief Operating Officer purchased an aggregate of 3,960,000 shares of common stock under the ATM at a weighted-average price of $13.17 per share, for gross proceeds totaling $52,169 .
Warrants Exercise
In March 2025, Mr. Duggan, the Company’s Co-Chief Executive Officer, exercised 2,936,221 of the 3,985,055 warrants which he received in connection with a private placement completed by the Company with Mr. Duggan and other investors on December 24, 2019, resulting in the purchase of 2,936,221 shares of common stock at an exercise price of $1.58 .
On April 8, 2025, Mr. Duggan completed the exercise of the remaining warrants received in the December 24, 2019 private placement, resulting in the purchase of 1,048,834 shares of common stock at an exercise price of $1.58 .
Professional Services
During the nine months ended September 30, 2026 and 2025, the Company engaged the law firm Wilson Sonsini Goodrich & Rosati P.C. (“WSGR”), where Mr. Kenneth A. Clark, a member of the Board, is a partner. Payments to be made by the Company to WSGR were approved by the Audit Committee in accordance with its Related Party Transaction Policy. For the three and nine months ended September 30, 2026, the Company incurred costs related to legal services rendered by WSGR totaling approximately $174 and $209 , respectively. For the three and nine months ended September 30, 2025, the Company incurred expenses for legal services rendered by WSGR totaling approximately $723 and $1,354 , respectively.
13. Commitments and Contingencies
Fixed Asset Purchase Commitments
There were no material changes to the Company’s capital commitments that were disclosed in the Company’s Annual Report.
Lease Commitments
On July 23, 2025, the Company entered into an operating lease for 8,857 square feet of office space in Princeton, New Jersey (the “Princeton Lease Agreement”). The term of the Princeton Lease Agreement commenced on August 18, 2025 and was set to expire on August 31, 2028. The average annual lease payments under the Princeton Lease Agreement are approximately $292 . Subsequently, on April 15, 2026, the Company entered into an amendment to the Princeton Lease Agreement (the “Princeton Amendment”). The Princeton Amendment expands the office space by 6,350 square feet for a total 15,207 square feet, and extends the lease term through August 31, 2029. The average annual lease payments under the Princeton Lease Agreement, upon effect of the Princeton Amendment, will be approximately $507 .
19
Summit Therapeutics Inc.
Notes to Unaudited Condensed Consolidated Financial Statements
(in thousands, except share and per share data)
Except as noted above, there were no material changes to the Company’s lease commitments that were disclosed in the Company’s Annual Report.
Other Commitments
The Company enters into contracts in the normal course of business with various third parties for clinical trials, preclinical research studies and testing, manufacturing and other services and products for operating purposes. Most contracts provide for termination upon notice, and therefore are cancellable contracts. The majority of these commitments are due within one year . There have been no material changes to the Company’s other contractual commitments that were disclosed in the Company’s Annual Report.
The Company has certain commitments under its agreements with Akeso. The License Agreement also contains certain manufacturing and purchase commitments. As of September 30, 2026, the Company is unable to estimate the amount, timing or likelihood of achieving the milestones, making future product sales or assessing estimated forecasts for manufacturing and supplied materials which these contingent payment obligations relate to.
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Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations.
The following discussion and analysis of our financial condition and results of operations should be read in conjunction with our unaudited condensed consolidated financial statements and related notes included herein and our audited consolidated financial statements and related notes for the year ended December 31, 2025 included in our Annual Report. Some of the information contained in this discussion and analysis or set forth elsewhere in this filing, including information with respect to our plans and strategy for our business, includes forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended, that involve risks and uncertainties. All statements other than statements relating to historical matters including statements to the effect that we “believe,” “expect,” “anticipate,” “plan,” “target,” “intend” and similar expressions should be considered forward-looking statements. As a result of many factors, including those factors set forth in the risks identified in the “Risk Factors” section of our other filings with the Securities and Exchange Commission, our actual results could differ materially from the results, performance or achievements expressed in or implied by these forward-looking statements.
Company Overview
Summit Therapeutics Inc. (“we,” “Summit” or the “Company”) is a biopharmaceutical company focused on the discovery, development, and commercialization of patient-, physician-, caregiver- and societal-friendly medicinal therapies intended to improve quality of life, increase potential duration of life, and resolve serious unmet medical needs. The Company’s pipeline product candidate is designed with the goal to become patient-friendly, new-era standard-of-care medicine, in the therapeutic area of oncology.
The Company’s current lead development candidate is ivonescimab, a novel, potential first-in-class bispecific antibody intending to combine the effects of immunotherapy via a blockade of PD-1 with the anti-angiogenesis effects of an anti-VEGF compound into a single molecule. On December 5, 2022, the Company entered into the License Agreement with Akeso pursuant to which the Company has in-licensed intellectual property rights related to ivonescimab (as amended, the “License Agreement”). Through the License Agreement, the Company obtained the rights to develop and commercialize ivonescimab in the United States, Canada, Europe, and Japan. The License Agreement and transaction closed in January 2023 following customary waiting periods. On June 3, 2024, the Company entered into the Second Amendment with Akeso to expand its territories covered under the License Agreement to also include Latin America, including Mexico and all countries in Central America and South America, the Middle East and Africa. The Company’s operations are focused on the development of ivonescimab and other future activities, as the Company determines.
The Company is developing ivonescimab in non-small cell lung cancer (“NSCLC”), colorectal cancer (“CRC”), urothelial carcinoma (“UC”), and renal cell carcinoma (“RCC”) specifically conducting global Phase II or Phase III clinical trials in the following proposed indications:
(a) ivonescimab combined with chemotherapy in patients with epidermal growth factor receptor (“EGFR”)-mutated, locally advanced or metastatic non-squamous NSCLC who were previously treated with a third-generation EGFR tyrosine kinase inhibitor (“TKI”) (“HARMONi”; Phase III);
(b) ivonescimab combined with chemotherapy in patients with first-line metastatic NSCLC (including separate statistical analyses planned for patients with squamous NSCLC and non-squamous NSCLC) (“HARMONi-3”; Phase III);
(c) ivonescimab monotherapy in patients with first-line metastatic NSCLC whose tumors have high PD-L1 expression (“HARMONi-7”; Phase III);
(d) ivonescimab combined with chemotherapy in patients with first-line unresectable metastatic CRC (“HARMONi-GI3”; Phase III);
(e) ivonescimab combined with enfortumab vedotin in patients with first-line UC, also known as bladder cancer (“HARMONi-GU1”; Phase II/III); and
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(f) multiple ivonescimab-based combination treatment approaches in patients with incurable locally advanced or metastatic clear cell renal cell carcinoma (“ccRCC”) who have not received prior systemic therapy for advanced disease (“SMT112-216”, also referred to as “AK112-216”; Phase II).
In October 2024, the Company completed enrollment in its HARMONi clinical trial. In May 2025, we announced topline results from our double-blinded, placebo-controlled HARMONi study. The HARMONi study has dual primary endpoints: progression-free survival (“PFS”) and overall survival (“OS”). At the prespecified primary data analysis, ivonescimab in combination with chemotherapy demonstrated a statistically significant improvement in PFS, the magnitude of which we believe to be clinically meaningful, with a hazard ratio of 0.52 (95% CI: 0.41 – 0.66; p<0.00001) compared to placebo in combination with chemotherapy; median PFS was 6.8 months for those patients receiving ivonescimab plus chemotherapy compared to 4.4 months for those receiving chemotherapy. PFS was assessed by blinded independent central radiology committee (“BICR”).
We believe the PFS hazard ratio that was observed in both Asian and western sub-populations to be clinically meaningful. The primary analysis demonstrated the consistency of the magnitude of the PFS benefit between patients randomized in Asian and western territories, as well as the consistency in a single-region study (“HARMONi-A”) with this multiregional study.
In a longer-term follow-up of PFS, which included all western patients and at least six months of follow-up time for all patients, ivonescimab plus chemotherapy demonstrated a consistent improvement in PFS with an observed hazard ratio of 0.57 (95% CI: 0.46 – 0.71). With the longer-term follow-up analysis, consistency of the magnitude of PFS benefit was demonstrated between patients randomized in Asia and western patients when measured by hazard ratio. This longer-term follow-up analysis of PFS was performed at the time of the primary OS analysis.
Ivonescimab in combination with chemotherapy showed a positive trend in OS in the primary analysis without achieving a statistically significant benefit with a hazard ratio of 0.79 (95% CI: 0.62 – 1.01; p=0.057). This trend provides further support for its use in EGFR-mutated NSCLC after TKI therapy, a setting where high unmet need continues to exist with limited approved options in the United States and other western territories. Currently there are no FDA-approved regimens that have demonstrated a statistically significant OS benefit in this patient setting. Both Asian and North American patients demonstrated a positive trend in OS. The results of the primary analysis in this multiregional study were consistent with that of the single-region randomized Phase III HARMONi-A study, which demonstrated a statistically significant OS benefit with a hazard ratio of 0.74 in the primary OS analysis in a similar patient population.
In September 2025, an additional ad hoc OS analysis was performed for the HARMONi study, whereby the western patients were followed for a longer period of time (Asian patients were locked at the time of the primary analysis). In this analysis that included longer-term follow-up of western patients (median follow-up time of western patients of 13.7 months), a hazard ratio consistent with the primary analysis was observed with an improved nominal p-value (HR=0.78; 95% CI: 0.62 – 0.98; nominal p=0.0332). Median OS for this analysis remained the same in both arms as was observed in the primary analysis. Median OS in Western patients receiving ivonescimab was 17.0 months compared to 14.0 months for those receiving placebo (HR=0.84). The hazard ratios for Western patients in totality, as well as patients from the North American and European regions individually, improved from the primary OS analysis to the analysis with longer-term follow-up of Western patients. Consistent benefit was observed across pre-defined subgroups.
In July 2026, an updated analysis was conducted with a data cutoff date of June 2026 which analyzed OS when most western patients had discontinued treatment or completed two years of treatment. This analysis showed a consistent OS trend amongst western and Asian patients as western patients were followed for additional time on study reaching median follow-up of 23.2 months; Asian patients remained locked with a median follow-up time of 32.7 months from the primary analysis. The updated June 2026 analysis, which was presented as part of the Presidential Symposium at the International Association for the Study of Lung Cancer (“IASLC”) 2026 World Conference on Lung Cancer (“WCLC”), continued to show consistent, favorable OS results, with an OS hazard ratio of 0.76 (95% CI: 0.61 – 0.95; nominal p=0.0151) in the global intention-to-treat (“ITT”) population. An OS hazard ratio of 0.76 was demonstrated in the western patient subgroup (95% CI: 0.52 – 1.10), which was consistent with the ITT population and Asian subgroup. In this most recent analysis, ivonescimab continued to demonstrate an acceptable and manageable safety profile that was consistent with previous Phase III data of ivonescimab plus chemotherapy with no additional safety signals. These OS results have been made available to the FDA.
Based on the results of the HARMONi clinical trial, we submitted a Biologics License Application (“BLA”) in the fourth quarter of 2025 to seek approval for ivonescimab plus chemotherapy for this proposed indication. After careful consideration
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of the safety and efficacy profile of the current FDA-approved options for patients in this setting, the positive results of the Phase III multiregional study, including regional consistency, as well as discussions with key opinion leaders and those physicians who have administered ivonescimab to patients in a clinical study setting, we believe that the safety and efficacy data generated in the HARMONi study demonstrates that the ivonescimab regimen offers a potential treatment option for patients impacted by EGFR-mutated NSCLC in this setting with a favorable benefit-risk profile despite the lack of a statistically significant OS benefit. Summit announced in January 2026 that the FDA accepted for filing the BLA seeking approval for ivonescimab in combination with chemotherapy for this proposed indication. The FDA provided a Prescription Drug User Fee Act (“PDUFA”) goal action date of November 14, 2026. The FDA noted that a statistically significant OS benefit is necessary to support marketing authorization in this setting, and the PFS results from this study may not be sufficient to support marketing authorization.
The HARMONi-3 study (NCT05899608) is a Phase III, multi-regional, potentially registration-enabling clinical trial for which we initiated sites in North America, Asia and Europe. The dual primary endpoints for this study are PFS and OS, and the study compares ivonescimab plus platinum-based doublet chemotherapy versus pembrolizumab plus platinum-based doublet chemotherapy in first-line patients with metastatic squamous NSCLC and non-squamous NSCLC. Enrollment has been completed in both the squamous and non-squamous cohorts.
In October 2025, the Company announced a protocol amendment to separate the statistical analysis of the primary endpoints by histology. Therefore, there will be separate analyses conducted to evaluate ivonescimab plus chemotherapy compared to pembrolizumab plus chemotherapy in patients with squamous NSCLC and in patients with non-squamous NSCLC. In order to sufficiently power for both primary endpoints (PFS and OS) in both cohorts of this study, Summit enrolled approximately 600 patients with squamous NSCLC and 1,000 patients with non-squamous NSCLC.
As a result of having two separate ITT analyses within the HARMONi-3 study, the analyses for squamous tumors and non-squamous tumors may be conducted at separate times, as each analysis will be conducted upon the prespecified numbers of events being reached in the separate cohorts.
Patient enrollment was completed for the squamous cohort of HARMONi-3 in the first quarter of 2026. Previously, Summit announced its intention to perform an interim PFS analysis for the squamous cohort of the HARMONi-3 study in the second quarter of 2026. To achieve statistical significance, there was a meaningfully higher bar than the upcoming planned final PFS analysis based on the minimal alpha spent on the interim analysis. At this early PFS interim analysis reviewed exclusively by the Independent Data Monitoring Committee (“iDMC”), the iDMC recommended that the study continue as planned. No safety concerns were noted, and the study continues to be double-blinded. The number of PFS events needed in the squamous cohort for the primary analysis is expected to be reached in the fourth quarter of 2026, and a planned early interim analysis for OS is expected to take place in conjunction with the primary PFS analysis. An interim analysis for OS independent of PFS is planned for the first half of 2027.
Enrollment in the non-squamous cohort of the global HARMONi-3 study was completed in the second quarter of 2026. For this cohort, the number of events needed to conduct the PFS analysis is expected to be reached in the first half of 2027.
Akeso Collaboration and License Agreement
Pursuant to the License Agreement with Akeso, the Company received the rights to develop and commercialize ivonescimab in the Licensed Territory. Akeso retained development and commercialization rights for the rest of the world excluding the Licensed Territory. In exchange for these rights, Summit made an upfront payment during the first quarter of 2023 comprised of $474.9 million cash and the issuance of 10 million shares of Company common stock in lieu of $25.1 million cash pursuant to a share transfer agreement. Furthermore, on June 3, 2024, the Company entered into an amendment to the License Agreement with Akeso to expand its territories covered under the License Agreement to also include the Latin America, Middle East and Africa regions for which Summit paid an upfront payment of $15.0 million cash in the third quarter of 2024. In addition, the Company may also pay Akeso (a) milestone payments tied to achievement of regulatory approval of ivonescimab with various regulatory authorities in the Licensed Territory, (b) milestone payments tied to achievement of annual revenue from ivonescimab in the Licensed Territory and (c) royalty payments equal to low-double-digit percentage of annual revenues from ivonescimab in the Licensed Territory. In connection with the License Agreement, the Company
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agreed to purchase a certain portion of drug substance and/or drug product for clinical and commercial supply and to enter into a supply agreement with Akeso.
Pursuant to the terms of the License Agreement, Summit has final decision-making authority with respect to all of its commercialization activities including, but not limited to, commercial strategy, pricing and reimbursement in the Licensed Territory.
Summit has not assumed any liabilities (including contingent liabilities), nor acquired any physical assets or trade names, or hired or acquired any employees from Akeso in connection with the License Agreement.
AstraZeneca Equity Investment
On September 28, 2026, the Company entered into the AstraZeneca SPA for the issuance and sale by the Company of approximately 108,955 shares of Class A Convertible Preferred Stock at a price of $18,356.14 per share. Each share of Class A Preferred Stock, upon issuance, is convertible into 1,000 shares of common stock, for a total of 108,955,369 shares of common stock at a conversion price of $18.3561 per share. On October 5, 2026, the Company completed the closing of the AstraZeneca Equity Investment. In connection with the closing, the Company issued the Class A Preferred Stock to AstraZeneca and received gross proceeds of $2.0 billion before issuance costs.
The conversion of the Class A Preferred Stock is subject to the expiration and termination of the applicable waiting period of HSR and the Company obtaining stockholder approval of the Charter Amendment Proposal. The stockholders of the Company approved the Charter Amendment Proposal on November 4, 2026. The Class A Preferred Stock and the common stock issuable on conversion are subject to a one-year lock-up period after closing.
Other Collaboration Agreements
In June 2025, the Company entered into a clinical trial collaboration with Revolution Medicines Inc. (“RevMed”) to evaluate ivonescimab in combination with three RevMed RAS(ON) inhibitors (the “RevMed Collaboration”). In January 2026, the Company entered into a clinical trial collaboration with GSK plc to evaluate ivonescimab in combination with GSK’s novel B7-H3 ADC, risvutatug rezetecan, in multiple solid tumors (the “GSK Collaboration”). Neither the RevMed Collaboration nor the GSK Collaboration include upfront payments, milestone payments, or royalty sharing provisions. For the three and nine months ended September 30, 2026, there was no cash consideration exchanged in connection with either the RevMed Collaboration or the GSK Collaboration.
In July 2026, the Company entered into a clinical trial collaboration with Arcus Biosciences, Inc (“Arcus”) to evaluate ivonescimab in combination with Arcus’ novel inhibitor of hypoxia-inducible factor 2-alpha, casdatifan, in ccRCC (the “Arcus Collaboration”). Both Arcus and the Company will contribute to the cost of the clinical study and each will provide study drug for purposes of conducting the clinical trial. There are no additional milestone payments or royalty sharing provisions thereafter. As of September 30, 2026, the Company incurred $1 million under the Arcus Collaboration.
In September 2026, the Company entered into a clinical trial collaboration with AstraZeneca to evaluate ivonescimab in combination with AstraZeneca’s Claudin 18.2-targeting antibody-drug conjugate (“ADC”), sonesitatug vedotin, also referred to as sone-ve, in certain gastrointestinal cancer settings (the “AstraZeneca Collaboration”). Each company will contribute their respective compound for the combination studies to be conducted, and the parties will jointly contribute to the costs of such studies, which are intended to be sponsored by AstraZeneca. The AstraZeneca Collaboration does not include upfront payments, milestone payments, or royalty sharing provisions. Each company will retain development and commercial rights to their respective molecules.
Additionally in September 2026, the Company executed a non-binding memorandum of understanding with AstraZeneca whereby the two companies intend to enter into an agreement to conduct clinical trials combining ivonescimab with multiple AstraZeneca cancer medicines, including AstraZeneca’s leading portfolio of ADCs (the “AstraZeneca MOU”). Pursuant to the AstraZeneca MOU, the companies intend to share clinical development costs of potential future studies. Each company
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will retain their current development and commercial rights to their respective molecules, and the agreement is mutually non-exclusive. The AstraZeneca MOU does not include upfront payments, milestone payments, or royalty sharing provisions.
In October 2026, the Company entered into a clinical trial collaboration with AstraZeneca and Daiichi Sankyo (“Daiichi”) to evaluate ivonescimab in combination with TROP2-directed ADC, datopotamab deruxtecan (Datroway®), across multiple solid tumor settings, intending to include breast cancer and lung cancer (the “AZDS Collaboration”). The companies intend to begin with a Phase III trial in first-line triple-negative breast cancer (“TNBC”). The Company, and AstraZeneca and Daiichi, will contribute their respective compound for the combination studies to be conducted, and the parties will jointly contribute to the costs of such studies, which will be sponsored by AstraZeneca or Daiichi. The AZDS Collaboration does not include upfront payments, milestone payments, or royalty sharing provisions. The Company, and AstraZeneca and Daiichi, will retain development and commercial rights to their respective molecules.
Ivonescimab
Ivonescimab is a novel potential first-in-class PD-1 / VEGF-A bispecific antibody, believed to be the most advanced in clinical development in the Licensed Territory. Invented by Akeso, ivonescimab, as a single molecule, blocks programmed cell death protein 1 (“PD-1”) from binding to PD-L1 and PD-L2, and blocks the protein vascular endothelial growth factor-A (“VEGF”) from binding to VEGF receptors. Ivonescimab is designed to potentially allow cooperative binding of the intended targets, such that the binding of VEGF increases the binding affinity of PD-1. In view of the co-expression of VEGF and PD-1 in the tumor micro-environment (“TME”), ivonescimab may block these two pathways more effectively and enhance the antitumor activity, as compared to combination therapy through what is believed to be a unique cooperative binding mechanism.
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This could differentiate ivonescimab as there is potentially higher expression (presence) of both PD-1 and VEGF in tumor tissue and the TME as compared to normal tissue in the body. As shown in Akeso’s in-vitro studies, ivonescimab’s tetravalent structure (four binding sites) enables higher avidity (accumulated strength of multiple binding interactions) in the TME with over 10-fold increased binding affinity to PD-1 in the presence of VEGF. This tetravalent structure, the intentional novel design of the molecule, and bringing these two targets into a single bispecific antibody with cooperative binding qualities has 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 is currently being developed by both Akeso and the Company in multiple Phase III clinical trials. Over 5,000 patients have been treated with ivonescimab in clinical studies globally, and over 100,000 patients when considering those treated in a commercial setting in China as noted and updated by Akeso.
Product Pipeline
Summit Sponsored Ivonescimab Trials
Ivonescimab is currently being investigated in global Phase II and Phase III clinical trials. Additional Phase I, II, and III trials were completed by or are ongoing with our partner Akeso. This pipeline reflects Phase II and Phase III clinical trials that have been or are planned to be initiated by Summit in its Licensed Territory.
HARMONi
The HARMONi study (NCT06396065) is a Phase III, multi-regional, potentially registration-enabling clinical trial, which enrolled patients in North America, Europe, and China. Patients enrolled in China were also enrolled as a part of the HARMONi-A study. We completed enrollment of patients in North America and Europe in October 2024. The dual primary endpoints for this study are PFS and OS, and the study compares ivonescimab plus platinum-based doublet chemotherapy versus placebo plus platinum-based doublet chemotherapy in patients with advanced or metastatic EGFR-mutated NSCLC whose tumors have progressed following treatment with a third-generation EGFR-TKI.The dual primary endpoints were allocated separate alpha levels and tested individually. The alpha was recycled from the PFS to the OS analysis upon the successful achievement of the PFS endpoint.
In May 2025, we announced topline results from our double-blinded, placebo-controlled HARMONi study. At the prespecified primary data analysis, ivonescimab in combination with chemotherapy demonstrated a statistically significant improvement in PFS, the magnitude of which we believe to be clinically meaningful, with a hazard ratio of 0.52 (95% CI: 0.41 – 0.66; p<0.00001) compared to placebo in combination with chemotherapy; median PFS was 6.8 months for those patients receiving ivonescimab plus chemotherapy compared to 4.4 months for those receiving chemotherapy. PFS was assessed by BICR.
We believe the PFS hazard ratio that was observed in both Asian and western sub-populations to be clinically meaningful. The primary analysis demonstrated the consistency of the magnitude of the PFS benefit between patients randomized in Asia and western territories, as well as the consistency in a single-region study (HARMONi-A) with this multiregional study.
In a longer-term follow-up of PFS, which included all western patients and at least six months of follow-up time for all patients, ivonescimab plus chemotherapy demonstrated a consistent improvement in PFS with an observed hazard ratio of 0.57 (95% CI: 0.46 – 0.71). With the longer-term follow-up analysis, consistency of the magnitude of PFS benefit was demonstrated between patients randomized in Asia and western patients when measured by hazard ratio. This longer-term follow-up analysis of PFS was performed at the time of the primary OS analysis.
Ivonescimab in combination with chemotherapy showed a positive trend in OS in the primary analysis without achieving a statistically significant benefit with a hazard ratio of 0.79 (95% CI: 0.62 – 1.01; p=0.057). This trend provides further support for its use in EGFR-mutated NSCLC after TKI therapy, a setting where high unmet need continues to exist with limited approved options in the United States and other western territories. Currently, there are no FDA-approved regimens that have
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demonstrated a statistically significant OS benefit in this patient setting. Both Asian and North American patients demonstrated a positive trend in OS. The results of the primary analysis in this multiregional study were consistent with that of the single-region randomized Phase III HARMONi-A study, which demonstrated a statistically significant OS benefit hazard ratio of 0.74 in the primary OS analysis in a similar patient population.
In September 2025, an additional ad hoc OS analysis was performed for the HARMONi study whereby the western patients were followed for a longer period of time (Asian patients were locked at the time of the primary analysis). In this analysis that included longer-term follow-up of western patients (median follow-up time of western patients of 13.7 months), a hazard ratio consistent with the primary analysis was observed with an improved nominal p-value (HR=0.78; 95% CI: 0.62 – 0.98; nominal p=0.0332). Median OS for this analysis remained the same in both arms as was observed in the primary analysis. Median OS in western patients receiving ivonescimab was 17.0 months compared to 14.0 months for those receiving placebo (HR=0.84). The hazard ratios for western patients in totality, as well as patients from the North American and European regions individually, improved from the primary OS analysis to the analysis with longer-term follow-up of western patients. Consistent benefit was observed across pre-defined subgroups.
In July 2026, an updated analysis was conducted with a data cutoff date of June 2026 which analyzed OS when most western patients had discontinued treatment or completed two years of treatment. This analysis showed a consistent OS trend amongst western and Asian patients as western patients were followed for additional time on study reaching median follow-up of 23.2 months; Asian patients remained locked with a median follow-up time of 32.7 months from the primary analysis. The updated June 2026 analysis, which was presented as part of the Presidential Symposium at the 2026 WCLC, continued to show consistent, favorable OS results, with an OS hazard ratio of 0.76 (95% CI: 0.61 – 0.95; nominal p=0.0151) in the global ITT population. An OS hazard ratio of 0.76 was demonstrated in the western patient subgroup (95% CI: 0.52 – 1.10), which was consistent with the ITT population and Asian subgroup. In this most recent analysis, ivonescimab continued to demonstrate an acceptable and manageable safety profile, that was consistent with previous Phase III data of ivonescimab plus chemotherapy with no additional safety signals noted. These OS results have been made available to the FDA.
The safety profile of ivonescimab in combination with chemotherapy was acceptable and manageable in the context of the observed clinical benefit with comparable rates of discontinuation and death between both arms. There were 16 patients (7.3%) who discontinued ivonescimab due to treatment-related adverse events (“TRAEs”) compared to 11 patients (5.0%) who discontinued placebo due to TRAEs. There were four patients (1.8%) in the ivonescimab plus chemotherapy arm and five patients (2.3%) in the placebo-plus-chemotherapy arm who died as a result of TRAEs. In the ivonescimab plus chemotherapy arm, 50.0% of patients experienced Grade 3 or higher TRAEs compared to 42.2% in the placebo-plus chemotherapy arm. Of note, 0.9% of patients in the ivonescimab plus chemotherapy arm experienced Grade 3 or higher treatment-related hemorrhagic (bleeding) events.
Based on the results of the HARMONi clinical trial, Summit submitted a BLA in the fourth quarter of 2025 in order to seek U.S. approval for ivonescimab plus chemotherapy in this setting. Summit announced in January 2026 that the FDA accepted for filing the BLA, seeking approval for ivonescimab in combination with chemotherapy for this proposed indication. The FDA provided a PDUFA goal action date of November 14, 2026. The FDA noted that a statistically significant OS benefit is necessary to support marketing authorization in this setting, and the PFS results from this study may not be sufficient to support marketing authorization.
HARMONi-3
HARMONi-3 study (NCT05899608) is a Phase III, multi-regional, potentially registration-enabling clinical trial for which we initiated sites in North America, China and Europe. The dual primary endpoints for this study are PFS and OS, and the study compares ivonescimab plus platinum-based doublet chemotherapy versus pembrolizumab plus platinum-based doublet chemotherapy in first-line patients with metastatic squamous NSCLC and non-squamous NSCLC.
In October 2025, the Company announced a protocol amendment to separate the statistical analysis of the primary endpoints by histology. Therefore, there will be separate analyses conducted to evaluate ivonescimab plus chemotherapy compared to pembrolizumab plus chemotherapy in patients with squamous NSCLC and in patients with non-squamous NSCLC.
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In order to sufficiently power for both primary endpoints (PFS and OS) in both cohorts of this study, Summit plans to enroll approximately 600 patients with squamous NSCLC and 1,000 patients with non-squamous NSCLC.
As a result of having two separate intention-to-treat analyses within the HARMONi-3 study, the analyses for squamous tumors and non-squamous tumors may be conducted at separate times, as each analysis will be conducted upon the prespecified numbers of events being reached in the separate cohorts.
Patient enrollment was completed for the squamous cohort of HARMONi-3 in the first quarter of 2026. Previously, Summit announced its intention to perform an interim PFS analysis for the squamous cohort of the HARMONi-3 study in the second quarter of 2026. To achieve statistical significance, there was a meaningfully higher bar than the upcoming planned final PFS analysis based on the minimal alpha spent on the interim analysis. At this early PFS interim analysis reviewed exclusively by the iDMC, the iDMC recommended that the study continue as planned. No safety concerns were noted, and the study continues to be double-blinded. The number of PFS events needed in the squamous cohort for the primary analysis is expected to be reached in the fourth quarter of 2026, and a planned early interim analysis for OS is expected to take place in conjunction with the primary PFS analysis. An interim analysis for overall survival independent of PFS is planned for the first half of 2027.
Enrollment in the non-squamous cohort of the global HARMONi-3 study was completed in the second quarter of 2026. For this cohort, the number of events needed to conduct the PFS analysis is expected to be reached in the first half of 2027.
HARMONi-7
Based on the results of HARMONi-2, the Company is enrolling in the HARMONi-7 study (NCT06767514). HARMONi-7 is a multi-regional, potentially registration-enabling Phase III clinical trial that will compare ivonescimab monotherapy to pembrolizumab monotherapy in patients with metastatic squamous and non-squamous NSCLC whose tumors have high PD-L1 expression. The sample size for this study is currently planned to have an estimated 780 patients with dual primary endpoints, PFS and OS.
HARMONi-GI3
In the fourth quarter of 2025, the Company activated trial sites and began enrolling patients in HARMONi-GI3, a Phase III, multi-regional, clinical trial evaluating ivonescimab plus chemotherapy compared to bevacizumab plus chemotherapy as first line therapy in patients with unresectable metastatic CRC. The primary endpoint for this study is PFS and Summit plans to enroll approximately 900 patients. Enrollment is currently expected to be completed in the third quarter of 2027.
HARMONi-GU1
On August 5, 2026, the Company announced the expansion of its global registration-enabling clinical development program for ivonescimab into urothelial carcinoma, or bladder cancer, with the planned initiation of the global, multi-regional Phase II/III HARMONi-GU1 trial (“HARMONi-GU1”). HARMONi-GU1 will evaluate ivonescimab plus the antibody-drug conjugate enfortumab vedotin (“EV”) compared to pembrolizumab plus EV as first-line therapy in patients with previously untreated locally advanced or metastatic urothelial carcinoma. Global clinical trial site activations for and enrollment in HARMONi-GU1 has begun for the Phase II portion of this study.
SMT112-216 / AK112-216
On October 19, 2026, the Company announced the initiation and opening of trial sites for SMT112-216, a global Phase II study of ivonescimab in previously untreated advanced ccRCC. The study, also referred to as AK112-216, is being conducted in collaboration with Summit’s partner, Akeso Inc. SMT112-216 is a randomized, open-label Phase II clinical study designed to evaluate the safety and efficacy of multiple ivonescimab-based treatment approaches in patients with incurable locally advanced or metastatic ccRCC who have not received prior systemic therapy for advanced disease. The study plans to enroll approximately 100 patients at clinical trial sites in the U.S. and China. Participants will be randomized to receive ivonescimab in combination with cadonilimab, ivonescimab in combination with ipilimumab, ivonescimab monotherapy, or
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nivolumab plus ipilimumab as an established standard-of-care comparator regimen. Cadonilimab is an investigational PD-1 / CTLA-4 bispecific antibody developed by Akeso. This study is in addition to Summit’s clinical trial collaboration with Arcus evaluating ivonescimab in combination with casdatifan, a HIF2α inhibitor, in a similar ccRCC setting.
Cooperative Group-Sponsored Phase III Clinical Studies (Summit’s License Territories)
In the first quarter of 2026, the Company announced a collaboration with Groupe d'Oncologie Radiothérapie Tête Et Cou or Head and Neck Oncology and Radiotherapy Group (“GORTEC”), a cooperative group dedicated to Head and Neck Oncology, to initiate the Phase III clinical study, ILLUMINE (NCT07264075), which will evaluate ivonescimab monotherapy and ivonescimab in combination with ligufalimab, Akeso’s proprietary anti-CD47 monoclonal antibody, against monotherapy pembrolizumab in a three-arm study. Sponsored by GORTEC, the study is intended to be conducted in multiple countries in Europe and in China; Summit will consider the expansion of this study into the United States. The primary endpoint for the study is OS. The study, currently planned to enroll 780 patients with recurrent or metastatic PD-L1 positive head and neck squamous cell carcinoma (“HNSCC”), began enrollment in the second quarter of 2026. Data supporting this study was previously presented at the 2024 European Society for Medical Oncology Annual Congress (“ESMO”), whereby ivonescimab in combination with ligufalimab demonstrated an objective response rate of 60% in 20 patients with a median PFS of 7.1 months after a median follow-up time of 4.1 months; OS was not mature at the time of this analysis. At the time of data cut-off for this presentation, no patients receiving ivonescimab plus ligufalimab permanently discontinued drug treatment due to treatment-related adverse events.
In the fourth quarter of 2026, the Company announced a clinical collaboration with ECOG-ACRIN Cancer Research Group (“ECOG-ACRIN”), a scientific organization focused on innovative multicenter clinical trials, to initiate the registration-enabling Phase II/III clinical study, EA2251 (NCT07765433), evaluating ivonescimab in combination with chemotherapy compared to pembrolizumab or durvalumab in combination with chemotherapy in advanced biliary tract cancer (“BTC”). Sponsored by ECOG-ACRIN, the primary endpoint for the study is OS. Activation of U.S. clinical trial sites is expected to begin in the fourth quarter of 2026. Data supporting EA2251 was previously presented at ESMO 2026 via HARMONi-GI1, a single-region Phase III study from China sponsored by Akeso, which is further described below.
Potential Future Clinical Development and Additional Current Activities
Summit is conducting its current clinical trials and plans to design and conduct additional clinical trial activities for ivonescimab within its Licensed Territory to support and submit relevant regulatory filings. We intend to explore further clinical development of ivonescimab in solid tumor settings.
In the fourth quarter of 2023, we began collaborating with multiple institutions globally and opened our investigator- sponsored trials program across several disease areas. We have continued to expand this program in order to discover additional opportunities for ivonescimab, including in several tumors outside of our current development plan.
We plan to review the data generated from these clinical trials as well as Akeso-sponsored clinical trials as a part of our consideration for advancing our clinical development pipeline for ivonescimab in the Licensed Territory.
Additional Ivonescimab Development: Akeso-Sponsored Trials
Akeso is currently developing ivonescimab in NSCLC and other solid tumor settings. Ivonescimab was approved by the National Medical Products Administration (the “NMPA”) in May 2024 in China in combination with chemotherapy for patients with EGFR-mutated NSCLC whose tumors have progressed following an EGFR-TKI based on the results of the HARMONi-A clinical trial. Subsequently, ivonescimab was approved by the NMPA in April 2025 as monotherapy based on the results of the HARMONi-2 study in first-line, PD-L1 positive NSCLC. Also in October 2025, Akeso announced the positive data for the HARMONi-6 study in first-line squamous NSCLC for ivonescimab in combination with chemotherapy. In August 2026, ivonescimab was approved by the NMPA in combination with chemotherapy for the first-line treatment of patients with advanced squamous NSCLC based on the results of the HARMONi-6 study. Further details related to these three trials, in addition to other Phase II clinical data, are described further below. Akeso is currently conducting Phase III clinical trials in combination with chemotherapy in first-line biliary tract cancer (“HARMONi-GI1”), in first-line advanced
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PD-L1 low or negative TNBC (“HARMONi-BC1”), in first-line advanced microsatellite stable CRC (“HARMONi-GI6”) and in NSCLC for patients whose tumors have progressed following PD-(L)1 inhibitor based therapy (“HARMONi-8A”), as well as in combination with ligufalimab, a proprietary Akeso-owned investigational CD-47 monoclonal antibody, in first-line recurrent / metastatic PD-L1 positive head-and-neck cancer (“HARMONi-HN1”) and in combination with ligufalimab plus chemotherapy in first-line advanced pancreatic cancer (“HARMONi-GI2”). In addition, Akeso is conducting a Phase III study with ivonescimab after consolidation chemotherapy and radiotherapy in the limited stage small cell lung cancer setting (“HARMONi-9”).
HARMONi-A
Based on data published by Akeso at the 2024 American Society of Clinical Oncology Annual Meeting (“ASCO”) and in a publication in the Journal of the American Medical Association (“JAMA”) in the HARMONi-A study, in a single-region (China), randomized, double-blinded Phase III study in patients with NSCLC who have progressed following an EGFR-TKI, ivonescimab achieved its primary endpoint of PFS when combined with doublet chemotherapy (pemetrexed and carboplatin). Patients experienced a 54% reduction in disease progression or death as compared to placebo plus doublet-chemotherapy (HR: 0.46, 95% CI: 0.34 - 0.62; p<0.001). In a pre-specified subgroup analysis of patients who received a previous third-generation TKI, a hazard ratio of 0.48 was observed. At the primary OS analysis of HARMONi-A, ivonescimab achieved a hazard ratio of 0.74 (95% CI: 0.58, 0.95, p=0.019), demonstrating a statistically significant and clinically meaningful OS benefit, which was presented in November 2025 at the 2025 Annual Meeting for the Society for Immunotherapy for Cancer. Ivonescimab demonstrated an acceptable and manageable safety profile, which was consistent with previous studies. There were nine patients (5.6%) who discontinued ivonescimab plus chemotherapy due to TRAEs compared to four patients (2.5%) who discontinued chemotherapy plus placebo due to TRAEs. No TRAEs resulted in the death of a patient in either arm in this Phase III study. Full results were published in JAMA (Fang et al. 2024).
HARMONi-2
After announcing positive qualitative results on May 30, 2024 for the HARMONi-2 trial, a randomized, single-region (China) Phase III study sponsored by Akeso, quantitative data was presented on September 8, 2024 from the primary analysis as part of the Presidential Symposium at 2024 WCLC. The HARMONi-2 presentation evaluated monotherapy ivonescimab compared to monotherapy pembrolizumab in patients with locally advanced or metastatic NSCLC whose tumors have positive PD-L1 expression. HARMONi-2 is a single region, multi-center, double-blinded Phase III study conducted in China sponsored by Akeso, with all relevant data exclusively generated, managed, and analyzed by Akeso.
In the HARMONi-2 primary analysis, ivonescimab monotherapy demonstrated a statistically significant improvement in the trial’s primary endpoint, PFS by Independent Radiologic Review Committee (“IRRC”), when compared to monotherapy pembrolizumab, achieving a hazard ratio of 0.51 (95% CI: 0.38, 0.69; p<0.0001). A clinically meaningful benefit was demonstrated across clinical subgroups, including patients with tumors with high PD-L1 expression. OS data was not yet mature at the time of the data cutoff of the primary PFS analysis.
Ivonescimab demonstrated an acceptable and manageable safety profile, which was consistent with previous studies. There were three patients (1.5%) who discontinued ivonescimab due to TRAEs compared to six patients (3.0%) who discontinued pembrolizumab due to TRAEs. There was one patient in the ivonescimab arm and two patients in the pembrolizumab arm who died as a result of TRAEs in this Phase III study. Full results were published in Lancet (Xiong et al. 2025).
On April 25, 2025, Akeso announced that ivonescimab was approved in China by the NMPA for a second indication based on the results of the HARMONi-2 trial. As a part of the review of the supplemental marketing application submitted by Akeso seeking a label expansion of ivonescimab in China, the NMPA requested that Akeso perform an interim analysis of OS. Akeso announced that the results of this interim OS analysis included a clinically meaningful hazard ratio of 0.777. The analysis was conducted at 39% data maturity, with a nominal alpha level of 0.0001 that had not reached statistical significance.
On September 13, 2026, detailed clinical trial results of the HARMONi-2 study, including interim OS, were presented as part of the Presidential Symposium at WCLC 2026. In this protocol-specified interim analysis of OS, a secondary endpoint in
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the HARMONi-2 study, ivonescimab monotherapy demonstrated a statistically significant and clinically meaningful improvement compared to pembrolizumab monotherapy, achieving a hazard ratio of 0.73 (95% CI: 0.57, 0.95; p=0.009). A clinically meaningful benefit was demonstrated across important clinical subgroups, including those with PD-L1 low expression (PD-L1 Score 1-49%) and PD-L1 high expression (PD-L1 Score ≥ 50%), along with those with squamous and non-squamous histologies. In this analysis, ivonescimab continued to demonstrate an acceptable and manageable safety profile in the HARMONi-2 study, which was consistent with previous Phase III studies of ivonescimab. No additional safety signals were noted in the HARMONi-2 study in this current data cut with longer treatment duration (median of 14 cycles of ivonescimab vs. 10 cycles of pembrolizumab) compared to the previous data cut.
HARMONi-6
After announcing positive qualitative results for the HARMONi-6 trial on April 23, 2025, detailed clinical trial results of the study were presented as part of ESMO 2025. Additionally, positive OS data from the HARMONi-6 trial was presented on May 31, 2026 as a late breaking abstract for the plenary session at ASCO 2026. The HARMONi-6 study evaluated ivonescimab in combination with platinum-based chemotherapy compared to tislelizumab (a PD-1 inhibitor) in combination with platinum-based chemotherapy in patients with previously untreated advanced NSCLC irrespective of PD-L1 expression. HARMONi-6 is a single region, multi-center, double-blinded Phase III study conducted in China sponsored by Akeso, with all relevant data exclusively generated, managed, and analyzed by Akeso.
In the HARMONi-6 planned PFS interim analysis with a data cutoff date of February 2025 and median follow-up time of 10.28 months, ivonescimab in combination with chemotherapy demonstrated a statistically significant improvement in the primary endpoint, PFS, by IRRC, when compared to tislelizumab in combination with chemotherapy, achieving a hazard ratio of 0.60 (95% CI: 0.46, 0.78; p<0.0001). Subsequently, as published in the Chinese package insert (commonly referred to as the “label”), with a data cutoff date of September 2025 and median follow-up time of 17.02 months, the hazard ratio was 0.72 (95% CI: 0.58, 0.91; nominal p=0.003).
In the HARMONi-6 planned interim analysis of OS with a data cutoff date of February 2026 and median follow-up time of 21.36 months, ivonescimab in combination with chemotherapy demonstrated a statistically significant improvement when compared to tislelizumab in combination with chemotherapy, with a hazard ratio of 0.66 (95% CI: 0.50, 0.87; p=0.0017). For both PFS and OS, a clinically meaningful benefit was demonstrated across clinical subgroups, including those with either PD-L1 negative or positive expression.
Ivonescimab demonstrated an acceptable and manageable safety profile in the HARMONi-6 study, which was consistent with previous Phase III studies conducted studying ivonescimab. 14 patients (5.3%) discontinued ivonescimab plus chemotherapy due to TRAEs compared to 12 patients (4.5%) receiving tislelizumab plus chemotherapy due to TRAEs. There were 10 patients in the ivonescimab plus chemotherapy arm and 11 patients in the tislelizumab plus chemotherapy arm who died as a result of TRAEs in this Phase III study. Results were published in Lancet (Lu et al. 2026).
In August 2026, Akeso announced receipt of marketing authorization in China from the NMPA for the use of ivonescimab, in combination with chemotherapy for the first-line treatment of patients with advanced squamous NSCLC.
HARMONi-GI1
After announcing positive qualitative results for the HARMONi-GI1 trial on August 25, 2026, detailed clinical trial results of the study were presented as part of the Presidential Symposium at ESMO 2026. The randomized Phase III HARMONi-GI1 study (“HARMONi-GI1”) evaluating ivonescimab plus chemotherapy compared with durvalumab plus chemotherapy as a first-line treatment for patients with advanced BTC. HARMONi-GI1 is a single-region, multi-center, Phase III study conducted in China and sponsored by Akeso, with all relevant data exclusively generated, managed, and analyzed by Akeso.
In the HARMONi-GI1 interim analysis of OS, ivonescimab in combination with chemotherapy demonstrated a statistically significant improvement when compared to durvalumab in combination with chemotherapy, with a hazard ratio of 0.75 (95% CI: 0.61, 0.92; p=0.0031). OS rates at 12 and 18 months were 59.7% and 44.0%, respectively, for those patients receiving
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ivonescimab plus chemotherapy, compared to 50.7% and 32.5%, respectively, for those receiving durvalumab plus chemotherapy. Median follow-up time of the current data cut was 14.3 months.
In the HARMONi-GI1 study, ivonescimab plus chemotherapy demonstrated an acceptable and manageable safety profile which was consistent with previous Phase III studies of ivonescimab plus chemotherapy. No additional safety signals were identified.
Additional Phase II Data Sets
In addition to the HARMONi-2 data announced at WCLC 2024, Akeso also announced Phase II trial results from AK112-205, for patients with Stage II or III resectable NSCLC. Further, the Company announced data for ivonescimab was presented as a part of ESMO 2024 featuring updated Phase II ivonescimab data in advanced TNBC, for which subsequent updates to the data have been presented thereafter, recurrent / metastatic HNSCC, and metastatic microsatellite-stable CRC. At ASCO 2024, Akeso presented ivonescimab Phase II data in biliary-tract cancer. Earlier, at the 2024 European Lung Cancer Conference, Akeso announced updated data from AK112-201 (Cohort 1), a Phase II study for patients with first-line advanced NSCLC. Each trial from which the data was generated was a multi-center Phase II study conducted in China sponsored by Akeso, with data generated and analyzed by Akeso.
Additionally, at ASCO 2026, Summit presented new global Phase II ivonescimab data in metastatic microsatellite-stable CRC. Data generated was from a multi-center Phase II study conducted in the U.S. and China co-sponsored by Summit and Akeso, with data generated and analyzed by Summit and Akeso.
Results of Operations
Amounts reported in millions within this Quarterly Report on Form 10-Q are computed based on the amounts in thousands, and therefore, the sum of components may not equal the total amount reported in millions due to rounding.
The following table sets forth our results of operations for the three and nine months ended September 30, 2026 and 2025:
| Three Months Ended September 30, | Nine Months Ended September 30, | |||||||||||||||||||||||||||||||||||||
| (in millions) | 2026 | 2025 | $ Change | 2026 | 2025 | $ Change | ||||||||||||||||||||||||||||||||
| Operating expenses: | ||||||||||||||||||||||||||||||||||||||
| Research and development | $ | 169.1 | $ | 131.1 | $ | 38.0 | $ | 459.5 | $ | 390.4 | $ | 69.1 | ||||||||||||||||||||||||||
| General and administrative | 45.5 | 103.1 | (57.6) | 170.8 | 479.1 | (308.3) | ||||||||||||||||||||||||||||||||
| Total operating expenses | 214.6 | 234.2 | (19.6) | 630.3 | 869.5 | (239.2) | ||||||||||||||||||||||||||||||||
| Other income, net | 6.2 | 2.4 | 3.8 | 16.8 | 9.1 | 7.7 | ||||||||||||||||||||||||||||||||
| Net loss | $ | (208.4) | $ | (231.8) | $ | (23.4) | $ | (613.5) | $ | (860.4) | $ | (246.9) | ||||||||||||||||||||||||||
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Research and Development Expenses
The table below summarizes our research and development expenses by category for the three and nine months ended September 30, 2026 and 2025, respectively.
| Three Months Ended September 30, | Nine Months Ended September 30, | |||||||||||||||||||||||||||||||||||||
| (in millions) | 2026 | 2025 | $ Change | 2026 | 2025 | $ Change | ||||||||||||||||||||||||||||||||
Third-party research and development expenses: | ||||||||||||||||||||||||||||||||||||||
Clinical trial related expenses | $ | 67.2 | $ | 38.7 | $ | 28.5 | $ | 189.1 | $ | 92.1 | $ | 97.0 | ||||||||||||||||||||||||||
Expenses related to manufacturing and purchasing of clinical trial related materials | 47.8 | 30.8 | 17.0 | 114.6 | 71.4 | 43.2 | ||||||||||||||||||||||||||||||||
Other external research and development expenses | 7.6 | 5.7 | 1.9 | 23.5 | 15.9 | 7.6 | ||||||||||||||||||||||||||||||||
Internal research and development expenses: | ||||||||||||||||||||||||||||||||||||||
Compensation related costs, excluding stock-based compensation | 22.6 | 15.3 | 7.3 | 59.9 | 37.7 | 22.2 | ||||||||||||||||||||||||||||||||
| Stock-based compensation | 23.9 | 40.6 | (16.7) | 72.4 | 173.3 | (100.9) | ||||||||||||||||||||||||||||||||
| Total | $ | 169.1 | $ | 131.1 | 38.0 | $ | 459.5 | $ | 390.4 | $ | 69.1 | |||||||||||||||||||||||||||
Research and development expenses increased $38.0 million during the three months ended September 30, 2026 and increased $69.1 million during the nine months ended September 30, 2026, respectively, compared to the same periods in the prior year. The increase in third-party research and development expenses for the three and nine months ended September 30, 2026, was primarily driven by a $28.5 million and $97.0 million increase in clinical trial related expenses, respectively, a $17.0 million and $43.2 million increase in expenses related to manufacturing and purchasing of clinical trial related materials as a result of increased enrollment in our HARMONi-3, HARMONi-7, and HARMONi-GI3 trials and expenses related to start-up activities of our HARMONi-GU1 trial, respectively, and a $1.9 million and $7.6 million increase in other external research and development expenses, respectively. The decrease in internal research and development expenses for the three and nine months ended September 30, 2026, was primarily driven by a $16.7 million and $100.9 million decrease in stock-based compensation expense respectively, as a result of the modification to our performance-based stock option awards during the second quarter of 2025, which is offset by a $7.3 million and $22.2 million increase in compensation related costs, excluding stock-based compensation, respectively, as we continue to hire additional resources to support the clinical development of ivonescimab. We expect research and development expenses to continue to increase as we progress with the development of ivonescimab.
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General and Administrative Expenses
The table below summarizes our general and administrative expenses by category for the three and nine months ended September 30, 2026 and 2025, respectively.
| Three Months Ended September 30, | Nine Months Ended September 30, | |||||||||||||||||||||||||||||||||||||
| (in millions) | 2026 | 2025 | $ Change | 2026 | 2025 | $ Change | ||||||||||||||||||||||||||||||||
Compensation related costs, excluding stock-based compensation | $ | 10.2 | $ | 6.2 | $ | 4.0 | $ | 27.2 | $ | 16.4 | $ | 10.8 | ||||||||||||||||||||||||||
| Stock-based compensation | 23.8 | 90.2 | (66.4) | 116.8 | 447.4 | (330.6) | ||||||||||||||||||||||||||||||||
| Legal fees and professional services | 5.9 | 3.3 | 2.6 | 17.0 | 9.3 | 7.7 | ||||||||||||||||||||||||||||||||
| Other general and administrative expenses | 5.6 | 3.4 | 2.2 | 9.8 | 6.0 | 3.8 | ||||||||||||||||||||||||||||||||
| Total | $ | 45.5 | $ | 103.1 | $ | (57.6) | $ | 170.8 | $ | 479.1 | $ | (308.3) | ||||||||||||||||||||||||||
General and administrative expenses decreased by $57.6 million and $308.3 million for the three and nine months ended September 30, 2026 respectively, compared to the same periods in the prior year. The decrease was primarily driven by a $66.4 million and $330.6 million decrease in stock-based compensation respectively, as a result of the modification to our performance-based stock option awards during the second quarter of 2025. In addition, compensation related costs, excluding stock-based compensation, increased by $4.0 million and $10.8 million for the three and nine months ended September 30, 2026 respectively, compared to the same periods in the prior year due to increased headcount. Additionally, legal fees and professional services increased by $2.6 million and $7.7 million for the three and nine months ended September 30, 2026 respectively, compared to the same periods in the prior year to continue supporting the development of ivonescimab. We expect general and administrative expenses to continue to increase as we scale our infrastructure and increase our headcount to support the development of ivonescimab.
Other Income, net
The table below summarizes our other income by category for the three and nine months ended September 30, 2026 and 2025, respectively.
| Three Months Ended September 30, | Nine Months Ended September 30, | |||||||||||||||||||||||||||||||||||||
| (in millions) | 2026 | 2025 | $ Change | 2026 | 2025 | $ Change | ||||||||||||||||||||||||||||||||
| Foreign currency loss | $ | (0.3) | $ | (0.4) | $ | 0.1 | $ | (0.4) | $ | (0.5) | $ | 0.1 | ||||||||||||||||||||||||||
Investment income | 6.5 | 2.8 | 3.7 | 16.7 | 9.6 | 7.1 | ||||||||||||||||||||||||||||||||
Other (1) | — | — | — | 0.5 | — | 0.5 | ||||||||||||||||||||||||||||||||
Total | $ | 6.2 | $ | 2.4 | $ | 3.8 | $ | 16.8 | $ | 9.1 | $ | 7.7 | ||||||||||||||||||||||||||
(1) In June 2026, the Company entered into an asset purchase agreement (the “APA”) with a third party. Pursuant to the APA, the Company sold the asset relating to the pharmaceutical compound known as ridinilazole. In consideration for such assignment of rights, the third party has made an upfront non-refundable payment to the Company of $0.5 million. Additionally, the third party has also agreed to make additional payments totaling $1.5 million that are contingent upon the achievement of certain regulatory milestones, sales-based milestone payments of up to $103 million, as well as quarterly royalty payments that are based on a single digit percentage of net sales for certain products covered by the assigned and transferred patent rights. The Company did not have any amounts capitalized related to the underlying portfolio of patents, nor was any write-down of assets recorded upon executing the APA. The Company received the payment of $0.5 million from the third party in June 2026 and recognized the $0.5 million within other income, net on the condensed consolidated statements of operations and comprehensive loss for the nine months ended September 30, 2026. The Company does not have any ongoing obligations associated with the APA. As of September 30, 2026, the Company is unable to estimate the timing
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or likelihood of achieving the regulatory milestone payments, sales-based milestone payments, and the quarterly royalty payments.
For the three and nine months ended September 30, 2026, other income, net increased by $3.8 million and $7.7 million, compared to the same periods in the prior year, primarily due to an increase of $3.7 million and $7.1 million in investment income due to higher cash equivalents and short-term investments balance, respectively.
Liquidity and Capital Resources
Sources of Liquidity
As of September 30, 2026, we have financed our operations primarily through issuances of our common stock, including our most recent private placements issued in October 2025 and September 2024 for gross proceeds of $500.0 million and $235.0 million, respectively, and the raise of $475.7 million gross proceeds from our Distribution Agreement and Second Distribution Agreement, issuance of debt, and receipt of payments to us under license and collaboration arrangements. The remaining gross proceeds available under the Second Distribution Agreement as of September 30, 2026 was approximately $354.3 million. In October 2026, we received gross proceeds of $2.0 billion in connection with the closing of the AstraZeneca Equity Investment.
We have devoted substantially all of our efforts to research and development, including clinical trials. We have not completed the development of any drugs. We expect to continue to incur significant expenses and increasing operating losses for at least the next few years. The net losses we incur may fluctuate significantly from quarter to quarter and year to year, due to the nature and timing of our research and development activities. We expect that our research and development and general and administrative expenses will continue to be significant in connection with our ongoing research and development efforts. In addition, if we obtain marketing approval for any of our product candidates in the United States or other jurisdictions where we retain commercial rights, and if we choose to retain those rights, we would expect to incur significant sales, marketing, distribution and outsourced manufacturing expenses, as well as ongoing research and development expenses. In addition, our expenses will increase if and as we:
•invest in clinical development of ivonescimab in our Licensed Territory;
•conduct research and continue development of additional product candidates;
•maintain and augment our intellectual property portfolio and opportunistically acquire complementary intellectual property;
•seek further regulatory advancement for ivonescimab;
•invest in our manufacturing capabilities for ivonescimab and any other products for which we may obtain regulatory approval;
•seek marketing approvals for any product candidates that successfully complete clinical development;
•ultimately establish a sales, marketing and distribution infrastructure in jurisdictions where we have retained commercialization rights and scale up external manufacturing capabilities to commercialize any product candidates for which we receive marketing approval;
•perform our obligations under our collaboration agreements;
•pursue business development opportunities, including investing in other businesses, products and technologies;
•experience any delays or encounter any issues with any of the above, including but not limited to failed studies, complex results, safety issues or other regulatory challenges;
•hire additional clinical, regulatory, scientific and administrative personnel;
•expand our physical presence;
•add operational, financial and management information systems and personnel, including personnel to support our product development and planned future commercialization efforts; and
•borrow capital to fund our resources and have to pay interest expenses on such borrowings.
During the three and nine months ended September 30, 2026, we incurred a net loss of $208.4 million and $613.5 million, respectively, and cash used in operating activities for the nine months ended September 30, 2026 was $423.2 million. As of
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September 30, 2026, we had an accumulated deficit of $2,907.7 million, cash and cash equivalents of $150.8 million and short-term investments of $479.0 million. We expect to continue to generate operating losses for the foreseeable future.
Subsequent to the quarter ended September 30, 2026, the Company received gross proceeds of $2.0 billion from AstraZeneca in connection with the closing of the AstraZeneca Equity Investment. With the AstraZeneca Equity Investment, the Company has evaluated and concluded that its cash, cash equivalents and short-term investments provide sufficient cash to fund its operating cash needs for at least the next 12 months from the date of issuance of these condensed consolidated financial statements.
From time to time, we may raise additional equity or debt capital through both registered offerings off of a shelf registration, including ATM offerings, and private offerings of securities. On February 20, 2024, we filed a shelf registration statement on Form S-3 with the SEC, which the SEC declared effective on February 27, 2024. Through our shelf registration statement, we may, from time to time, sell up to an aggregate of $450 million of our common stock, preferred stock, debt securities, depository shares, warrants, subscription rights, purchase contracts, or units. Of the $450 million of liquidity available to us under this shelf registration statement, on May 13, 2024, we had established an ATM offering program with J.P. Morgan Securities LLC, as sales agent, in the amount of up to $90.0 million.
On August 11, 2025, we entered into the Amendment to the Original Distribution Agreement. Pursuant to the Amendment, the Original Distribution Agreement was amended to, among other things, increase the aggregate offering price of shares of the Company’s common stock, par value $0.01 per share, from time to time, through the sales agent, by up to an additional $360.0 million. As of September 30, 2026, the full $360.0 million of additional capacity provided by the Amendment had been utilized.
On July 23, 2026, we entered into an ATM sales agreement (the “Second Distribution Agreement”), pursuant to which we may offer and sell from time to time through the sales agent, shares of our common stock, par value $0.01 per share, having an aggregate offering price of up to $380,000. The remaining gross proceeds available under the Second Distribution Agreement as of September 30, 2026 was approximately $354.3 million.
In addition to the payments already made to Akeso under the License Agreement and Second Amendment, there are additional potential milestone payments of $4.56 billion, as Akeso will be eligible to receive regulatory milestones of up to $1.05 billion and commercial milestones of up to $3.51 billion. In addition, Akeso will be eligible to receive low double-digit royalties on net sales. Until we can generate substantial revenue and achieve profitability, we will need to raise additional capital to fund ongoing operations and capital needs, including the payment of the milestone payments referenced above.
We have based the foregoing estimate on assumptions that may prove to be wrong, and we could use our capital resources sooner than we currently expect. This estimate assumes, among other things, that we do not obtain any additional funding through grants and clinical trial support or through new collaboration arrangements. Our future capital requirements will depend on many factors, including:
•the costs, timing and outcome of clinical trials required for clinical development of ivonescimab;
•the number and development requirements of other future product candidates that we pursue;
•the costs, timing and outcome of regulatory review of ivonescimab and/or our other product candidates we develop;
•the costs and timing of commercialization activities, including product sales, marketing, distribution and manufacturing, for any of our product candidates that receive marketing approval;
•the extent to which we become liable for milestone payments under the License Agreement and Second Amendment for ivonescimab;
•subject to receipt of marketing approval, revenue received from commercial sales of any product candidates;
•the costs and timing of preparing, filing and prosecuting patent applications, maintaining and protecting our intellectual property rights and defending against any intellectual property-related claims;
•our ability to establish and maintain collaborations, licensing or other arrangements and the financial terms of such arrangements;
•the extent to which we acquire or invest in other businesses, products and technologies;
•the rate of the expansion of our physical presence; and
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•the extent to which we change our physical presence.
Until such time, if ever, as we can generate substantial product revenues, we expect to finance our cash needs through a combination of some, or all, of the following: equity and debt offerings, collaborations, strategic alliances, grants and clinical trial support from government entities, philanthropic, non-government and not-for-profit organizations, and marketing, distribution or licensing arrangements.
We will need to seek additional funding in the future to fund operations. Additional capital, when needed, may not be available to us on acceptable terms, or at all. To the extent that we raise additional capital through the sale of equity or convertible debt securities, the ownership interest of our existing stockholders may be diluted, and the terms of these securities may include liquidation or other preferences that adversely affect the rights of our existing stockholders. Additional debt financing, if available, may involve agreements that include covenants limiting or restricting our ability to take specific actions, such as incurring additional debt, making capital expenditures or declaring dividends or other distributions. If we raise additional funds through collaborations, strategic alliances or marketing, distribution, or licensing arrangements with third parties, we may have to relinquish valuable rights to our technologies, future revenue streams, research programs or product candidates or to grant licenses on terms that may not be favorable to us.
If we are unable to raise additional funds through equity or debt financings or other arrangements when needed, we may be required to delay, limit, reduce or terminate our product development or future commercialization efforts or grant rights to develop and market product candidates that we would otherwise prefer to develop and market ourselves, which could materially adversely affect our business, operating results and financial condition and our ability to continue operations.
Cash Flows
The following table summarizes our cash flows for the nine months ended September 30, 2026 and 2025:
| Nine Months Ended September 30, | ||||||||||||||
| (in millions) | 2026 | 2025 | ||||||||||||
| Net cash used in operating activities | $ | (423.2) | $ | (221.0) | ||||||||||
| Net cash provided by investing activities | $ | 18.5 | $ | 310.8 | ||||||||||
| Net cash provided by financing activities | $ | 330.3 | $ | 43.7 | ||||||||||
Operating Activities
Net cash used in operating activities for the nine months ended September 30, 2026 was $423.2 million and primarily consisted of a net loss of $613.5 million, partially offset by non-cash charges of $178.5 million and an $11.8 million net change in operating assets and liabilities. The non-cash charges primarily consisted of $189.2 million of stock-based compensation driven by the modification to outstanding performance-based stock option awards which removed the performance-based vesting criteria, partially offset by $11.1 million relating to amortization of the discount on short-term investments in U.S. government treasury bills. The net change in operating assets and liabilities was primarily due to a $23.4 million increase in accrued liabilities, a $12.7 million increase in accounts payable and a $1.0 million increase in accrued compensation, offset by a $24.1 million increase in prepaid expenses and other current assets and a $1.8 million increase in other assets.
Net cash used in operating activities for the nine months ended September 30, 2025 was $221.0 million and primarily consisted of a net loss of $860.4 million and a $23.1 million net change in working capital, partially offset by non-cash charges of $616.3 million. The non-cash charges primarily consisted of $620.6 million of stock-based compensation driven by the modification to outstanding performance-based stock option awards which removed the performance-based vesting criteria, partially offset by $4.0 million relating to amortization of the discount on short-term investments in U.S. Treasury securities. The net change in working capital was primarily due to a $17.4 million increase in accounts payable, $7.4 million increase in accrued liabilities and a decrease of $3.7 million in prepaid expenses and other current assets, partially offset by an increase of $4.5 million in other assets and a decrease of $1.0 million in accrued compensation.
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Investing Activities
Net cash provided by investing activities for the nine months ended September 30, 2026 was $18.5 million and primarily driven by $672.3 million in maturities and sales of short-term investments, offset by $652.3 million in purchase of short-term investments and $1.6 million in purchases of property and equipment.
Net cash provided by investing activities for the nine months ended September 30, 2025 was $310.8 million and was primarily due to $311.3 million received from maturities of short-term investments in U.S. Treasury securities.
Financing Activities
Net cash provided by financing activities for the nine months ended September 30, 2026 was $330.3 million and was driven by $320.2 million net proceeds from our Distribution Agreement and Second Distribution Agreement and $10.1 million of proceeds received related to employee stock awards and purchase plans.
Net cash provided by financing activities was $43.7 million for the nine months ended September 30, 2025, was due to $31.8 million net proceeds from our Distribution Agreement, $7.3 million of proceeds received related to the exercise of warrants and $4.6 million of proceeds received related to employee stock awards and purchase plans.
Critical Accounting Policies and Significant Judgments and Estimates
Our management’s discussion and analysis of our financial condition and results of operations are based on our unaudited condensed consolidated financial statements, which have been prepared in accordance with U.S. GAAP. The preparation of our financial statements requires us to make estimates and judgments that affect the reported amounts of assets, liabilities, and expenses and the disclosure of contingent liabilities in our financial statements. On an ongoing basis, we evaluate our estimates and judgments, including those related to research and development expenses, stock-based compensation and income taxes. We base our estimates on historical experience, known trends and events, and various other factors that we believe to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results may differ from these estimates under different assumptions or conditions.
Our significant accounting policies are described in Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations, and in Critical Accounting Policies and Significant Judgments and Estimates in our Annual Report. There have been no material changes to our critical accounting policies and estimates that were disclosed in our Annual Report.
Except as set forth in Note 13, Commitments and Contingencies, to our unaudited condensed consolidated financial statements included in this Quarterly Report on Form 10-Q, there have been no material changes from the contractual obligations and commitments as of December 31, 2025 previously disclosed in our Annual Report on Form 10-K filed with the SEC on February 23, 2026.
We did not have during the periods presented, and we do not currently have, any off-balance sheet arrangements, as defined in the rules and regulations of the SEC.
Recently Issued Accounting Pronouncements
For a discussion of recently issued accounting pronouncements, refer to Note 2, Summary of Significant Accounting Policies and Recent Accounting Pronouncements, to our unaudited condensed consolidated financial statements included in this Quarterly Report on Form 10-Q.
Item 3. Quantitative and Qualitative Disclosures About Market Risk.
Our primary exposures to market risk are liquidity risk and foreign currency risk.
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Liquidity Risk
We have funded our operations since inception primarily through the issuance of equity and debt securities. We have also received funding from our license and collaboration arrangements. Until such time as we can generate significant revenue from product sales, if ever, we expect to finance our operations through a combination of public or private equity or debt financings or other sources. Adequate additional financing may not be available to us on acceptable terms, or at all. Our inability to raise capital as and when needed would have a negative impact on our financial condition and our ability to pursue our business strategy.
Foreign Currency Exchange Rate Risk
Foreign currency exchange rate risk refers to the risk that the value of a financial commitment or recognized asset or liability will fluctuate due to changes in foreign currency rates. Our net loss and financial position, as expressed in U.S. dollars, are exposed to movements in foreign exchange rates against the pound sterling and the euro. The main trading currencies are the pound sterling, the U.S. dollar, Japanese Yen, and the euro. We are exposed to foreign currency exchange rate risk as a result of entering into operating transactions denominated in currencies other than the functional currency of our subsidiaries, particularly in relation to our monetary assets and liabilities relating to intercompany transactions, supplier liabilities and the translation of foreign cash balances. Operating transaction foreign currency gains and losses are included in the determination of net loss in our statements of operations and comprehensive loss. We monitor our exposure to foreign currency exchange rate risk. Exposures are generally managed through natural hedging via the currency denomination of cash balances and any impact currently is not material to us.
Interest Rate Risk
We hold our cash, cash equivalents and short-term investments for working capital purposes. Some of the securities we invest in are subject to market risk. This means that a change in prevailing interest rates may cause the principal amount of such investments to fluctuate. To minimize this risk, we maintain our portfolio of cash, cash equivalents and short-term investments which are invested in a variety of short-term securities, including money market funds and investments in U.S. treasury securities. Due to the short-term nature of these instruments, we believe that we do not have any material exposure to changes in the fair value of our investment portfolio as a result of changes in interest rates. Declines in interest rates, however, would reduce future interest income. The effect of a hypothetical 10% increase or decrease in overall interest rates would not have had a material impact on our operating results or the total fair value of our portfolio.
Credit Risk
We consider all of our material counterparties to be creditworthy. We consider the credit risk for each of our counterparties to be low and do not have a significant concentration of credit risk at any of our counterparties. We have $0.5 million of research and development tax credits outstanding at September 30, 2026. Given that these receivables relate to the United Kingdom research and development tax credit cash rebate regimes and given our history of collection, it is highly unlikely that these amounts will not be collected.
Item 4. Controls and Procedures.
We have carried out an evaluation of the effectiveness of our disclosure controls and procedures under the supervision and the participation of the Company’s management, including our Co-Chief Executive Officers (our Principal Executive Officers) and our Chief Operating Officer and Chief Financial Officer (our Principal Financial Officer). The term “disclosure controls and procedures,” as defined in Rules 13a-15(e) and 15d-15(e) under the Exchange Act, means controls and other procedures of a company that are designed to ensure that information required to be disclosed by a company in the reports that it files or submits under the Exchange Act is recorded, processed, summarized and reported within the time periods specified in the SEC’s rules and forms. Disclosure controls and procedures include, without limitation, controls and procedures designed to ensure that information required to be disclosed by a company in the reports that it files or submits under the Exchange Act is accumulated and communicated to the company’s management, including its principal executive and principal financial officers, as appropriate to allow timely decisions regarding required disclosure. There are inherent limitations to the effectiveness of any system of disclosure controls and procedures, including the possibility of human error
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and the circumvention or overriding of the controls and procedures. Accordingly, even effective disclosure controls and procedures can only provide reasonable assurance of achieving their control objectives. Based upon our evaluation of our disclosure controls and procedures as of September 30, 2026, our Co-Chief Executive Officer and Chairman of the Board and our Co-Chief Executive Officer, President and Director (our Principal Executive Officers), and our Chief Operating Officer, Chief Financial Officer and Director (our Principal Financial Officer) concluded that, as of such date, our disclosure controls and procedures were effective at a reasonable level of assurance.
Changes in Internal Control over Financial Reporting
There were no changes in our internal control over financial reporting (as defined in Rules 13a‑15(f) and 15d‑15(f) under the Exchange Act) during the quarter ended September 30, 2026, that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.
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PART II - OTHER INFORMATION
Item 1. Legal Proceedings.
From time to time, we may become involved in legal proceedings arising in the ordinary course of our business. Except as described below, we are not aware of any legal proceedings arising outside the ordinary course of business.
European Patent Opposition
On June 18, 2025, an unknown third party (the “Opponent”) filed a notice of opposition against the Company’s in-licensed EP3882275B1 patent (the “’275 patent”) in the European Opposition Division of the European Patent Office (“EPO”). The ’275 patent covers Ivonescimab. The notice primarily asserts that the ’275 patent lacks inventive step. The Company contests these assertions and worked with its collaboration partner, Akeso, to timely file a response before the European Opposition Division of the EPO on January 2, 2026. The Opponent has filed a reply on March 25, 2026 and Summit and Akeso filed a response to the reply on May 8, 2026. An anonymous Third Party Observation (“TPO”) was filed on June 8, 2026. Summit and Akeso filed a reply on June 22, 2026. Another anonymous TPO was filed on June 24, 2026.
Item 1A. Risk Factors.
An investment in our common stock or other securities involves a number of risks. In addition to other information set forth in this Quarterly Report on Form 10-Q, you should carefully consider each of the risks described in our Annual Report, which includes a detailed discussion of the Company’s risk factors. If any of the risks described therein or other uncertainties currently unknown to us, or that we currently deem to be immaterial, develop into actual events, our business, financial condition, or results of operations could be negatively affected, the market price of our common stock or other securities could decline, and you may lose all or part of your investment.
There have been no material changes to the risk factors disclosed in Item 1A of our Annual Report.
Item 2. Unregistered Sales of Equity Securities and Use of Proceeds.
There were no unregistered sales of equity securities sold during the period covered by this Quarterly Report on Form 10-Q that were not previously included in a Current Report on Form 8-K filed by the Company.
Item 3. Defaults Upon Senior Securities.
None.
Item 4. Mine Safety Disclosures.
None.
Item 5. Other Information.
Subsequent Events.
On November 4, 2026, the Company entered into the 2026 Sublease Agreement with Genius, an affiliate of the Company’s Co-CEO, Robert W. Duggan. Pursuant to the 2026 Genius Sublease Agreement, effective November 1, 2026, the Company sublet from Genius 2,382 square feet of office space in the same facility as the Company’s headquarters in Miami, Florida for a twelve month term for a total rental payment of approximately $205.
10b5-1 Trading Plans.
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Item 6. Exhibits.
Exhibit Index
| Exhibit No. | Description | ||||||||||
| 3.1 | |||||||||||
| 3.2 | |||||||||||
| 3.3 | |||||||||||
| 3.4 | |||||||||||
| 3.5 | |||||||||||
| 3.6 | |||||||||||
| 10.1 | |||||||||||
| 10.2 | |||||||||||
| 10.3+ | |||||||||||
| 10.4*+ | |||||||||||
| 31.1* | |||||||||||
| 31.2* | |||||||||||
| 31.3* | |||||||||||
| 32.1** | |||||||||||
| 101.SCH* | XBRL Taxonomy Extension Schema Document | ||||||||||
| 101.CAL* | XBRL Taxonomy Extension Calculation Linkbase Document | ||||||||||
| 101.DEF* | XBRL Taxonomy Extension Definition Linkbase Document | ||||||||||
| 101.LAB* | XBRL Taxonomy Extension Label Linkbase Document | ||||||||||
| 101.PRE* | XBRL Taxonomy Extension Presentation Linkbase Document | ||||||||||
| 104* | Cover Page Interactive Data File (formatted as Inline XBRL and contained in Exhibit 101) | ||||||||||
* | Filed herewith. | |||||||
| ** | Furnished herewith. | |||||||
| + | Certain of the exhibits and schedules to this exhibit have been omitted in accordance with Regulation S-K Item 601(a)(5). The Company agrees to furnish supplementally a copy of all omitted exhibits and schedules to the SEC upon its request. | |||||||
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SIGNATURES
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, thereunto duly authorized.
Date: November 4, 2026 | SUMMIT THERAPEUTICS INC. | ||||||||||
By: | /s/ Manmeet S. Soni | ||||||||||
Name: | Manmeet S. Soni | ||||||||||
Title | Chief Operating Officer, Chief Financial Officer and Director | ||||||||||
(Principal Financial Officer) | |||||||||||
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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. SUBLEASE THIS SUBLEASE, is entered into effective as of the 1st day of November 2026, by and between GENIUS 24C INC., a Florida corporation, hereinafter called "Sublandlord" and SUMMIT THERAPEUTICS INC., a Delaware corporation having an office and place of business at 601 Brickell Key Drive, Suite 1000, Miami, FL 33131, hereinafter called "Subtenant". WITNESETH: WHEREAS, by a certain written lease agreement dated May 12, 2025 (hereinafter called the "Master Lease"), Brickell Key Centre, LLC (hereinafter called "Owner") leased to Sublandlord those certain premises ("Premises") consisting of 9,527 feet of space (Suite 900) located at and commonly known as 601 Brickell Key Drive, Suite 900, Miami, Florida, which, together with such other improvements and appurtenances therein mentioned, are more particularly described in said Master Lease; and WHEREAS, Subtenant desires to sublease from Sublandlord, and Sublandlord is willing to sublet to Subtenant, a portion of the Premises containing approximately 2,382 square feet of space (hereinafter called the "Sublease Premises"), on the terms and conditions more particularly hereinafter set forth; and WHEREAS, Sublandlord and Subtenant intend that Subtenant shall have the use of the office furniture (the "Personal Property") and amenities on the Premise for the duration of the Term (hereinafter defined). NOW, THEREFORE, in consideration of the mutual covenants, conditions and agreements herein contained, Sublandlord and Subtenant agree as follows: 1. DEMISE• SUBLEASE PREMISES 1.1. Sublandlord, for and in consideration of the rents and covenants specified to be paid, performed and observed by Subtenant, does hereby let, sublet, lease and demise to Subtenant the aforementioned Sublease Premises for the term and according to the covenants and conditions contained herein. 2. TERM 2.1. This Sublease shall be for a term of approximately twelve (12) months (the "Sublease Term") commencing on November 01, 2026 (the "Sublease Commencement Date") and terminating on October 31, 2027 (the "Sublease Expiration Date"). 2.2. Subtenant and Subtenant's representatives may enter the Sublease Premises any time after the execution date of the Sublease Agreement so long as (a) Owner has consented to the Sublease and (b) Subtenant and Subtenant's representatives comply with the terms and conditions of the Sublease including the Insurance requirements provided herein. So long as these conditions are satisfied, Subtenant may, on notice to Sublandlord, have early access to the Sublease Premises for the purposes of assessing and performing installation of telephone, data cabling, etc. ("Prior Access Period"). Subtenant shall not be responsible for payment of Rent or Additional Rent (defined herein) during the Prior
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. Access Period. Subtenant shall not conduct business from the Sublease Premises during the Prior Access Period. 2.3. During the Sublease Term, Subtenant shall have the right to access and use building amenities, including, but not limited to, any exercise areas and cafeteria, if any, in the manner provided in the Master Lease. 3. RENT 3.1. Subtenant shall pay to Sublandlord as rent for said Sublease Premises as follows: Period Base Rent per Rentable Square Foot Monthly Base Rent 11/1/26-4/30/27 [**] [**] 5/1/27-5/31/27 [**] [**]* 6/1/27-10/31/27 [**] [**] *Monthly Base Rent abated in accordance with the Master Lease Monthly Base Rent is due on the first day of the calendar month. 3.2. In addition, Subtenant shall promptly pay to Sublandlord, Additional Rent, as defined in Section 6 of Master Lease, if applicable, based upon Operating Expenses or Taxes during any Operating Period exceeding Base Operating Expenses or Base Taxes, respectively. Subtenant shall pay Sublandlord Additional Rent within ten (10) days of receipt of such accounting of costs equal to [**] of Sublandlord Operating Expenses or Taxes billed as per Master Lease. Sublandlord to supply all invoices and receipts of costs incurred upon request of Subtenant. 3.3. In addition to the Rent and Additional Rent, Subtenant shall promptly pay to Sublandlord (i) any amounts due as a result of Subtenant's requests, including, but not limited to costs incurred for after hours HVAC use pursuant to the terms of the Master Lease (ii) proportionate amount (equal to [**] of Sublandlord costs) of Sublandlord's cable, internet and phone cost and office supplies (if Subtenant uses Sublandlord's services); (iii) any amounts due for use of parking spaces; and (iv) any amount due to compensate Sublandlord for damages resulting from the negligent or willful misconduct of Subtenant ("Additional Costs"). To the extent reasonably possible, Sublandlord shall notify Subtenant of any upcoming Additional Costs in advance and shall supply all invoices and receipts of costs incurred upon request of Subtenant. 3.4. Payment of said Sublease Rent, Additional Rent and Additional Costs shall be made to Sublandlord at the following address or at such other place as Sublandlord may designate in writing, without any offset or deduction whatsoever. Rent Payment Address:
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. GENIUS 24C INC. 601 Brickell Key Drive, Suite 900 Miami, FL 33131 Attn: [**] 4. INCORPORATION OF MASTER LEASE 4.1. The provisions of the Master Lease are, except as otherwise herein specifically provided, hereby incorporated in this Sublease with the same effect as if entirely rewritten herein, and shall fix the rights and obligations of the parties hereto with respect to the Sublease Premises with the same effect as if Sublandlord and Subtenant were, respectively, the landlord and tenant named in the Master Lease. Subtenant hereby covenants to perform the covenants and undertakings of Sublandlord as tenant under the Master Lease to the extent the same are applicable to the Sublease Premises during the term of this Sublease, and agrees not to do or permit to be done any act which shall result in a violation of any of the terms and conditions of said Master Lease. Except as otherwise specifically provided herein, Sublandlord is to have the benefit of the covenants and undertakings of Owner as landlord in the Master Lease to the extent the same are applicable to the Sublease Premises during the term of this Sublease. It is expressly understood and agreed, however, that Sublandlord is not in the position to render any of the services or to perform any of the obligations required of Sublandlord by the terms of this Sublease, and that performance by Sublandlord of its obligations hereunder are conditioned upon due performance by Owner of its corresponding obligations under the Master Lease. It is further understood and agreed, therefore, that notwithstanding anything to the contrary contained in this Sublease, Sublandlord shall not be in default under this Sublease for failure to render such services or perform such obligations required of Sublandlord by the terms of this Sublease which are the responsibility of the Owner as landlord under the Master Lease: but Sublandlord agrees to take all reasonable measures to insure that Owner performs said obligations. The term "reasonable measures" shall include measures that it would reasonably take in its own behalf but shall not include legal action against Owner for its failure to so perform unless Subtenant agrees to pay proportionate amount (equal to [**] of Sublandlord costs) in connection therewith. 5. HOLDING OVER 5.1. Any holding over by Subtenant beyond the expiration date of this Sublease shall be deemed unlawful unless expressly consented to by Sublandlord in writing, and Sublandlord shall be entitled to any and all remedies in law or in equity by reason of such unlawful holding over by Subtenant. Subtenant agrees to indemnify and save Sublandlord harmless against and from any and all loss, cost, expense and liability incurred by Sublandlord under the Master Lease which incurred solely in relation to this Sublease Agreement and under applicable law, whether at law or in equity, by reason of any such holding over.
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. 6. NOTICES 6.1. All notices, requests, demands and other communications with respect to this Sublease, whether or not herein expressly provided for, shall be in writing and shall be deemed to have been duly given the next business day after being deposited (in time for delivery by such service on such business day) with a national or international courier service and via email, for delivery to the parties at the following addresses (which such addresses may be changed by either party by giving written notice thereof to the other): If to Sublandlord: At the Sublease Premises Attn: [**] Email: [**] If to Subtenant: Summit Therapeutics Inc. 601 Brickell Key Drive, Suite 1000 Miami, FL 33131 Attn: [**] Email: [**] 7. SUBLEASE SUBORDINATE TO MASTER LEASE 7.1. This Sublease is subject and subordinate in all respects to said Master Lease. Subtenant acknowledges that it has received a copy of said Master Lease. 8. ASSIGNMENT AND SUBLETTING 8.1. Subtenant shall not assign this Sublease, nor suffer or permit it to be assigned by operation of law or otherwise, nor shall the Subtenant let, sublet or underlet or permit the said Sublease Premises or any pan thereof to be used or occupied by others without the written consent of Sublandlord, such consent not to be unreasonably withheld and further subject to Owner prior written consent. 9. CONDITION- USE OF FURNITURE 9.1. Subtenant acknowledges that it has inspected the Sublease Premises demised hereunder and is fully satisfied with their condition and accepts the same, "as is". Sublandlord has made no representation or warranties of any nature whatsoever with regard to the Sublease Premises, other than those set forth herein, and Sublandlord shall have no obligation or duty with regard to preparation of the Sublease Premises for occupancy by Subtenant. 9.2. Subtenant further acknowledges that it shall be, at Subtenant's sole cost and expense (equal to [**] of Sublandlord cost and expense), responsible for all restoration requirements to the extent required by the Master Lease and this Sublease at the end of the Sublease Term.
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. 9.3. Subtenant shall have the use of all furniture present in the Sublease Premises ("Furniture") during the Term at no additional charge. Sublandlord makes no representations or warranties with respect to the condition of the Furniture and Subtenant accepts the use of the Furniture in its "as is" condition. Subtenant shall be responsible for replacing any Furniture that is broken or destroyed by Subtenant, subject to normal wear and tear. 10. BROKERS 10.1. Sublandlord and Subtenant each represent and warrant to the other that it has had no dealings with any real estate broker or agent in connection with the negotiation of this Sublease, and that they know of no other real estate broker or agent who is or might be entitled to a commission in connection with this Sublease. 11. INDEMNITY 11.1. Subtenant shall defend, indemnify and save harmless Sublandlord against and from any and all liability, damage, expense, cause of action, suits, claims or judgments for injury or death to persons or damage to property sustained by anyone in, on or about said Sublease Premises or any part thereof, arising out of or in any way connected with Subtenant's use or occupation of the Sublease Premises or this Sublease, including without limitation any breach or violation of Section 12 below. 12. HAZARDOUS SUBSTANCES 12.1. Subtenant shall not cause or permit any "Hazardous Substances" (as hereinafter defined) to be used, stored, generated or disposed of in, on or about the Sublease Premises by Subtenant, its agents, employees, contractors or invitees, except for such Hazardous Substances as are normally utilized in the activities which are permitted on the Sublease Premises pursuant to the Master Lease and this Sublease and which are necessary to Subtenant's business. Any such Hazardous Substances permitted on the Sublease Premises as hereinabove provided, and all containers therefor, shall be used, kept, stored and disposed of in a manner that complies with all federal, state and local laws or regulations applicable to any such Hazardous Substances. Subtenant shall defend, indemnify and hold harmless Sublandlord from any and all claims, damages, fines, judgments, penalties, costs, expenses or liabilities (including, without limitation, any and all sums paid for settlement of claims, attorneys' fees, consultant and expert fees) arising during or after the Sublease term from or in connection with the use, storage, generation or disposal of Hazardous Substances in, on or about the Sublease Premises by Subtenant, Subtenant's agents, employees, contractors or invitees. As used herein, "Hazardous Substances" means any substance with is toxic, ignitable, reactive, or corrosive and which is regulated by any state or local government or by the United States government. "Hazardous Substances" includes any and all material or substances which are defined as "hazardous waste", "extremely hazardous waste" or a "hazardous substance" pursuant to state, federal or local governmental law. "Hazardous Substances" includes but is not restricted to asbestos, polychlorinated biphenyls ("PCBs") and petroleum products.
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. 13. SIGNAGE 13.1. Subtenant shall have the right, at Subtenant sole cost and expense and subject to the written approval of Owner, to furnish Subtenant leased name on a wall within the Subleased Premises. 14. PARKING 14.1. Available, parking in the Building’s Parking Facility at a ratio of 2.6 parking spaces per one thousand (1,000) rentable square feet of the Premises (the “Parking Ratio”), on an unreserved basis in common with other tenants of the Building, in locations as determined by Landlord, at the current rate of [**] per unreserved space, per month, plus applicable sales tax and surcharges, with such rate subject to increase from time to time as determined by Landlord. As a part of the aforementioned Parking Ratio, Subtenant shall have the right to up to six (6) unreserved parking spaces within the Parking Facility calculated as 2,382 sq ft/1,000 Rentable Square Feet times 2.6 parking spaces which equals to 6.19 parking spaces, in locations reasonably determined by Landlord, at the current rate of [**] per unreserved space, per month, plus applicable sales tax and surcharges, with such rate subject to increase from time to time as determined by Landlord. 15. MISCELLANEOUS 15.1. This Agreement: 15.1.1. Contains the entire agreement among the parties hereto with respect to the subject matter covered hereby; 15.1.2. May not be amended or rescinded except by an instrument in writing executed by each of the parties hereto; 15.1.3. Shall inure to the benefit of and be binding upon the successors and permitted assigns of the parties hereto. 15.1.4. The cure periods provided for in the Master Lease between Sublandlord and Owner shall be applicable to the Parties in this Sublease. 16. CONSENT BY OWNER 16.1. This Sublease has been approved in writing by Owner [REMAINDER OF PAGE INTENTIONALLY BLANK. SIGNATURE PAGE FOLLOWS]
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. IN WITNESS WHEREOF, the parties have hereunto set their hands and seals to be effective as of the day and year first above written. Sublandlord: GENIUS 24C INC. By: /s/ Bob Duggan Name: Bob Duggan Title: CEO Date: November 4, 2026 Subtenant: SUMMIT THERAPEUTICS INC. By: /s/ Bhaskar Anand Name: Bhaskar Anand Title: CAO Date: November 4, 2026
EXHIBIT 31.1
CERTIFICATION OF PRINCIPAL EXECUTIVE OFFICER
PURSUANT TO RULES 13a-14(a) AND 15d-14(a)
OF THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED
I, Robert W. Duggan, certify that:
1.I have reviewed this Quarterly Report on Form 10-Q for the quarter ended September 30, 2026 of Summit Therapeutics Inc. (the "Registrant");
2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;
3.Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the Registrant as of, and for, the periods presented in this report;
4.The Registrant’s other certifying officers and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the Registrant and have:
a.Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the Registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;
b.Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;
c.Evaluated the effectiveness of the Registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and
d.Disclosed in this report any change in the Registrant’s internal control over financial reporting that occurred during the Registrant's most recent fiscal quarter (the Registrant's fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the Registrant’s internal control over financial reporting; and
5.The Registrant’s other certifying officers and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the Registrant’s auditors and the audit committee of the Registrant’s board of directors (or persons performing the equivalent functions):
a.All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the Registrant’s ability to record, process, summarize and report financial information; and
b.Any fraud, whether or not material, that involves management or other employees who have a significant role in the Registrant’s internal control over financial reporting.
Date: November 4, 2026
| By: | /s/ Robert W. Duggan | |||||||
| Name: | Robert W. Duggan | |||||||
| Title: | Co-Chief Executive Officer and Chairman of the Board of Directors | |||||||
| (Principal Executive Officer) | ||||||||
EXHIBIT 31.2
CERTIFICATION OF PRINCIPAL EXECUTIVE OFFICER
PURSUANT TO RULES 13a-14(a) AND 15d-14(a)
OF THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED
I, Dr. Mahkam Zanganeh, certify that:
1.I have reviewed this Quarterly Report on Form 10-Q for the quarter ended September 30, 2026 of Summit Therapeutics Inc.(the "Registrant");
2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;
3.Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the Registrant as of, and for, the periods presented in this report;
4.The Registrant’s other certifying officers and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the Registrant and have:
a.Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the Registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;
b.Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;
c.Evaluated the effectiveness of the Registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and
d.Disclosed in this report any change in the Registrant’s internal control over financial reporting that occurred during the Registrant's most recent fiscal quarter (the Registrant's fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the Registrant’s internal control over financial reporting; and
5.The Registrant’s other certifying officers and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the Registrant’s auditors and the audit committee of the Registrant’s board of directors (or persons performing the equivalent functions):
a.All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the Registrant’s ability to record, process, summarize and report financial information; and
b.Any fraud, whether or not material, that involves management or other employees who have a significant role in the Registrant’s internal control over financial reporting.
Date: November 4, 2026
| By: | /s/ Mahkam Zanganeh | |||||||
| Name: | Dr. Mahkam Zanganeh | |||||||
| Title: | Co-Chief Executive Officer, President and Director | |||||||
| (Principal Executive Officer) | ||||||||
EXHIBIT 31.3
CERTIFICATION OF PRINCIPAL FINANCIAL OFFICER
PURSUANT TO RULES 13a-14(a) AND 15d-14(a)
OF THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED
I, Manmeet Soni, certify that:
1.I have reviewed this Quarterly Report on Form 10-Q for the quarter ended September 30, 2026 of Summit Therapeutics Inc. (the "Registrant");
2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;
3.Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the Registrant as of, and for, the periods presented in this report;
4.The Registrant’s other certifying officers and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the Registrant and have:
a.Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the Registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;
b.Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;
c.Evaluated the effectiveness of the Registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and
d.Disclosed in this report any change in the Registrant’s internal control over financial reporting that occurred during the Registrant's most recent fiscal quarter (the Registrant's fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the Registrant’s internal control over financial reporting; and
5.The Registrant’s other certifying officers and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the Registrant’s auditors and the audit committee of the Registrant’s board of directors (or persons performing the equivalent functions):
a.All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the Registrant’s ability to record, process, summarize and report financial information; and
b.Any fraud, whether or not material, that involves management or other employees who have a significant role in the Registrant’s internal control over financial reporting.
Date: November 4, 2026
| By: | /s/ Manmeet S. Soni | |||||||
| Name: | Manmeet S. Soni | |||||||
| Title: | Chief Operating Officer, Chief Financial Officer and Director | |||||||
| (Principal Financial Officer) | ||||||||
EXHIBIT 32.1
CERTIFICATION OF PRINCIPAL EXECUTIVE OFFICERS AND PRINCIPAL FINANCIAL OFFICER PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO
SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002
In connection with the Quarterly Report on Form 10-Q of Summit Therapeutics Inc. (the “Company”) for the quarter ended September 30, 2026, as filed with the U.S. Securities and Exchange Commission on the date hereof (the “Report”), each of the undersigned officers does hereby certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:
1.The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and
2.The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.
Date: November 4, 2026 | ||||||||
| By: | /s/ Robert W. Duggan | |||||||
| Name: | Robert W. Duggan | |||||||
| Title: | Co-Chief Executive Officer and Chairman of the Board of Directors | |||||||
| (Principal Executive Officer) | ||||||||
Date: November 4, 2026 | ||||||||
| By: | /s/ Mahkam Zanganeh | |||||||
| Name: | Dr. Mahkam Zanganeh | |||||||
| Title: | Co-Chief Executive Officer, President and Director | |||||||
| (Principal Executive Officer) | ||||||||
Date: November 4, 2026 | ||||||||
| By: | /s/ Manmeet S. Soni | |||||||
| Name: | Manmeet S. Soni | |||||||
| Title: | Chief Operating Officer, Chief Financial Officer and Director | |||||||
| (Principal Financial Officer) | ||||||||