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

The following discussion and analysis of our financial condition and results of operations is for the year ended December 31, 2024 compared with the year ended December 31, 2023. This comparison should be read in conjunction with our consolidated financial statements and related notes appearing elsewhere in this Annual Report on Form 10-K. This discussion contains forward-looking statements based upon current expectations that involve risks and uncertainties. Our actual results may differ materially from those anticipated in these forward-looking statements as a result of various factors, including those set forth under “Risk Factors” included in Part I, Item 1A or in other parts of this Annual Report on Form 10-K. For a discussion and analysis of our financial condition and results of operations for the year ended December 31, 2023 compared to December 31, 2022, see Part II, Item 7, “Management’s Discussion and Analysis of Financial Condition and Results of Operations” included in the 2023 Annual Report on Form 10-K, filed with the Securities and Exchange Commission on February 20, 2024.

The Management’s Discussion and Analysis of Financial Condition and Results of Operations, or MD&A, describes principal factors affecting the results of our operations, financial condition and liquidity, as well as our critical accounting policies and estimates that require significant judgment and thus have the most significant potential impact on our Consolidated Financial Statements. This section provides an analysis of our financial results for the year ended December 31, 2024 compared to the same period in the prior year.

Company Overview

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

The Company's current lead development candidate is ivonescimab, a novel, potential first-in-class bispecific antibody intending to combine the effects of immunotherapy via a blockade of PD-1 with the anti-angiogenesis effects of an anti-VEGF compound into a single molecule. On December 5, 2022, the Company entered into a Collaboration and License Agreement (the “License Agreement”) with Akeso, Inc. and its affiliates (collectively, “Akeso”) pursuant to which the Company has in-licensed intellectual property related to ivonescimab. 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 with Akeso to expand its territories covered under the License Agreement to also include the Latin America, Middle East and Africa regions (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.

The Company has begun its development for ivonescimab in non-small cell lung cancer (“NSCLC”), specifically launching 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 have progressed after treatment with a third-generation EGFR tyrosine kinase inhibitor (“TKI”) (“HARMONi”); and

(b) ivonescimab combined with chemotherapy in first-line metastatic NSCLC patients (“HARMONi-3”)

In addition, the Company has begun to activate clinical trial sites in the United States for a Phase III clinical study in the following proposed indication:

In October 2024, the Company completed enrollment in its HARMONi clinical trial. The Company expects to disclose topline results from HARMONi in mid-2025, depending upon maturation of the data per the protocol.

Key Components of our Results of Operations

Operating expenses

The majority of our operating expenses since inception have consisted of research and development activities and general and administrative costs.

Research and Development and Acquired in-process research and development Expenses

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

These include:

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

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

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

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

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

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

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

General and administrative expenses

General and administrative expenses consist primarily of salaries and benefits related to our executive, finance, business development, human resources, legal and other support functions. Other general and administrative expenses include stock-

based compensation expenses, market research costs, facility-related costs, consulting costs and expenses associated with the requirements of being a publicly traded company in the United States, including insurance, legal, audit and taxation services fees.

We anticipate that our general and administrative expenses will continue to increase in the future as we increase our headcount to support our planned clinical trials of ivonescimab, continued research and development and potential commercialization of our product candidates. We also anticipate continued accounting, audit, regulatory, compliance, insurance and investor and public relations expenses associated with being a publicly traded company in the United States.

Other operating (expense) income, net

Other operating (expense) income, net consists primarily of research and development ("R&D") tax credits received in the United Kingdom (“U.K.”). We benefit from two U.K. research and development tax credit cash rebate regimes: Small and Medium Enterprise Program (“SME Program”) and the Research and Development Expenditure Credit Program (“RDEC Program”). Under both schemes, we receive cash payments that are not dependent on our pre-tax net income levels.

Based on criteria established by His Majesty’s Revenue and Customs (“HMRC”), a portion of expenditures being carried out in relation to our pipeline research and development, clinical trials management and third-party manufacturing development activities are eligible for the SME regime tax credits and amounts recognized from grants and clinical trial support from government entities, philanthropic, non-government and not-for-profit organizations.

Other income, net

Other expense, net primarily consists of foreign currency net gains and losses and investment income related to investments in money market funds and U.S. treasury securities. All highly liquid investments with a maturity date of 90 days or less at the date of purchase are considered to be cash equivalents and the related investment income is recognized in net loss. The appropriate classification of investments in securities is determined by the Company at the time of purchase.

Interest expense

Interest expense consists of cash and imputed interest expense incurred related to our promissory notes to related parties. Imputed interest is calculated as the difference between the expected interest payable and the deemed market rate of interest and is recorded as a debt discount at inception of the note payable with a credit to additional paid-in capital for notes payable to related parties. The debt discount is amortized to interest expense using an effective interest rate method.

Taxation

As a U.S. tax resident trading entity, we are subject to U.S. corporate taxation. Our U.K. resident trading subsidiaries are individually subject to U.K. corporate taxation. Due to the nature of our business, we have generated losses since inception. We have recorded a full valuation allowance against the deferred tax assets with respect to these tax losses in excess of our deferred tax liabilities in each jurisdiction because we do not consider it more likely than not that there will be suitable taxable profits in the foreseeable future based on the evidence available against which to offset these losses.

Results of Operations

For a discussion and analysis of our financial condition and results of operations for the year ended December 31, 2023 compared to December 31, 2022, please refer to Item 7 of Part II, “Management’s Discussion and Analysis of Financial Condition and Results of Operations” in our Annual Report on Form 10-K for the year ended December 31, 2023, which was

filed with the SEC on February 20, 2024, and is available on the SEC's website at www.sec.gov and our Investor Relations website at www.smmttx.com/investor-information.

Amounts reported in millions within this Annual Report on Form 10-K 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.

Comparison of the Year Ended December 31, 2024 to the Year Ended December 31, 2023

(in millions) Year Ended December 31,

Operating expenses:

Acquired in-process research and development 15.0 520.9 (505.9)

Other operating income, net 0.3 1.0 (0.7)

Operating Expenses

Research and Development and Acquired in-process research and development Expenses

The table below summarizes our research and development and acquired in-process research and development expenses by category for the year ended December 31, 2024 and 2023, respectively.

(in millions) Year Ended December 31,

Oncology clinical trial related costs $ 100.9 $ 35.2 $ 65.7

Acquired in-process research and development 15.0 520.9 (505.9)

Compensation related costs, excluding stock-based compensation 33.6 21.3 12.3

(1)Anti-infectives includes the Company’s antibiotic pipeline research activities and ridinilazole or CDI program activities (collectively, “Anti-infectives).

The entry into the License Agreement with Akeso, Inc., effective in January 2023, represents a significant change in our strategy from anti-infectives to the therapeutic area of oncology. We invested our resources in the clinical development of ivonescimab during the years ended December 31, 2024 and 2023.

Oncology clinical trial related costs represent our investment in the clinical development of ivonescimab, known as SMT112 in the Licensed Territory.

Research and development expenses (excluding acquired in progress research and development noted below) increased by $91.4 million during the year ended December 31, 2024, compared to the same period in the prior year. This increase was primarily due to our continued investment in oncology clinical trial related costs for ivonescimab, known as SMT112 in the Licensed Territory, resulting in an increase of $65.7 million and an increase in compensation and stock-based compensation related expenses of $23.9 million in the year ended December 31, 2024, to support the clinical development of ivonescimab as we continue to hire additional clinical resources in the oncology field, coupled with acceleration charges related to the achievement of certain market conditions on performance stock option awards. We expect oncology-related research and development costs to continue to increase as we progress with the development of ivonescimab.

In June 2024, we entered into a second amendment (the "Second Amendment") to the License Agreement with Akeso to expand the Licensed Territory to include Latin America, Middle East and Africa regions. Considered an extension of the original License Agreement, we agreed to make an upfront payment to Akeso in the amount of $15.0 million for these expanded territories which we paid in the third quarter of 2024. This was recorded in our consolidated statement of operations and comprehensive loss as acquired in process research and development expenses for the year ended December 31, 2024.

Our investment in ivonescimab included $520.9 million for the year ended December 31, 2023 related to our upfront milestone payments pursuant to the License Agreement with Akeso. The License Agreement closed in January 2023, and both Akeso and Summit entered into the Common Stock Issuance Agreement (“Issuance Agreement”). Pursuant to the License Agreement and Issuance Agreement, Akeso elected to receive 10 million shares of our common stock in lieu of $25.1 million cash and was paid $274.9 million in cash as the initial upfront payment. The remaining $200.0 million upfront payment was paid on March 6, 2023. Acquired in-process research and development expense comprised of the $474.9 million paid in cash, the fair value of the 10 million shares of common stock on the date of closing the transaction of $45.9 million, and $0.1 million of direct transactions costs incurred.

General and Administrative Expenses

The table below summarizes our general and administrative expenses by category for the year ended December 31, 2024 and 2023, respectively.

(in millions) Year Ended December 31,

Legal fees and professional services 4.8 6.9 (2.1)

Other general and administrative expenses 6.0 3.6 2.4

General and administrative expenses increased by $30.2 million for the year ended December 31, 2024, compared to the same period in the prior year, primarily due to an increase of $25.3 million in stock-based compensation related to an increase in equity award grants and the acceleration charges related to the achievement of certain market conditions on performance stock option awards. Additionally, compensation-related costs, excluding stock-based compensation increased by $4.6 million, for the year ended December 31, 2024, compared to the same period in the prior year, as the Company is focused on building its executive management team to continue supporting its growth. We expect general and administrative expenses to continue to increase as we scale our infrastructure and management to support development of ivonescimab.

Other Operating (Expense) Income, net

The table below summarizes our other operating (expense) income by category for the year ended December 31, 2024 and 2023, respectively:

(in millions) Year Ended December 31,

Research and development tax credits $ 0.3 $ 1.0 $ (0.7)

U.K. research and development tax credits decreased by $0.7 million for the year ended December 31, 2024, compared to the same period in the prior year, as management updated its estimates for qualifying expenditures relating to ivonescimab, which resulted in a decrease in tax credits claimed.

Other Income (Expense), Net

The table below summarizes our other income (expense), net by category for the year ended December 31, 2024 and 2023, respectively.

(in millions) Year Ended December 31,

Foreign currency (losses) gains $ (0.1) $ 0.6 $ (0.7)

Reclassification of cumulative currency translation gain — 0.4 (0.4)

Other expense, net — (0.3) 0.3

Other income (expense), net increased by $2.2 million for the year ended December 31, 2024, compared to the same period in the prior year, primarily due to an increase of $3.0 million in interest income due to the higher short-term investments balance, partially offset by unfavorable changes in foreign currency losses of $0.7 million.

Interest Expense

Interest expense on promissory notes payable to related parties decreased to $8.7 million for the year ending December 31, 2024, from $16.5 million during the year ending December 31, 2023, due to full payment of promissory note in October 2024.

Liquidity and Capital Resources

Sources of Liquidity

To date, we have financed our operations primarily through issuances of our common stock, including our most recent private placement issued in September 2024 for gross proceeds of $235.0 million and the raise of $44.2 million gross proceeds from our ATM Agreement during 2024, issuance of debt, and receipt of payments to us under license and collaboration arrangements.

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 the Licensed Territory;

•conduct research and continue development of additional product candidates;

•maintain and augment our intellectual property portfolio and opportunistically acquire complimentary 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 year ended December 31, 2024, we incurred a net loss of $221.3 million, and cash flows used in operating activities was $142.1 million. As of December 31, 2024 we had an accumulated deficit of $1,214.6 million, cash and cash equivalents and short-term investments in U.S. treasury securities of $412.3 million. We expect to continue to generate operating losses for the foreseeable future.

We have evaluated whether our cash, cash equivalents and short-term investments provide sufficient cash to fund our operating cash needs for the next 12 months from the date of issuance of these annual financials. We concluded that our cash, cash equivalents and short-term investments as of December 31, 2024 will fund our operating cash needs for at least the next 12 months from the date of issuance of these financial statements.

From time to time, we may raise additional equity or debt capital through both registered offerings off of a shelf registration, including “at-the-market” 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, depositary 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 at-the-market offering program with J.P. Morgan Securities LLC, as sales agent, in the amount of up to $90 million, of which $45.8 million remains available for sale as of December 31, 2024. If we require or elect to seek additional capital through debt or equity financing in the future, we may not be able to raise capital on terms acceptable to us or at all. To the extent we raise additional capital through the sale of equity or convertible debt securities, the issuance of such securities will result in dilution to our stockholders. If we are required and unable to raise additional capital when desired, our business, operating results and financial condition may be adversely affected. As of the date of this report, additional capital has not been secured.

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

•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 prospects or our ability to continue operations.

Cash Flows

The following table summarizes the results of our cash flows for the years ended December 31, 2024 and 2023.

(in millions) Year Ended December 31,

Net cash used in operating activities $ (142.1) $ (76.8)

Net cash used in investing activities $ (205.3) $ (587.8)

Net cash provided by financing activities $ 381.2 $ 86.5

Operating Activities

Net cash used in operating activities for the year ended December 31, 2024 was $142.1 million and primarily resulted from a net loss of $221.3 million, which included an adjustment of $15.0 million in cash payments related to investing activities for the purchase of in-process research and development from Akeso under the terms of the License Agreement and the associated direct transaction costs, non-cash charges of $48.7 million and a net increase in working capital of $15.5 million. Non-cash charges primarily include $51.0 million of stock-based compensation, partially offset by $2.6 million related to the amortization of discount on short-term investments. The net increase in working capital is primarily due to an $11.9 million increase in accrued liabilities and other current liabilities, a $6.6 million increase in accrued compensation, a $2.5 million decrease in other assets, and a $2.0 million increase in accounts payable, partially offset by a $7.9 million increase in prepaid expenses and other current assets.

Net cash used in operating activities for the year ended December 31, 2023 was $76.8 million and resulted from a net loss of $614.9 million, which included an adjustment of $475.0 million in cash payments related to investing activities for the purchase of in-process research and development from Akeso under the terms of the License Agreement and the associated direct transaction costs and non-cash charges of $63.6 million and a net decrease in working capital of $0.5 million. Non-cash charges primarily include a $45.9 million expense for the issuance of shares in lieu of cash for the Akeso upfront payment, $14.1 million of stock-based compensation, $6.3 million related to non-cash interest expense, and a $0.5 million impairment charge, partially offset by $1.9 million related to amortization of discount on short-term investments and $0.8 million in a net unrealized foreign exchange gain. The net increase in working capital is primarily due to a $3.7 million increase in other long-term assets, a $2.4 million decrease in accrued liabilities, and a $0.4 million decrease in lease liabilities, partially offset by a $4.2 million decrease in the research and development tax credit receivable and a $2.3 million increase in accounts payable.

Investing Activities

Net cash used in investing activities for the years ended December 31, 2024 was $205.3 million and was primarily due to $190.2 million of net purchases of short-term investments and $15.0 million of cash payments made to Akeso pursuant to the License Agreement. Net cash used in investing activities for the years ended December 31, 2023 was $587.8 million and was primarily due to $475.0 million of cash payments made to Akeso pursuant to the License Agreement and $112.9 million of net purchases of short-term investments.

Financing Activities

Net cash provided by financing activities for the year ended December 31, 2024 was $381.2 million and was primarily due to $434.9 million of proceeds from various private placements, $43.0 million net proceeds from our current ATM Agreement, and proceeds received of $2.7 million related to employee stock awards, partially offset by a $100.0 million early principal payment on promissory notes payable to a related party.

Net cash provided by financing activities for the year ended December 31, 2023 was $86.5 million and was primarily due to net proceeds received of $104.1 million (net of paid issuance costs) related to the issuance of common stock from the 2023 Rights Offering and net of the extinguishment of $395.3 million of principal and accrued interest due and payable by us under the $400 million Duggan Promissory Note in satisfaction of the subscription price for the shares subscribed by Mr. Duggan in the 2023 Rights Offering, $5.0 million received for the issuance of common stock via a private placement to a related party, and $1.2 million received for the exercise of stock option warrants, partially offset by the repayment of $24.7 million related to promissory notes from related parties.

Contractual Obligations and Commitments

Fixed asset purchase commitments

At December 31, 2024 and 2023, we had no capital commitments.

Lease commitments

The following table summarizes our lease contractual obligations as of December 31, 2024:

Payment due by period

Operating lease obligations $ 8.0 $ 3.8 $ 2.8 $ 1.4 $ —

Debt commitments

On December 6, 2022, we entered into a Note Purchase Agreement (the “Note Purchase Agreement”), with Mr. Duggan and Dr. Zanganeh, pursuant to which we agreed to sell to each of Mr. Duggan and Dr. Zanganeh unsecured promissory notes in the aggregate amount of $520 million. Pursuant to the Note Purchase Agreement, we issued to Mr. Duggan and Dr. Zanganeh unsecured promissory notes in the amount of $400 million (the “Duggan February Note”) and $20 million (the “Zanganeh Note”), respectively, which matured and became due on February 15, 2023 and an unsecured promissory note to Mr. Duggan in the amount of $100 million (the “Duggan September Note” and together with the Duggan February Note and the Zanganeh Note, the “December 2022 Notes”), which was originally due on September 15, 2023. The maturity dates of the December 2022 Notes could have been extended one or more times at our election, but in no event to a date later than September 6, 2024. In addition, if we consummated a public offering, then upon the later to occur of (i) five business days after we receive the net cash proceeds therefrom or (ii) May 15, 2023, the Duggan February Note and the Zanganeh Note were to be prepaid by an amount equal to the lesser of (a) 100% of the amount of the net proceeds of such offering and (b) the outstanding principal amount on such Notes. On January 19, 2023, we provided notice to extend the term of the Duggan February Note and Duggan September Note to a maturity date of September 6, 2024.

Furthermore, on January 19, 2023, we and Mr. Duggan rectified the Duggan February Note and Duggan September Note in order to correctly reflect the parties’ intent that we may only prepay (i) the Duggan February Note following the completion of a public rights offering to be conducted by us in the approximate amount of $500 million, or a similar capital raise, in an amount equal to the lesser of (x) the net proceeds of the Rights Offering or such capital raise or (y) the full amount outstanding of the Duggan February Note, and (ii) the Duggan September Note following the completion of a capital raising transaction subsequent to the 2023 Rights Offering (as defined in Note 17 Stockholders’ Equity to the consolidated financial statements included under Item 15 Exhibits, Financial Statement Schedules) in an amount equal to the lesser of (A) the net proceeds of such capital raise or (B) the full amount outstanding of the Duggan September Note. Following the issuance of the two new Promissory Notes (the “Duggan Promissory Notes”), the Duggan February Note and Duggan September Note were marked as “cancelled” on their face and replaced in their entirety by the Duggan Promissory Notes (together with the Zanganeh Note, the “Notes”). The Notes accrued interest at an initial rate of 7.5%. All interest on the Notes was paid on the date of signing for the

period through February 15, 2023. Such prepaid interest was paid in a number of shares of our common stock, par value $0.01 (“Common Stock”) equal to the dollar amount of such prepaid interest, divided by $0.7913 (the consolidated closing bid price immediately preceding the time we entered into the Note Purchase Agreement, plus $.01), which was 9,720,291 shares. For all applicable periods following February 15, 2023, interest accrued on the outstanding principal balance of the Notes at the US prime interest rate, as reported in the Wall Street Journal, plus 50 basis points, as adjusted monthly, for three months immediately following February 15, 2023, and thereafter at the US prime rate plus 300 basis points, as adjusted monthly. Accrued interest was paid in cash, quarterly in arrears, on each of March 31, June 30, September 30 and December 31.

On February 15, 2023, the $20 million Zanganeh Note matured and we repaid the outstanding principal balance. In connection with the closing of the Rights Offering, the $400 million Duggan Promissory Note matured and became due, and we satisfied all principal and accrued interest thereunder using a combination of a portion of the cash proceeds from the 2023 Rights Offering and the extinguishment of a portion of the amount due equal to the subscription price of shares subscribed by Mr. Duggan in the 2023 Rights Offering.

On February 17, 2024 the Duggan February Note was amended to extend the maturity date from September 6, 2024 to April 1, 2025. For all applicable periods commencing February 17, 2024, interest accrued on the outstanding principal balance at the greater of 12% or the US prime interest rate, as reported in the Wall Street Journal plus 350 basis points, as adjusted monthly, compounded quarterly. Interest was paid upon maturity of the loan.

As of October 1, 2024, the Company repaid the Duggan September Note in full, resulting in principal payments in the aggregate amount of $100.0 million and accrued cash interest of $7.3 million.

Other commitments

We enter 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. As of December 31, 2024, total unconditional purchase obligations, excluding lease commitments, are estimated to be approximately $13.9 million.

We have certain commitments under our agreements with Akeso. The License Agreement with Akeso also contains certain manufacturing and purchase commitments. As of December 31, 2024, we are 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. For additional information about the License Agreement with Akeso, refer to Note 5, “Akeso License and Collaboration Agreement” to the Consolidated Financial Statements included under Item 15, “Exhibits, Financial Statement Schedules.”

Indemnifications

Our certificate of incorporation provides that it will indemnify the directors and officers to the fullest extent permitted by Delaware law. In addition, we have entered into indemnification agreements with all of the directors and executive officers. These indemnification agreements may require us, among other things, to indemnify each such director or executive officer for some expenses, including attorneys’ fees, judgments, fines, and settlement amounts incurred by him or her in any action or proceeding arising out of his or her service as one of our directors or executive officers. We believe the fair value for these indemnification obligations is minimal. Accordingly, we have not recognized any liabilities relating to these obligations as of December 31, 2024.

Legal Proceedings

From time to time, we may become involved in legal proceedings arising in the ordinary course of our business. We are not currently subject to any material legal proceedings.

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 consolidated financial statements, which have been prepared in accordance with United States generally accepted accounting principles. The preparation of these financial statements requires us to make estimates and judgments that affect the reported amounts of assets, liabilities, and expenses and the disclosure of contingent assets and liabilities in our financial statements. On an ongoing basis, we evaluate our estimates and judgments, including those related to accrued 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.

We believe the following critical accounting policies affect the most significant judgments, assumptions and estimates we use in preparing the consolidated financial statements:

Acquired In-Process Research and Development

The Company may enter into agreements with collaboration partners for the development and commercialization of its products. These arrangements may include payments contingent on the occurrence of certain events such as development, regulatory or sales-based milestones. The Company considers the unique nature, terms and facts and circumstances of each transaction. The Company considers whether or not the assets acquired have a future alternative use.

The fair value associated with acquired in-process research and development which does not have an alternative future use is expensed and is recorded as research and development expense. Any development or commercial milestone payments are recognized when the achievement of the associated milestone becomes probable and will either be expensed or capitalized depending upon whether or not regulatory approval has been obtained.

Research and Development Costs

Research and development costs are expensed as incurred. Research and development expenses consist of costs incurred to discover, research and develop product candidates, including personnel expenses, stock-based compensation expense, allocated facility-related and depreciation expenses, third-party license fees and external costs of outside vendors engaged to conduct preclinical and clinical development activities and clinical trials as well as to manufacture clinical trial materials. Non- refundable prepayments for goods or services that will be used or rendered for future research and development activities are recorded as prepaid expenses. Such amounts are recognized as an expense as the goods are delivered or the related services are performed, or until it is no longer expected that the goods will be delivered, or the services rendered. The significant estimates in our accrued research and development expenses include the costs incurred for services performed by our vendors in connection with research and development activities for which we have not yet been invoiced. Milestone and other payments made to third-parties with respect to in-process research and development, in accordance with the Company’s license, acquisition and other similar agreements are expensed when determined to be probable and estimable.

The Company has entered into various research and development contracts with other companies. These agreements are generally cancellable, and related payments are recorded as research and development expenses as incurred. The Company records accruals for estimated ongoing research and development costs or prepaid expenses where the payments made exceed the estimated costs. These amounts are determined based on the estimated costs to complete each study or activity, the estimation of the current stage of completion and the invoices received, as well as predetermined milestones which are not reflective of the current stage of development for prepaid expenses. Actual results could differ from the Company’s estimates. In all cases, the full cost of each study or activity is expensed by the time the final report or where applicable, product, has been received. The Company’s historical estimates have not been materially different from the actual costs.

Stock-Based Compensation

The Company measures and recognizes compensation expense for all stock option and restricted stock unit awards based on the estimated fair value of the award on the grant date. The Company uses the Black-Scholes option pricing model to estimate the fair value of stock option awards. Additionally, the Company uses a Monte Carlo simulation model to calculate the estimated fair value on the date of grant related to awards with market-based service conditions. The fair value is recognized as expense, over the requisite service period, which is generally the vesting period of the respective award, on a straight-line basis for each separately vesting portion of the award when the only condition to vesting is continued service.If vesting is subject to a market or performance condition, recognition is based on the derived service period of the award. Expense for awards with performance conditions is estimated and adjusted on a quarterly basis based upon the assessment of the probability that the performance condition will be met. Use of the Black-Scholes option-pricing model requires management to apply judgment under subjective assumptions.These assumptions include:

•Expected term—The expected term of stock options represents the weighted-average period the stock options are expected to be outstanding. The Company uses the simplified method for estimating the expected term as provided by the Securities and Exchange Commission. The simplified method calculates the expected term as the average of the time-to-vesting and the contractual life of the options.

•Expected volatility—The expected volatility is calculated based on historical volatility of the Company’s share price.

•Risk-free interest rate—The risk-free rate assumption is based on the U.S. Treasury instruments, the terms of which were consistent with the expected term of the Company’s stock options.

•Expected dividend—The expected dividend assumption is based on the Company’s history and expectation of dividend payouts. The Company has not paid and does not intend to pay dividends.

The Company uses a Monte Carlo simulation model to estimate the fair value of Performance and Market-based Stock Options at the date of grant. Key assumptions used in the model include the risk-free interest rate, which reflects the US Treasury Constant Maturity Yield with a term commensurate with the contractual term of the award, and stock price volatility, which is derived based on the historical volatility of the Company’s stock.

The Company estimates expected forfeitures at the time of grant instead of accounting for forfeitures as they occur. Stock option awards have been granted at fair value to non-employees, in connection with research and consulting services provided to the Company, to non-employees in connection with corporate activities, and to employees, in connection with Stock Purchase and Restriction Agreements. Equity awards generally vest over terms of 3 or 4 years.

The Company classifies stock-based compensation expense in the consolidated statements of operations and comprehensive loss in the same manner in which the award recipient’s payroll costs are classified.

Income Taxes

The provision for income taxes is determined using the asset and liability approach. Tax laws may require items to be included in tax filings at different times than the items are reflected in the financial statements. A current asset or liability is recognized for the estimated taxes receivable or payable for the current year. Deferred taxes represent the future tax consequences expected to occur when the reported amounts of assets and liabilities are recovered or paid. Deferred taxes are initially recognized at enacted tax rates in force at the time of initial recognition and are subsequently adjusted for any enacted changes in tax rates and tax laws. Subsequent changes to deferred taxes originally recognized in equity are recognized in income. Valuation allowances are recorded to reduce deferred tax assets when it is more likely than not that a tax benefit will not be realized. The Company has recorded a full valuation allowance against the deferred tax assets in excess of its deferred tax liabilities, as the deferred tax liability represents future reversals of existing taxable temporary differences. The Company records interest and penalties related to income tax matters as part of income tax expense.

The Company accounts for uncertainty in income taxes by applying a two-step process to determine the amount of tax benefit to be recognized. First, the tax position must be evaluated to determine the likelihood that it will be sustained upon external examination by the taxing authorities. If the tax position is deemed more-likely-than-not to be sustained, the tax position is then assessed as the amount of benefit to recognize in the consolidated financial statements. The amount of benefits that may be used is the largest amount that has a greater than 50% likelihood of being realized upon ultimate settlement. The provision for income taxes includes the effects of any resulting tax reserves, or unrecognized tax benefits, that are considered appropriate, as well as the related net interest and penalties. At December 31, 2024 and 2023, the Company had unrecognized tax positions of $2.1 million and $1.1 million, respectively. Due to the Company’s full valuation allowance, the unrecognized tax benefits would not materially impact the Company’s effective tax rate when recognized. The Company does not anticipate the total amount of unrecognized tax benefits to significantly increase or decrease in the next 12 months. The Company’s policy is to recognize interest and penalties related to uncertain tax positions as part of its income tax provision.

Recent Accounting Pronouncements

For a discussion of recent accounting pronouncements, please see Note 4 to our consolidated financial statements contained in this Annual Report on Form 10-K.

Item 7A. Quantitative and Qualitative Disclosures About Market Risk

Our primary exposures to market risk are liquidity risk and foreign currency risk.

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 $1.3 million of research and development tax credits outstanding at December 31, 2024. Given that these receivables relate to U.K. 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 8. Financial Statements and Supplementary Data

The financial statements required to be filed pursuant to this Item 8 are included in this Annual Report on Form 10-K. An index of those financial statements is found in Item 15.

Item 9. Changes in and Disagreements with Accountants on Accounting and Financial Disclosure

None.

Item 9A. Controls and Procedures

Evaluation of Disclosure Controls and Procedures

We have performed 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 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 December 31, 2024, our Co-Chief Executive Officer and Executive Chairman 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.

Management’s Report on Internal Control Over Financial Reporting

Our management is responsible for establishing and maintaining adequate internal control over financial reporting. Our internal control over financial reporting is a process designed, under the supervision of the Co-Chief Executive Officers (our Principal Executive Officers), and our Chief Operating Officer and Chief Financial Officer (our Principal Financial Officer), to provide reasonable assurance regarding the reliability of financial reporting and the preparation of our financial statements for external reporting purposes in accordance with generally accepted accounting principles.

Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, projections of any evaluation of the effectiveness of internal control to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

Our management has assessed the effectiveness of internal control over financial reporting as of December 31, 2024, based on the “Internal Control—Integrated Framework” issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO) in 2013. Based on this assessment, management concluded that, as of December 31, 2024, our internal control over financial reporting is effective based on the COSO internal control criteria.

The effectiveness of the Company’s internal control over financial reporting as of December 31, 2024 has been audited by PricewaterhouseCoopers LLP, an independent registered public accounting firm, as stated in its report included in Item 15 of this Annual Report on Form 10-K.

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 December 31, 2024 that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.

Item 9B. Other Information

Rule 10b5-1 Trading Plans.

None.

Item 9C. Disclosure Regarding Foreign Jurisdictions that Prevent Inspections

Not applicable.

PART IIIs

Item 10. Directors, Executive Officers and Corporate Governance

The information required in response to this item will be set forth in our definitive proxy statement for the 2025 annual meeting of stockholders and is incorporated herein by reference.

Item 11. Executive Compensation

The information required in response to this item will be set forth in our definitive proxy statement for the 2025 annual meeting of stockholders and is incorporated herein by reference.

Item 12. Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters

The information required in response to this item will be set forth in our definitive proxy statement for the 2025 annual meeting of stockholders and is incorporated herein by reference.

Item 13. Certain Relationships and Related Party Transactions

The information required in response to this item will be set forth in our definitive proxy statement for the 2025 annual meeting of stockholders and is incorporated herein by reference.

Item 14. Principal Accounting Fees and Services

The information required in response to this item will be set forth in our definitive proxy statement for the 2025 annual meeting of stockholders and is incorporated herein by reference.

PART IV

Item 15. Exhibits, Financial Statement Schedules

(1) Financial Statements

As part of this Annual Report on Form 10-K, the consolidated financial statements are listed in the accompanying index to financial statements on page 87.

(2) Financial Statement Schedules

All financial statement schedules have been omitted because they are not applicable, not required, or the information required is shown in the consolidated financial statements or the notes thereto.

(3) Exhibits

The exhibits filed as part of this Annual Report on Form 10-K are listed below.

Exhibit No. Description

14.1* Code of Business Conduct and Ethics of Summit Therapeutics Inc.

19.1* Insider Trading Policy

21.1* List of Significant Subsidiaries

Exhibit No. Description

101.SCH* Inline XBRL Taxonomy Extension Schema Document

101.CAL* Inline XBRL Taxonomy Extension Calculation Linkbase Document

101.DEF* Inline XBRL Taxonomy Extension Definition Linkbase Document

101.LAB* Inline XBRL Taxonomy Extension Label Linkbase Document

101.PRE* Inline XBRL Taxonomy Extension Presentation Linkbase Document

* Filed herewith.

# Indicates management contract or compensatory plan or arrangement.

Item 16. Report Summary

None.

SIGNATURES

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, as amended, the Registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

SUMMIT THERAPEUTICS INC.

By: /s/ Robert W. Duggan

By: /s/ Mahkam Zanganeh

By: /s/ Manmeet S. Soni

Date: February 24, 2025

Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, this Report has been signed below by the following persons on behalf of the Registrant in the capacities and on the dates indicated.

Name Title Date

Robert W. Duggan

Dr. Mahkam Zanganeh

Manmeet S. Soni

Bhaskar Anand

/s/ Robert F. Booth Director February 24, 2025

Dr. Robert F. Booth

/s/ Alessandra Cesano Director February 24, 2025

Dr. Alessandra Cesano

/s/ Kenneth Clark Director February 24, 2025

Kenneth Clark

/s/ Jeff Huber Director February 24, 2025

Jeff Huber

/s/ Mostafa Ronaghi Director February 24, 2025

Mostafa Ronaghi

/s/ Yu Xia Director February 24, 2025

Dr. Yu Xia

Summit Therapeutics Inc. Page

Index to the Financial Statements

Report of Independent Registered Public Accounting Firm (PCAOB ID 238) 88

Consolidated Balance Sheets 90

Consolidated Statements of Operations and Comprehensive Loss 91

Consolidated Statements of Stockholders' Equity 92

Consolidated Statements of Cash Flows 93

Notes to the Consolidated Financial Statements 94

Report of Independent Registered Public Accounting Firm

To theBoard of Directors and Stockholders of Summit Therapeutics Inc.

Opinions on the Financial Statements and Internal Control over Financial Reporting

We have audited the accompanying consolidated balance sheets of Summit Therapeutics Inc. and its subsidiaries (the “Company”) as of December 31, 2024 and 2023, and the related consolidated statements of operations and comprehensive loss, of stockholders’ equity and of cash flows for each of the three years in the period ended December 31, 2024, including the related notes (collectively referred to as the “consolidated financial statements”). We also have audited the Company's internal control over financial reporting as of December 31, 2024, based on criteria established in Internal Control - Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO).

In our opinion, the consolidated financial statements referred to above present fairly, in all material respects, the financial position of the Company as of December 31, 2024 and 2023, and the results of its operations and its cash flows for each of the three years in the period ended December 31, 2024 in conformity with accounting principles generally accepted in the United States of America. Also in our opinion, the Company maintained, in all material respects, effective internal control over financial reporting as of December 31, 2024, based on criteria established in Internal Control - Integrated Framework(2013)issued by the COSO.

Basis for Opinions

The Company's management is responsible for these consolidated financial statements, for maintaining effective internal control over financial reporting, and for its assessment of the effectiveness of internal control over financial reporting, included in Management's Report on Internal Control Over Financial Reporting appearing under Item 9A. Our responsibility is to express opinions on the Company’s consolidated financial statements and on the Company's internal control over financial reporting based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (PCAOB) and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audits to obtain reasonable assurance about whether the consolidated financial statements are free of material misstatement, whether due to error or fraud, and whether effective internal control over financial reporting was maintained in all material respects.

Our audits of the consolidated financial statements included performing procedures to assess the risks of material misstatement of the consolidated financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the consolidatedfinancial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the consolidated financial statements. Our audit of internal control over financial reporting included obtaining an understanding of internal control over financial reporting, assessing the risk that a material weakness exists, and testing and evaluating the design and operating effectiveness of internal control based on the assessed risk. Our audits also included performing such other procedures as we considered necessary in the circumstances. We believe that our audits provide a reasonable basis for our opinions.

Emphasis of Matter

As discussed in Note 3 to the consolidated financial statements, the Company has incurred net losses from operations and cash outflows from operating activities. Management’s evaluation of the events and conditions and management’s plans to mitigate these matters are also described in Note 3.

Definition and Limitations of Internal Control over Financial Reporting

A company’s internal control over financial reporting is a process designed 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. A company’s internal control over financial reporting includes those policies and procedures that (i) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions of the assets of the company; (ii) provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that receipts and expenditures of the company are being made only in accordance with authorizations of management and directors of the

company; and (iii) provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use, or disposition of the company’s assets that could have a material effect on the financial statements.

Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

Critical Audit Matters

The critical audit matter communicated below is a matter arising from the current period audit of the consolidated financial statements that was communicated or required to be communicated to the audit committee and that (i) relates to accounts or disclosures that are material to the consolidated financial statements and (ii) involved our especially challenging, subjective, or complex judgments. The communication of critical audit matters does not alter in any way our opinion on the consolidated financial statements, taken as a whole, and we are not, by communicating the critical audit matter below, providing a separate opinion on the critical audit matter or on the accounts or disclosures to which it relates.

Research and Development Prepaid Expenses and Accrued Liabilities

As described in Notes 4 and 14 to the consolidated financial statements, included within prepaid expenses and other assets as of December 31, 2024 is $8.3 million of prepayments relating to research and development expenditures. Included within accrued liabilities as of December 31, 2024 is $17.4 million relating to research and development expenditures. The Company records accruals for estimated ongoing research and development costs or prepaid expenses where the payments made exceed the estimated costs. These amounts are determined by management based on the estimated costs to complete each study or activity, the estimation of the current stage of completion and the invoices received, as well as predetermined milestones which are not reflective of the current stage of development for prepaid expenses. However, prepaid expenses decrease, and accrued liabilities increase as the activities progress, and if actual costs incurred exceed the prepaid expense, an accrual will be recorded for the liability. 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 management’s operational knowledge of the work completed under those contracts.

The principal considerations for our determination that performing procedures relating to accrued and prepaid research and development costs is a critical audit matter are (i) the significant judgment by management when developing the estimated research and development costs and, (ii) a high degree of auditor judgment, subjectivity, and effort in performing procedures and evaluating audit evidence related to management’s significant assumptions related to the estimated current stage of completion of each study or activity.

Addressing the matter involved performing procedures and evaluating audit evidence in connection with forming our overall opinion on the consolidated financial statements. These procedures included testing the effectiveness of controls related to the accrued and prepaid research and development costs process, including controls over the development of estimated research and development costs. These procedures also included, among others, (i) evaluating management’s process on a sample basis for determining the current stage of completion of each study or activity; (ii) reading a sample of research and development contracts; (iii) evaluating the reasonableness of progress towards completion for a sample of research and development activities and the associated incurred cost based on invoices, external confirmations or other information received from the supplier; and (iv) testing the completeness and accuracy of the underlying data including total costs included within contracts and actual billed amounts for a sample of contracts.

/s/ PricewaterhouseCoopers LLP

San Jose, California

February 24, 2025

We have served as the Company’s auditor since 2021.

Summit Therapeutics Inc.

Consolidated Balance Sheets

(in thousands, except share and per share data)

Assets

Current assets:

Restricted cash 325 —

Prepaid expenses and other current assets 10,519 2,622

Research and development tax credit receivable 557 848

Non-current assets:

Property and equipment, net 254 204

Operating lease right-of-use assets 7,144 5,859

Research and development tax credit receivable 698 959

Liabilities and stockholders’ equity

Current liabilities:

Operating lease liabilities, current portion 3,765 2,809

Non-current liabilities:

Operating lease liabilities, net of current portion 3,453 3,290

Other non-current liabilities 1,630 1,562

Promissory note payable to a related party — 100,000

Commitments and contingencies (Note 19)

Stockholders’ equity:

Accumulated other comprehensive loss (2,285) (2,448)

Total liabilities and stockholders' equity $ 435,560 $ 202,949

The accompanying notes are an integral part of the consolidated financial statements

Summit Therapeutics Inc.

Consolidated Statements of Operations and Comprehensive Loss

(in thousands, except share and per share data)

Year Ended December 31,

Revenue $ — $ — $ 705

Operating expenses:

Acquired in-process research and development 15,007 520,915 —

Impairment of intangible assets — — 8,468

Net loss per share:

Weighted average common shares outstanding:

Other comprehensive income (loss):

Foreign currency translation adjustments 60 (172) 304

Unrealized gain on short-term investments 100 36 —

The accompanying notes are an integral part of the consolidated financial statements.

Summit Therapeutics Inc.

Consolidated Statements of Stockholders’ Equity

(in thousands, except share data)

Shares Amount

Foreign currency translation adjustment — — — 304 — 304

Unrealized gain on short-term investments — — — 36 — 36

Reclassification of cumulative translation gain (Note 8) — — — (419) — (419)

Foreign currency translation adjustment — — — (172) — (172)

Unrealized gain on short-term investments — — — 100 — 100

Foreign currency translation adjustment — — — 60 — 60

The accompanying notes are an integral part of the consolidated financial statements.

Summit Therapeutics Inc.

Consolidated Statements of Cash Flows

(in thousands)

Year Ended December 31,

Cash flows used in operating activities:

Adjustments to reconcile net loss to net cash used in operating activities:

Gain on remeasurement of liabilities — — (1,265)

Amortization of discount on short-term investments (2,576) (1,924) —

Unrealized foreign currency loss (gain) 229 (812) 2,616

Reclassification of currency translation gain — (419) —

Impairment of fixed assets — 474 —

Amortization of intangible assets — — 914

Impairment of intangible assets — — 8,468

Loss on disposal of assets — (109) —

Acquired in-process research and development expense 15,007 520,915 —

Changes in operating assets and liabilities:

Prepaid expenses and other current assets (7,905) (914) 5,107

Research and development tax credit receivable 535 4,168 8,437

Deferred revenue and other income — — (7,278)

Accrued liabilities and other current liabilities 11,879 (2,377) 4,782

Other long-term liabilities 95 — —

Operating lease right-of-use assets and lease liabilities, net (167) (359) 152

Cash flows used in investing activities:

Purchase of property and equipment (139) (128) (624)

Proceeds from sale of property, plant and equipment — 226 —

Maturities and sales of short-term investments 489,837 208,165 —

Cash flows provided by financing activities:

Proceeds from the issuance of common stock for rights offering — 104,686 100,000

Net receipts related to the exercise of warrants 598 1,203 —

Proceeds from related party promissory notes — — 545,000

Payments of related party promissory notes issuance costs — — (44)

Effect of exchange rates on cash and cash equivalents (18) 839 (1,222)

Supplemental Disclosure of Cash Flow Information:

Cash paid for interest on related party promissory note $ 8,806 $ 10,650 $ 434

Cash paid for income taxes $ — $ 52 $ —

Supplemental Disclosure of Non-Cash Investing and Financing Activities:

Debt issuance costs in accrued expenses $ — $ — $ 31

Deferred transaction costs included in other non-current assets $ — $ — $ 425

The accompanying notes are an integral part of the consolidated financial statements.

Notes to Consolidated Financial Statements

1. Nature of Business and Operations

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

The Company’s current lead development candidate is ivonescimab, a novel, potential first-in-class bispecific antibody intending to combine the effects of immunotherapy via a blockade of PD-1 with the anti-angiogenesis effects of an anti-VEGF compound into a single molecule. On December 5, 2022, the Company entered into a Collaboration and License Agreement (the “License Agreement”) with Akeso, Inc. and its affiliates (collectively, “Akeso”) pursuant to which the Company has in-licensed intellectual property related to ivonescimab, as further described in Note 5. 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 with Akeso to expand its territories covered under the License Agreement to also include the Latin America, Middle East and Africa regions (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.

2. Basis of Presentation and Use of Estimates

Basis of Presentation

The consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”) and pursuant to the rules and regulations of the U.S. Securities and Exchange Commission. Any reference in these notes to applicable guidance is meant to refer to authoritative U.S. GAAP as found in the Accounting Standards Codification (“ASC”) and as amended by Accounting Standards Updates (“ASU”) of the Financial Accounting Standards Board (“FASB”). Certain reclassifications have been made to the prior years’ financial statements to conform to current year presentation.

Use of Estimates

The preparation of these financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the reported amounts of revenues 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, other long-lived assets 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.

3. Liquidity and Capital Resources

During the year ended December 31, 2024, the Company incurred a net loss of $221,315 and cash flows used in operating activities was $142,106. As of December 31, 2024, the Company had an accumulated deficit of $1,214,573, and cash and cash equivalents of $104,862 and short term investments in U.S. treasury securities of $307,487. The Company expects to continue to generate operating losses for the foreseeable future.

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 consolidated financial statements.

Summit Therapeutics Inc.

Notes to Consolidated Financial Statements

(in thousands, except share and per share data)

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.

4. Summary of Significant Accounting Policies and Recent Accounting Pronouncements

The significant accounting policies adopted by the Company in the preparation of these consolidated financial statements are set out below. These policies have been consistently applied to all the years presented, unless otherwise stated.

Principles of Consolidation

The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the U.S. GAAP and pursuant to the rules and regulations of the U.S. Securities and Exchange Commission. The consolidated financial statements reflect the accounts of Summit Therapeutics Inc. and its wholly owned subsidiaries. Intercompany balances and transactions are eliminated in consolidation.

Foreign Currency Translation

The financial statements of the Company’s subsidiaries with functional currencies other than the U.S. dollar are translated into U.S. dollars using period-end exchange rates for assets and liabilities, historical exchange rates for stockholders’ equity and weighted average exchange rates for operating results. Translation gains and losses are included in accumulated other comprehensive (loss) income in stockholders’ equity. Foreign currency transaction gains and losses are included in other expense, net in the results of operations. The Company recorded realized and unrealized foreign currency transaction (loss) gain of ($97), $613 and ($4,109) for the years ended December 31, 2024, 2023 and 2022, respectively, which is included in other expense, net in the statements of operations and comprehensive loss.

Other Operating (Expense) Income, Net

The Company generated income from government contracts that reimburse the Company for certain allowable costs for funded projects. For contracts with government agencies where the funding arrangement is considered central to the Company’s ongoing operations, the Company classifies the recognized funding received within other operating (expense) income, net in the consolidated statements of operations and comprehensive loss.

Income from government grants is recognized as the qualifying expenses related to the contracts are incurred, provided that there is reasonable assurance of recoverability. If the government agency approves the project proposed by the Company, the government agency funds the project upon receipt of the support for the costs incurred up to the contract limit. Income recognized upon incurring qualifying expenses in advance of billing is recorded as unbilled receivable, a component of other current assets, in the consolidated balance sheet.

Grant income is not recognized as deductions of research and development costs because the Company acts as the principal in conducting the research and development activities and these contracts are central to its ongoing operations. The funds received through these means are held as deferred income in the consolidated balance sheets and are released to the consolidated statement of operations and comprehensive loss, classified as other operating (expense) income, net, as the underlying expenditure is incurred and to the extent the conditions of the grant are met. The related costs incurred by the Company are included in research and development expense in the Company’s consolidated statements of operations and comprehensive loss.

Summit Therapeutics Inc.

Notes to Consolidated Financial Statements

(in thousands, except share and per share data)

The Company benefits from two United Kingdom ("U.K.") research and development (“R&D”) tax credit cash rebate regimes: Small and Medium Enterprise (“SME”) Program and the Research and Development Expenditure Credit (“RDEC”) Program. Each reporting period, management evaluates which tax relief programs the Company is expected to be eligible for and records as other operating (expense) income, net the portion of the expense that it expects to qualify under the programs, that it plans to submit a claim for, and it has reasonable assurance that the amount will ultimately be realized.

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. The dilutive effect of share options and warrants are determined under the treasury stock method using the average market price for the period.In addition, the assumed proceeds under the treasury stock method include the average unrecognized compensation expense of stock options and warrants that are in-the-money.

Goodwill

Goodwill represents the excess of the consideration transferred over the fair value of net assets acquired. Goodwill is assigned to reporting units at the time of acquisition or when there is a change in the reporting structure and bases that allocation on which reporting units will benefit from the acquired assets and liabilities. Reporting units are defined as operating segments or one level below an operating segment, referred to as a component. Typically acquisitions related to a single reporting unit do not require the allocation of goodwill to multiple reporting units. If the net assets obtained in an acquisition are assigned to multiple reporting units, the goodwill is distributed to the respective reporting units as part of the purchase price allocation process.

The Company assesses goodwill for impairment on an annual basis as of December 31 or more frequently when events and circumstances occur indicating that the recorded goodwill may be impaired. The Company regularly monitors current business conditions and other factors including, but not limited to, adverse industry or economic trends and lower projections of profitability that may impact future operating results. The process of evaluating the potential impairment of goodwill requires significant judgment. In performing the Company’s annual goodwill impairment test, the Company is permitted to first assess qualitative factors to determine whether it is more likely than not that the fair value of the Company’s reporting unit is less than its carrying amount, including goodwill. In performing the qualitative assessment, the Company considers certain events and circumstances specific to the reporting unit and to the entity as a whole, such as macroeconomic conditions, industry and market considerations, overall financial performance and cost factors when evaluating whether it is more likely than not that the fair value of the reporting unit is less than its carrying amount. The Company is also permitted to bypass the qualitative assessment and proceed directly to the quantitative test. If the Company chooses to undertake the qualitative assessment and concludes that it is more likely than not that the fair value of the reporting unit is less than its carrying amount, the Company would then proceed to the quantitative impairment test. In the quantitative assessment, the Company compares the fair value of the reporting unit to its carrying amount, which includes goodwill. If the fair value exceeds the carrying value, no impairment loss exists. If the fair value is less than the carrying amount, a goodwill impairment loss is measured and recorded.

Intangible Assets and Long-lived Assets

The Company evaluates the recoverability of its intangible and long-lived assets whenever events and changes in circumstances indicate that the carrying amount of an asset or asset group may not be fully recoverable. If events and circumstances indicate that the carrying amount may not fully be recoverable, the carrying values of the asset or asset group are evaluated in relation to their operating performance and future undiscounted cash flows of the underlying business. If the future undiscounted cash flows are less than their carrying value, impairment exists. The impairment is measured as the difference between the carrying value and the fair value of the underlying asset or asset group. Fair values are based on estimates of market prices and assumptions concerning the amount and timing of estimated future cash flows and assumed discount rates, reflecting varying degrees of perceived risk.

Summit Therapeutics Inc.

Notes to Consolidated Financial Statements

(in thousands, except share and per share data)

Property and Equipment

Property and equipment are stated at cost less accumulated depreciation. Cost is comprised of the purchase price plus any incidental costs of acquisition and commissioning.

Depreciation is calculated based on cost, less residual value, in equal annual installments over the estimated useful lives of the assets. The residual value, if significant, is reassessed annually.

Laboratory equipment 2 - 10 years

Furniture and fixtures, office equipment and software 3 - 5 years

Depreciation is recognized as part of the general and administrative and research and development expense lines shown on the face of the consolidated statement of operations and comprehensive loss depending on the nature of the underlying assets.

Expenditures for repairs and maintenance are expensed as incurred. Upon retirement or sale, the cost of assets disposed of and the related accumulated depreciation are removed from the accounts and any resulting gain or loss is included in loss from operations.

Leases

The Company has operating leases for real estate. The Company does not have any finance leases. A contract is or contains a lease when the lessee has the right to control the use of an identified asset. The Company determines if an arrangement is a lease at inception of the contract, which is the date on which the terms of the contract are agreed to and the agreement creates enforceable rights and obligations. The lease term used to calculate the lease liability include options to extend or terminate the lease when it is reasonably certain that the option will be exercised.

At the lease commencement date, the Company measures and recognizes a lease liability and a right-of-use asset in the financial statements. Lease liabilities are recognized based on the present value of the future lease payments over the lease term at commencement date. The right-of use asset is measured by taking the present value of future lease payments, plus any incremental direct costs incurred, less any lease incentives received. As most of the Company’s leases do not provide an implicit rate, the Company uses an estimated incremental borrowing rate based on the lease term and the economic environment of the lease at the lease commencement date, which is then utilized to determine the present value of future lease payments. Lease expense for minimum lease payments are recognized on a straight-line basis over the lease term, with variable lease payments recognized in the periods in which they are incurred.

The Company has existing lease agreements with lease and non-lease components, has elected to account for the lease and non-lease components as a single lease component, and has allocated all of the contract consideration to the lease component only.

Leases with an initial lease term of 12 months or less are not recorded on the balance sheet. The Company recognizes lease expense for its short-term leases on a straight-line basis over the lease term.

Acquired In-Process Research and Development

Summit Therapeutics Inc.

Notes to Consolidated Financial Statements

(in thousands, except share and per share data)

Research and Development Costs

Research and development costs are expensed as incurred. Research and development expenses consist of costs incurred to discover, research and develop product candidates, including personnel expenses, stock-based compensation expense, allocated facility-related and depreciation expenses, third-party license fees and external costs of outside vendors engaged to conduct preclinical and clinical development activities and clinical trials as well as to manufacture clinical trial materials. Non-refundable prepayments for goods or services that will be used or rendered for future research and development activities are recorded as prepaid expenses. Such amounts are recognized as an expense as the goods are delivered or the related services are performed, or until it is no longer expected that the goods will be delivered, or the services rendered. Milestone and other payments made to third-parties with respect to in-process research and development, in accordance with the Company’s license, acquisition and other similar agreements are expensed when determined to be probable and estimable.

Stock-Based Compensation

The Company measures and recognizes compensation expense for all stock option awards based on the estimated fair value of the award on the grant date. The Company uses the Black-Scholes option pricing model to estimate the fair value of stock option awards. Additionally, the Company uses a Monte Carlo simulation model to calculate the estimated fair value on the date of grant related to awards with market-based service conditions. The fair value is recognized as expense, over the requisite service period, which is generally the vesting period of the respective award, on a straight-line basis for each separately vesting portion of the award when the only condition to vesting is continued service.If vesting is subject to a market or performance condition, recognition is based on the derived service period of the award. Expense for awards with performance conditions is estimated and adjusted on a quarterly basis based upon the assessment of the probability that the performance condition will be met. Use of the Black-Scholes option-pricing model requires management to apply judgment under subjective assumptions.These assumptions include:

•Expected term—The expected term of stock options represents the weighted-average period the stock options are expected to be outstanding. The Company uses the simplified method for estimating the expected term as provided by the SEC. The simplified method calculates the expected term as the average of the time-to-vesting and the contractual life of the options.

•Expected volatility—The expected volatility is calculated based on historical volatility of the Company’s share price.

•Risk-free interest rate—The risk-free rate assumption is based on the U.S. Treasury instruments, the terms of which were consistent with the expected term of the Company’s stock options.

•Expected dividend—The expected dividend assumption is based on the Company’s history and expectation of dividend payouts. The Company has not paid and does not intend to pay dividends.

The Company uses a Monte Carlo simulation model to estimate the fair value of Performance and Market-based Stock Options at the date of grant which utilizes multiple input variables to estimate the probability that the market condition will be achieved. Key assumptions used in the model include the risk-free interest rate, which reflects the US Treasury Constant Maturity Yield with a term commensurate with the contractual term of the award, and stock price volatility, which is derived based on the historical volatility of the Company’s stock.

Summit Therapeutics Inc.

Notes to Consolidated Financial Statements

(in thousands, except share and per share data)

Income Taxes

Concentration of Credit Risk

Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash and cash equivalents, restricted cash and short-term investments. The Company’s cash is comprised of short-term cash deposits at a variety of financial institutions which the Company believes are of high credit ratings in amounts that may exceed federally insured limits. The Company has not experienced any losses on such accounts. Cash balances maintained during the year have been principally held with U.S.-based and U.K.-based banks. The Company does not believe it is exposed to any unusual credit risk beyond the normal credit risk associated with commercial banking relationships.

The Company relies, and expects to continue to rely, on a number of vendors to conduct its clinical trials and preclinical studies, manufacture drug product and supply clinical trial and preclinical study materials for its development programs. These programs could be adversely affected by a significant interruption in these services or the availability of materials.

Fair Value Measurements

In accordance with the provisions of fair value accounting, a fair value measurement assumes that the transaction to sell an asset or transfer a liability occurs in the principal market for the asset or liability or, in the absence of a principal market, the most advantageous market for the asset or liability and defines fair value based on the exit price model.

The fair value measurement guidance establishes a fair value hierarchy, which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The guidance describes three levels of inputs that may be used to measure fair value:

Level 1

Quoted prices in active markets for identical assets or liabilities as of the reporting date. Active markets are those in which transactions for the asset or liability occur in sufficient frequency and volume to provide pricing information on an ongoing basis.

Level 2

Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 2 assets and liabilities include debt securities with quoted prices that are traded less frequently than exchange-traded instruments or securities or derivative contracts that are valued using a pricing model with inputs that are observable in the market or can be derived principally from or corroborated by observable market data.

Level 3

Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. Level 3 assets and liabilities include financial instruments whose value is determined using pricing models,

Summit Therapeutics Inc.

Notes to Consolidated Financial Statements

(in thousands, except share and per share data)

discounted cash flow methodologies, or similar techniques, as well as instruments for which the determination of fair value requires significant management judgment or estimation.

In certain cases, the inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, the Company categorizes such assets and liabilities based on the lowest level input that is significant to the fair value measurement in its entirety. The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and considers factors specific to the asset.

Cash and Cash Equivalents

The Company considers only those investments that are highly liquid, readily convertible to cash and that mature within 90 days or less from date of purchase to be cash equivalents. As of December 31, 2024, cash equivalents were comprised of money market funds. As of December 31, 2023, cash equivalents were comprised of money market funds and U.S. treasury securities.

Restricted Cash

Restricted cash represents amounts which are legally restricted to withdrawal or usage and is presented in the consolidated balance sheet as restricted cash. On December 15, 2022, the Company transferred $300,000 into an escrow fund reserved for the Company’s initial upfront payment to Akeso in connection with the License Agreement, as described further in Note 5. Following the Antitrust Clearance Date, on January 17, 2023, the License Agreement closed and Akeso was issued 10,000,000 shares of Company common stock pursuant to the Common Stock Issuance Agreement and was paid $274,900 in cash as the initial upfront payment. The remaining amounts in escrow were returned to the Company’s operating cash accounts. As of December 31, 2024 the Company has $325 of restricted cash associated with an irrevocable letter of credit required by the landlord to enter into the lease for Company's corporate office.

The Company’s total cash, cash equivalents and restricted cash balances were as follows:

Year Ended December 31,

Short-term Investments

Marketable securities consist of investments with original maturities greater than ninety days from the date of acquisition. The Company classifies investments with maturities of greater than 90 days and less than one year as short-term, based on the liquid nature of the securities and because such marketable securities represent the investment of cash that is available for current operations. The Company considers its investment portfolio of investments as available-for-sale. Accordingly, these investments are recorded at fair value, which is based on quoted market prices or other observable inputs. Unrealized gains and losses are recorded as a component of other comprehensive income (loss). Realized gains and losses are determined on a specific identification basis and are included in other (expense) income. Amortization and accretion of discounts and premiums are also recorded in other (expense) income.

When the fair value is below the amortized cost of the asset, an estimate of expected credit losses is made. This estimate is limited to the amount by which fair value is less than amortized cost. The credit-related impairment amount is recognized in the consolidated statements of operations and comprehensive loss and the remaining impairment amount and unrealized gains are reported as a component of accumulated other comprehensive income (loss) in stockholders’ equity. Credit losses are recognized through the use of an allowance for credit losses account and subsequent improvements in expected credit losses are recognized as a reversal of the allowance account. If the Company has the intent to sell the security or it is more likely than not that the Company will be required to sell the security prior to recovery of its amortized cost basis the allowance for credit loss is written off and the excess of the amortized cost basis of the asset over its fair value is recorded in the consolidated statements of operations and comprehensive loss.

100

Summit Therapeutics Inc.

Notes to Consolidated Financial Statements

(in thousands, except share and per share data)

Warrants

Warrants issued by the Company are recognized and classified as equity when, upon exercise, the Company would issue a fixed amount of its own equity instruments (common stock) in exchange for a fixed amount of cash or another financial asset.

Consideration received, net of incremental costs directly attributable to the issue of such new warrants, is shown in stockholders' equity. Such warrants are not remeasured at fair value in subsequent reporting periods.

Warrants issued in which external services are received as consideration for equity instruments of the company should be measured at the fair value of the goods or services received. Only if the fair value of the services cannot be measured reliably would the fair value of the equity instruments granted be used. The fair value for the warrants is calculated using the Black-Scholes model and recorded in the consolidated statement of operations and comprehensive losson a straight-line basis over the period of the consulting services. If the services are terminated prior to the end of the consultancy agreement, the warrants cease vesting and any unvested portion of the warrants will lapse immediately.

The warrants in issue are classified within stockholders’ equity as they are indexed to the Company’s own shares of common stock and require settlement in its shares of common stocks with no provision for any cash settlement.

Recently Issued or Adopted Accounting Pronouncements

In December 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards update “ASU” No. 2023-09, “Improvements to Income Tax Disclosures”, which requires disclosure of disaggregated income taxes paid, prescribes standard categories for the components of the effective tax rate reconciliation, and modifies other income tax-related disclosures. ASU No. 2023-09 is effective for fiscal years beginning after December 15, 2024 and allows for adoption on a prospective basis, with a retrospective option. Early adoption is permitted. The Company is currently evaluating the impact of the ASU on the income tax disclosures within the consolidated financial statements.

In November 2023, the FASB issued ASU No. 2023-07, “Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures”, which provides updates to qualitative and quantitative reportable segment disclosure requirements, including enhanced disclosures about significant segment expenses and increased interim disclosure requirements, among others. ASU No. 2023-07 is effective for fiscal years beginning after December 15, 2023, and interim periods in fiscal years beginning after December 15, 2024. Early adoption was permitted, and the amendments should be applied retrospectively. The Company adopted and retrospectively applied the amendments in this update during the fourth quarter of 2024 and in preparation of the annual consolidated financial statements. Refer to Note 6 regarding the additional disclosures included within the consolidated financial statements.

In November 2024, the FASB issued ASU 2024-03, “Disaggregation of Income Statement Expenses.” The new standard 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 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 guidance is to be applied prospectively, with the option for retrospective application. The Company is currently evaluating the impact of the ASU on the disclosures within the consolidated financial statements.

Other recent authoritative guidance issued by the FASB (including technical corrections to the FASB ASC), the American Institute of Certified Public Accountants, and the Securities and Exchange Commission did not or are not expected to have a material impact on the Company’s consolidated financial statements.

5. Akeso License and Collaboration Agreement

On December 5, 2022, the Company entered into a Collaboration and License Agreement (the “License Agreement”) with Akeso, Inc. and its affiliates ("Akeso") pursuant to which the Company is in-licensing its breakthrough bispecific antibody, ivonescimab. The License Agreement and transaction closed in January 2023 following customary waiting periods.

101

Summit Therapeutics Inc.

Notes to Consolidated Financial Statements

(in thousands, except share and per share data)

Ivonescimab, known as AK112 in China and Australia, and also as SMT112 in the United States, Canada, Europe, and Japan, 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 engineered 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. 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 has also entered into a Supply Agreement with Akeso, pursuant to which Summit agrees to purchase a certain portion of drug substance for clinical and commercial supply. 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 our common stock in lieu of $25,100 cash. The remaining $200,000 amount of the upfront payment was paid on March 6, 2023.

Effective June 3, 2024, the Company and Akeso entered into an amendment (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 consolidated statement of operations and comprehensive loss. Acquired in-process research and development expense for the year ended December 31, 2024 was $15,007 which related to the upfront payment and immaterial transaction costs for the Second Amendment. For the year ended December 31, 2023, acquired in-process research and development expense was $520,915 which was comprised of the $474,900 paid in cash, the fair value of the 10,000,000 shares of common stock on the date of closing the transaction of $45,900, and $115 of direct transactions costs incurred for the License Agreement.

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.

102

Summit Therapeutics Inc.

Notes to Consolidated Financial Statements

(in thousands, except share and per share data)

6. 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 consolidated statement of operations and comprehensive loss to make decisions about allocating resources and assessing performance for the entire Company. The CODM function approves of 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:

Year Ended December 31,

Revenue (1) $ — $ — $ 705

Acquired in-process research and development 15,007 520,915 —

(1) Revenue relates to amounts received from the license and commercialization agreement related to ridinilazole clinical trials. All prior development activities related to ridinilazole have been terminated.

(2) Other expenses include costs for the Company’s antibiotic pipeline research activities and ridinilazole or CDI program activities (collectively, “Anti-infectives), general and administrative expenses excluding compensation and stock-based compensation, and impairment of intangible assets. All prior development activities related to Anti-infectives have been terminated.

As of December 31, 2024 and 2023, substantially all of our long-lived assets are located in the United States.

7. Other Operating Income, net

The following table sets forth the components of other operating income by category:

Year Ended December 31,

Funding income from BARDA (as defined below) $ — $ — 8,085

Grant income from CARB-X (as defined below) — 45 1,808

Other income — 10 —

103

Summit Therapeutics Inc.

Notes to Consolidated Financial Statements

(in thousands, except share and per share data)

BARDA (as defined below)

In September 2017, we were awarded a funding contract from the Biomedical Advanced Research and Development Authority (“BARDA”), part of the Office of the Assistant Secretary for Preparedness and Response at the United States Department of Health and Human Services, to fund, in part, the clinical and regulatory development of ridinilazole for the treatment of infections caused by C. difficile ("CDI"). The contract provides for a cost-sharing arrangement under which BARDA committed to funding $62,400 of estimated costs for the continued clinical and regulatory development of ridinilazole for CDI. As a result of the Company’s decision, on September 28, 2022, to not pursue further internal clinical development of ridinilazole and seek partners or a divestiture related to ridinilazole as a path forward for the clinical development of the asset, the Company recorded expenses for the remaining clinical trial costs associated with the close out activities of ridinilazole and recognized the remainder of the deferred income that had been received from BARDA. As of December 31, 2022, the Company recognized $59,203 of cumulative income under the BARDA contract and no additional income will be recognized.

Research and development credits

Research and development tax credits consists of tax credits received in the United Kingdom (“U.K.”). As of December 31, 2024 and 2023, the current and long-term research and development tax credit receivable was $1,255 and $1,807, respectively. Refer to Note 4 for information about the two U.K. research and development tax credit cash rebate regimes which the Company benefits from, as well as criteria established by the HMRC.

CARB-X (as defined below)

In May 2021, the Company received an award from the Combating Antibiotic Resistant Bacteria Biopharmaceutical Accelerator program ("CARB-X") to progress SMT-738 through preclinical development and an option to continue into Phase Ia clinical studies. The award committed initial non-dilutive funding of up to $4,100, with the possibility of up to another $3,700 based on the achievement of future milestones. As of December 31, 2022, the Company recognized $2,920 of cumulative income under the CARB-X contract and no additional income will be recognized.

8. Other Income (Expense), net

The following table sets forth the components of other (expense) income:

Year Ended December 31,

Foreign currency (losses) gains $ (97) $ 613 $ (4,109)

Reclassification of cumulative currency translation gain (2) — 419 —

(1) Investment income relates to the Company’s money market funds and short-term investments in U.S. treasury securities. Refer to Note 12 for details.

(2) The reclassification of cumulative currency translation gain related to the reclassification of cumulative foreign currency translation gains from accumulated other comprehensive loss due to the dissolution of certain dormant entities.

9. Income Tax

The Company is primarily subject to corporation taxes in the U.S. and the U.K. The calculation of the Company’s tax provision involves the application of both U.S. and U.K. tax law and requires judgment and estimates. The Company has assessed the applicability of the OECD/G20 Inclusive Framework on Base Erosion and Profit Shifting (BEPS) Pillar 2 rules, which establish a global minimum tax rate. Based on our current financial position and revenue thresholds, the Company is not large enough for

104

Summit Therapeutics Inc.

Notes to Consolidated Financial Statements

(in thousands, except share and per share data)

Pillar 2 to apply. Therefore, the provisions and requirements under Pillar 2 do not impact our financial statements for the reporting period.

Due to the Company’s full valuation allowance, the unrecognized tax benefits would not materially impact the Company’s effective tax rate when recognized. The Company does not anticipate the total amounts of unrecognized tax benefits will significantly increase or decrease in the next 12 months. The Company’s policy is to recognize interest and penalties related to uncertain tax positions as part of its income tax provision. For the years ended December 31, 2024 and 2023, the Company had no interest or penalties related to unrecognized tax benefits.

The components of the Company’s loss before income taxes are as follows:

Year Ended December 31,

The Company has not recognized a current or deferred provision for federal, state or non-United States income taxes in the years ended December 31, 2024, 2023 and 2022.

Deferred taxes are recognized for temporary differences between the basis of assets and liabilities for financial statement and income tax purposes.

105

Summit Therapeutics Inc.

SMMT US Equity

SMMT · 10-K · period ended 2024-12-31

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

Item 7A. Quantitative and Qualitative Disclosures About Market Risk

Item 8. Financial Statements and Supplementary Data

Item 9. Changes in and Disagreements with Accountants on Accounting and Financial Disclosure

Item 9A. Controls and Procedures

Item 9B. Other Information

Item 9C. Disclosure Regarding Foreign Jurisdictions that Prevent Inspections

Item 10. Directors, Executive Officers and Corporate Governance

Item 11. Executive Compensation

Item 12. Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters

Item 13. Certain Relationships and Related Party Transactions

Item 14. Principal Accounting Fees and Services

Item 15. Exhibits, Financial Statement Schedules

Item 16. Report Summary

SMMT US Equity☆

SMMT · 10-K · period ended 2024-12-31

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

Item 7A. Quantitative and Qualitative Disclosures About Market Risk

Item 8. Financial Statements and Supplementary Data

Item 9. Changes in and Disagreements with Accountants on Accounting and Financial Disclosure

Item 9A. Controls and Procedures

Item 9B. Other Information

Item 9C. Disclosure Regarding Foreign Jurisdictions that Prevent Inspections

Item 10. Directors, Executive Officers and Corporate Governance

Item 11. Executive Compensation

Item 12. Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters

Item 13. Certain Relationships and Related Party Transactions

Item 14. Principal Accounting Fees and Services

Item 15. Exhibits, Financial Statement Schedules

Item 16. Report Summary

SMMT US Equity