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

You should read the following discussion and analysis of our financial condition and results of operations together with our consolidated financial statements and the related notes thereto appearing elsewhere in this Annual Report. Some of the information contained in this discussion and analysis or set forth elsewhere in this Annual Report, including information with respect to our plans and strategy for our business, includes forward-looking statements that involve risks and uncertainties. You should review the section titled “Risk Factors” for a discussion of important factors that could cause actual results to differ materially from the results described in or implied by the forward-looking statements contained in the following discussion and analysis, as well as the section titled “Special Note Regarding Forward-Looking Statements.” The accompanying MD&A, including all periods presented, have been prepared under U.S. GAAP.

This section of our Annual Report on Form 10-K discusses our financial condition and results of operations for the fiscal years ended December 31, 2025 and 2024, and year-to-year comparisons between fiscal 2025 and fiscal 2024. A discussion of our financial condition and results of operations for the fiscal year ended December 31, 2023 and year-to-year comparisons between fiscal 2024 and fiscal 2023 that are not included in this Annual Report on Form 10-K can be found in “Management’s Discussion and Analysis of Financial Condition and Results of Operations” in Part II, Item 7 of our Annual Report on Form 10-K for the fiscal year ended December 31, 2024, filed with the SEC on February 26, 2025.

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Overview

We are a commercial stage biotechnology company pioneering and delivering transformative immunomodulating medicines to radically improve outcomes for patients with cancer, infectious diseases, and autoimmune diseases. Leveraging our proprietary, flexible, off-the-shelf ImmTAX (Immune mobilizing monoclonal TCRs Against X disease) platform, we are developing a deep pipeline in multiple therapeutic areas, including clinical stage programs in oncology and infectious disease, advanced preclinical programs in autoimmune disease and earlier preclinical programs across three therapeutic areas.

In 2022, we received approval for our lead product, KIMMTRAK, for the treatment of unresectable or metastatic uveal melanoma ("mUM") from the FDA, the European Commission, and other health authorities. KIMMTRAK is now approved in 39 countries for the treatment of unresectable or mUM. We have commercially launched KIMMTRAK in 30 countries globally including the United States, Germany and France through December 31, 2025, with further commercial launches planned in additional territories where KIMMTRAK is approved.

KIMMTRAK is the lead product from our ImmTAX platform and was the first approved therapy in mUM. To date, we have treated over 2,000 cancer patients with KIMMTRAK, tebentafusp, and our other ImmTAX product candidates, which we believe is the largest clinical data set of any T cell engager bispecific in solid tumors and any TCR therapeutic. Our clinical programs are being conducted with patients with a broad range of cancers including melanoma, ovarian, lung, and colorectal, among others. We believe that these tumor types have large addressable patient populations and significant unmet need. We are progressing three late-stage clinical programs within our ImmTAC (Immune mobilizing monoclonal TCRs Against Cancer) portfolio, including KIMMTRAK and PRAME-targeted brenetafusp.

Since our inception, we have focused on organizing and staffing our company, raising capital, performing research and development activities to advance our research, development and technology, and commercialization of KIMMTRAK. While we have successfully generated revenue from KIMMTRAK, which is our first marketed product, our ability to generate higher levels of revenue from other marketed products, which may never be fully developed or commercialized, depends on the successful development and regulatory approval of one or more of our product candidates and our ability to finance operations. We have raised funds through our initial public offering, private placements of our ordinary and preferred shares, debt financings, revenue and historical payments from our collaboration partners. These funds have been and are being used to fund operations and invest in activities for technology creation, drug discovery and clinical development programs, infrastructure, creation of portfolio of intellectual property and commercial and administrative support.

We have incurred significant operating losses and expect to continue to incur significant expenses and operating losses for the near future. We had net losses of $35.5 million, $51.1 million and $55.3 million, for the years ended December 31, 2025, 2024 and 2023, respectively. As of December 31, 2025, our accumulated deficit was $831.3 million. We expect to continue to incur significant and increasing expenses and to incur operating losses for the foreseeable future, as we advance our product candidates through preclinical and clinical development and seek regulatory approvals, manufacture drug product and drug supply, maintain and expand our intellectual property portfolio, as well as hire additional personnel, pay for further accounting, audit, legal, regulatory and consulting services, and pay costs associated with maintaining compliance with Nasdaq listing rules and the requirements of the SEC, director and officer liability insurance, investor and public relations activities and other expenses associated with operating as a public company.

We do not expect to generate revenue from the sale of our other product candidates unless and until we successfully complete clinical development of and obtain regulatory approval for such product candidates. As a result, we may need additional funding to support our continued operations and pursue our clinical development and growth strategy. Until we can generate sufficient revenue from product sales, if ever, we expect to finance our operations through a combination of public or private equity offerings, debt financings, government funding arrangements, collaborations and marketing and distribution and licensing arrangements. We may be unable to raise additional funds or enter into such other arrangements on favorable terms, or at all, particularly in light of recently worsening macroeconomic conditions, such as supply chain disruptions, fluctuations in interest rates and volatility in the capital markets. If we fail to raise capital or enter into such arrangements as, and when, needed, we may have to significantly delay, scale back or discontinue the development and commercialization of one or more of our programs.

Because of the numerous risks and uncertainties associated with pharmaceutical development, we are unable to predict the timing or amount of future revenues, increased expenses or when or if we will be able to achieve or maintain profitability. If we fail to become profitable or are unable to sustain profitability on a continuing basis, then we may be unable to continue our operations at planned levels and may be forced to reduce our operations.

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Recent Developments

In November 2025, we presented data at The Liver Meeting 2025, organized by the American Association for the Study of Liver Diseases, showing that IMC-I109V is generally well tolerated in all evaluated doses and exhibits pharmacodynamic effects consistent with its mechanism of action, including reduction in HBsAg levels, clearance of which is indicative of resolved hepatitis B infection. We have completed the SAD portion of the trial and will determine next steps in 2026.

In December 2025, we submitted the Clinical Trial Application for our first autoimmune candidate, IMC-S118AI (PPI x PD1), for the treatment of type 1 diabetes. We expect to dose the first patient in the Phase 1 dose escalation trial in the first half of 2026.

At the JP Morgan Healthcare Conference in January 2026, we announced our strategic priorities for the company. In the first half of 2026, we expect to complete enrollment in the registrational, advanced melanoma trial, TEBE-AM, with topline data expected as early as the second half of 2026. We are advancing multiple Phase 1/2 trials, with readouts expected from brenetafusp combinations in ovarian and lung cancer, from our PRAME half-life extended candidate (IMC-P115C), and from our HIV candidate, IMC-M113V, in the second half of 2026.

Tina St. Leger notified Immunocore of her resignation as its Chief Human Resources Officer, with her departure effective May 26, 2026. The Company is conducting a formal search process to identify a successor.

On January 30, 2026, the Company announced that Dr. David Berman, its EVP, Research and Development, will depart the Company effective February 27, 2026, to pursue another opportunity. The Company will not seek a direct replacement for Dr. Berman but will leverage its existing R&D leadership.

Components of Results of Operations

Revenue

Revenue from sale of therapies, net

Revenue from sale of therapies, net relates to the sale of KIMMTRAK following marketing approval. We recognize net revenue from sale of therapies at the point in time that control transfers to a customer, which is typically on delivery to our distributors and healthcare providers. We also operate under consignment arrangements where control passes when our distributors take KIMMTRAK out of consignment inventory. The amount of revenue recognized reflects the consideration to which we expect to be entitled, net of estimated deductions for rebates, chargebacks and product returns. These estimates consider contractual and statutory requirements, the expected payor and patient mix, sell-through data, our customers’ inventory levels, anticipated demand and the volume of customer purchase orders, internal data, and other information provided by our customers and third-party logistics providers, and in certain countries, pricing negotiations. Further information on estimates is provided under the section below headed, “Critical Accounting Estimates”.

Collaboration revenue

Historically, collaboration revenue arose under our collaboration agreements and consisted of non-refundable upfront payments, development milestone payments as well as reimbursement of certain research and development expenses. We have no continuing performance obligations under our historical collaboration agreements.

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Operating Expenses

Cost of revenue from sale of therapies

Cost of revenue from sale of therapies represents production costs including raw materials, external manufacturing costs, and other costs incurred in bringing inventories to their location and condition prior to sale. Cost of revenue from sale of therapies may also include costs related to manufacturing losses and excess or obsolete inventory costs. For example, in June 2025, we initiated a global recall for one batch of KIMMTRAK (tebentafusp) relating to an unexpected result in routine stability testing. As of the date of this Annual Report, based on all available data to date, we do not expect there will be a material impact on KIMMTRAK or our financial statements. Overheads and internal costs of revenue from sale of therapies are minimal under our manufacturing arrangements.

Research and development expenses

Research and development ("R&D") expenses consist primarily of costs incurred for current or planned investigations undertaken with the prospect of gaining new scientific or technical knowledge and understanding. R&D expenses consist primarily of employee-related costs, including salaries and share-based compensation expense, costs associated with clinical trial activities undertaken by contract research organizations ("CROs"), and external manufacturing costs associated with R&D undertaken by contract manufacturing organizations ("CMOs"), laboratory consumables, internal clinical trial expenses, payments for purchased rights and milestones in connection with third-party in-process R&D agreements, costs associated with maintaining laboratory equipment, costs associated with our R&D facilities, including a reasonable allocation of overhead costs, and reductions from expenses for R&D tax credits. R&D expenses are expensed as incurred, although the timing of expense recognition can vary with contractual and payment terms in order to determine when services are received.

R&D expenses incurred with external organizations to undertake R&D activities on our behalf typically relate to clinical programs and are assigned to the individual programs in tables further below. However, for certain preclinical programs and other research spend incurred externally, such spend is not assigned to individual programs. Internal R&D expenses primarily relate to employee-related costs, facilities, information technology used in R&D activities and laboratory consumables. Due to the cross functional expertise of our people, it is not possible to provide a breakdown of internal costs by program.

We expect our R&D expenses to increase in the future as we advance existing and future product candidates into and through clinical studies and pursue further regulatory approval. The process of conducting the necessary clinical studies to obtain regulatory approval is costly and time-consuming. We maintain our headcount at a level required to support our continued research activities and development of our product candidates. Clinical trials generally become larger and more costly to conduct as they advance into later stages. We cannot determine with certainty the timing of initiation, the duration or the completion costs of current or future preclinical studies and clinical trials of our product candidates due to the inherently unpredictable nature of preclinical and clinical development. Clinical and preclinical development timelines, the probability of success and development costs can differ materially from expectations. At this time, we cannot reasonably estimate or know the nature, timing and estimated costs of the efforts that will be necessary to complete the development of any product candidates that we develop from our programs. As a result, our R&D expenses may vary substantially from period to period based on the timing of our R&D activities.

Research and development tax credits

As a company that carries out extensive R&D activities, we benefit from the U.K. R&D tax regime. For the periods ending December 31, 2025, 2024 and 2023, we claimed credits under the Research and Development Expenditure Credit ("RDEC") program and these credits are presented as a reduction to R&D expenses.

Under the RDEC program, tax credits for qualifying R&D expenses incurred prior to April 1, 2023 are granted at a headline rate of 13% and can generate cash rebates of up to 10.5% of qualifying R&D expenses. The headline rate under the RDEC program increased from 13% to 20% on April 1, 2023 and can generate cash rebates of up to 15% (increased from 10.5%) on qualifying R&D expenses incurred from this date.

Recent amendments to the U.K. R&D tax credit regime introduced restrictions on the tax relief that can be claimed for expenses incurred on subcontracted R&D activities or externally provided workers, where such subcontracted activities are not carried out in the United Kingdom or such workers are not subject to U.K. payroll taxes, subject to limited exceptions.

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Selling, general and administrative expenses

Selling, general and administrative ("SG&A") expenses consist primarily of employee-related costs, including salaries and share-based compensation expense, for selling, corporate and other administrative and operational functions including finance, legal, human resources, commercial-related expenses, information technology, as well as a proportion of facility-related costs.

In order to support our continued commercialization and global expansion of KIMMTRAK, R&D activities and our operations as a public company, we expect that we will continue to incur selling, distribution, commercial, accounting, audit, legal, regulatory, compliance, director and officer insurance costs, as well as investor and public relations expenses. Additionally, if and as we receive further regulatory approvals of product candidates, we anticipate an increase in employee-related costs and expenses in connection with our commercial operations. We have experienced, and may continue to experience, increased employee-related costs attributable to offering and maintaining competitive salaries and other impacts due to global inflation.

Interest income

Interest income arises on cash balances and short-term money market funds. Our interest income may fluctuate depending on the movement of interest rates and our total amount of cash and cash equivalents.

Interest expense

Interest expense represents costs under our interest-bearing loans and borrowings under the effective interest method.

Foreign currency (loss) gain

Foreign currency (loss) gain arises on a variety of items, including on U.S. dollar monetary assets and liabilities held by our main operating subsidiary in the United Kingdom, including our cash and cash equivalents.

Other income (expense), net

Other income (expense), net consists primarily of unrealized gains (losses) resulting from the change in fair value of our marketable securities and also includes loan and borrowing costs and other items.

Income tax benefit (expense)

We are subject to corporate taxation in the United Kingdom and our wholly-owned subsidiaries are subject to corporate taxation in the United States, Ireland and Switzerland. Due to the nature of our business and on a consolidated basis, we have generated cumulative losses since inception. Our income tax benefit (expense) represents the sum of income taxes payable in the United States, Ireland and Switzerland, offset by movements in our deferred tax assets.

Unsurrendered tax losses are carried forward to be offset against future taxable profits. After accounting for tax credits receivable, there were accumulated tax losses available for carry forward in the United Kingdom of $525.5 million as of December 31, 2025. A full valuation allowance is recognized in respect of accumulated tax losses and other temporary differences in the United Kingdom because future profits are not sufficiently certain. There were tax losses in the United States that were generated in 2025 available for carry forward in the amount of $73.6 million. A full valuation allowance is recognized in respect to these losses and other temporary differences in the United States because future profits are not sufficiently certain.

As we generate significant net revenue from sale of therapies, we are able to benefit from the U.K.’s “patent box” regime, which allows profits attributable to revenues from patents or patented products to be taxed at a lower rate than other revenue. We have filed the patent box election for the 2023 and 2024 tax years and intend to file the patent box election for 2025 and subsequent tax years. The effective rate of tax for relevant streams of revenue for companies receiving this relief is 10%.

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Comparison of the Years ended December 31, 2025 and 2024

Revenue

The following table summarizes our total revenue (in thousands):

Year Ended December 31,

2025 2024 Increase / (decrease) % Increase / (decrease)

Revenue from sale of therapies, net

Revenue from sale of therapies, net is presented by country / region based on location of the end customer in the table below (in thousands):

Year Ended December 31,

2025 2024 Increase / (decrease) % Increase / (decrease)

For the year ended December 31, 2025, we generated net revenue from sale of therapies of $400.0 million due to the sale of KIMMTRAK, of which $257.0 million was in the United States, $131.4 million in Europe, including the impact of a net decrease in estimated reserves related to prior periods of $6.0 million, and $11.6 million in International. Revenue from the sale of therapies, net increased in the year ended December 31, 2025 as compared to December 31, 2024 due primarily to increased volume in the United States and Europe as well as global country expansion.

R&D Expenses

The following table summarizes our R&D expenses (in thousands):

Year Ended December 31,

2025 2024 Increase / (decrease) % Increase / (decrease)

External R&D expenses:

Internal R&D expenses:

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For the year ended December 31, 2025, our R&D expenses were $274.9 million, as compared to $222.2 million for the year ended December 31, 2024.

For the year ended December 31, 2025, our external R&D expenses increased by $37.6 million due to an increase in all other external clinical and preclinical costs of $36.0 million related to continued progress in the pipeline, primarily for our autoimmune programs, including clinical material manufacturing for anticipated Phase 1 initiation. In addition, R&D expenses incurred for our tebentafusp programs increased by $9.7 million as a result of continued advancement of the TEBE-AM and ATOM Phase 3 trials, and purchases of drug consumables. There was a decrease of $7.8 million in expenses incurred for our PRAME programs primarily resulting from higher costs in the year ended December 31, 2024, due to timing of manufacturing batches and purchases of drug consumables for our clinical trials, partially offset by higher costs in the year ended December 31, 2025 due to enrollment in our PRISM-MEL-301 Phase 3 clinical trial.

For the year ended December 31, 2025, our internal R&D expenses increased by $15.1 million primarily due to an increase in salaries and employee-related expenses and other internal R&D costs following the growth of our clinical and preclinical programs.

SG&A Expenses

For the year ended December 31, 2025, our SG&A expenses were $165.4 million, compared to $155.8 million for the year ended December 31, 2024, an increase of $9.6 million. The increase was primarily due to costs related to commercial and business support functions to support our growing pipeline and global commercial expansion.

Interest Income and Interest Expense

For the year ended December 31, 2025, interest income was $16.5 million compared to $25.6 million for the year ended December 31, 2024. This decrease of $9.1 million was primarily due to lower interest rates earned on our money market funds in the year ended December 31, 2025. For the year ended December 31, 2025, interest expense was $12.2 million compared to $18.8 million for the year ended December 31, 2024 and the decrease was primarily related to interest on the Pharmakon Loan which was repaid in November 2024.

Foreign Currency (Loss) Gain

For the year ended December 31, 2025, foreign currency gain was $2.2 million compared to a loss of $3.4 million for the year ended December 31, 2024. This change of $5.6 million reflects favorable exchange rate movements mainly due to the weakening of the U.S. dollar against the pound sterling and the euro in the year ended December 31, 2025.

Other Income (Expense), Net

For the year ended December 31, 2025, other income, net was $19.7 million compared to other income, net of $14.2 million for the year ended December 31, 2024. The increase was primarily related to income on our marketable securities purchased in the second quarter of 2024, including the unrealized gains resulting from the change in fair value, partially offset by lower unrealized gains due to less favorable interest rate movement in the year ended December 31, 2025.

Income Tax Benefit (Expense)

For the year ended December 31, 2025, our income tax expense was $16.4 million compared to a benefit of $1.9 million for the year ended December 31, 2024. This change of $18.3 million primarily relates to a $14.7 million deferred tax expense in 2025 for a valuation allowance on our U.S. deferred tax assets as we no longer expect to be profitable in the United States jurisdiction in the short term, due to a change in intercompany pricing arrangements implemented in the year consistent with our evolution as a company and associated reallocation of income and expenses between geographic jurisdictions that aligns with global tax authority standards.

Liquidity and Capital Resources

Sources of Liquidity

Although we have recorded revenue from the sale of therapies, we have continued to incur operating losses and cumulative negative cash flows from our operations since our inception. We have an accumulated deficit of $831.3 million as of December 31, 2025.

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Since our inception, we have funded our operations primarily with proceeds from sales of equity securities, revenue from sale of therapies, debt financings, and historical payments from collaboration partners. As of December 31, 2025 and 2024, we had cash and cash equivalents of $467.7 million and $455.7 million, respectively, and marketable securities of $396.4 million and $364.6 million, respectively. Our working capital was $750.0 million as of December 31, 2025 as compared to $717.7 million as of December 31, 2024.

In September 2022, we entered into an Open Market Sale Agreement (the "Sales Agreement") with Jefferies LLC ("Jefferies"), pursuant to which we may issue and sell ADSs, each representing one ordinary share, having an aggregate offering price of up to $250 million, from time to time, in one or more at-the-market offerings, for which Jefferies will act as sales agent and/or principal. The at-the-market facility has been registered under the Securities Act of 1933 as amended, pursuant to our Registration Statement on Form S-3ASR (File No. 333-278120). As of December 31, 2025, no issuances or sales have been made pursuant to the Sales Agreement.

In February 2024, we completed a private offering of $402.5 million aggregate principal amount of the Notes. Our net proceeds from the offering of the Notes were $389.1 million, after deducting the initial purchasers’ discounts and commissions and the offering expenses. The Notes are senior, unsecured obligations of the Company and will mature on February 1, 2030, unless earlier converted, redeemed or repurchased. The Notes will accrue interest payable semiannually in arrears on February 1 and August 1 of each year, beginning on August 1, 2024, at a rate of 2.50% per year. Part of the proceeds were used to repay in full loans outstanding under our previous loan agreement with Pharmakon.

Other than the above indebtedness, we currently have no ongoing material financing commitments, such as lines of credit or guarantees, that are expected to affect our liquidity over the next five years, other than our lease obligations and supplier purchase commitments in the normal course of business.

Cash Flows

The following table summarizes the primary sources and uses of cash and cash equivalents for each period presented (in thousands):

Year Ended December 31,

Cash and cash equivalents at beginning of the year $ 455,731 $ 442,626

Net cash (used in) provided by operating activities (10,712) 26,061

Net cash used in investing activities (16,340) (355,129)

Net cash provided by financing activities 12,371 343,881

Net foreign exchange difference on cash held 26,659 (1,708)

Cash and cash equivalents at end of the year $ 467,709 $ 455,731

Net cash used in operating activities was $10.7 million for the year ended December 31, 2025, compared to net cash provided by operating activities of $26.1 million for the year ended December 31, 2024. The decrease of $36.8 million was primarily driven by a reduction in accrued expenses and other liabilities, reflecting the timing of payments, partially offset by an increase in net revenue from sale of therapies and cash collections.

Net cash used in investing activities was $16.3 million for the year ended December 31, 2025, compared to $355.1 million for the year ended December 31, 2024. The decrease is predominantly due to higher purchases of marketable securities in the year ended December 31, 2024.

Net cash provided by our financing activities during the year ended December 31, 2025 was $12.4 million as compared to $343.9 million for the year ended December 31, 2024. The decrease was primarily due to the net cash proceeds of $389.1 million from the offering of the Notes, partially offset by the $52.1 million Pharmakon loan repayment in 2024.

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Future Capital Requirements

We expect to continue to incur significant operating losses in the foreseeable future and expect our expenses to increase in connection with our ongoing activities, particularly as we continue to commercialize KIMMTRAK in additional territories, continue our research and development programs and the advancement of our product candidates through preclinical and clinical development, and seek regulatory approval and pursue commercialization of any approved product candidates.

The amounts and timing of our actual expenditure may vary significantly depending on numerous factors. Our expenses will continue to increase if, and as, we:

•pursue further approval and commercialization of KIMMTRAK in additional indications and territories;

•continue to advance the development of our clinical trials and preclinical programs;

•continue to invest in our soluble TCR platforms to conduct research to identify novel technologies;

•change or add additional suppliers;

•add additional infrastructure to our quality control, quality assurance, legal, compliance and other groups to support our operations as we progress product candidates toward commercialization;

•seek to attract and retain skilled personnel;

•create additional infrastructure to further support our operations as a public company listed in the United States and our product development and planned future commercialization efforts;

•seek marketing approvals and reimbursement for our other product candidates;

•further develop a sales, marketing and distribution infrastructure to further commercialize any products for which we may obtain marketing approval;

•seek to identify and validate additional product candidates;

•acquire or in-license other product candidates and technologies;

•maintain, protect, defend, enforce and expand our intellectual property portfolio; and

•experience any delays, interruptions or encounter issues with any of the above, including any delays or other impacts as a result of the war in Ukraine, the conflict in the Middle East, global geopolitical tension, worsening macroeconomic conditions, including supply chain disruptions, fluctuations in interest rates, rising inflation, tariffs and other trade barriers, or health epidemics or pandemics.

Since our inception, we have raised funds from sales of equity securities, debt financing, revenue from sale of therapies and collaboration agreements. In order to maintain such levels of expenditure and our anticipated expenditure, we may raise further funds by exploring debt or equity financing, or potentially further collaborations, in the future. The amount we are able to raise from these options can vary with market conditions, including the impacts of macroeconomic conditions such as supply chain disruptions, fluctuations in interest rates and volatility in the capital markets, and our longer term strategy as a company is dependent on our ability to successfully raise such funding. Moreover, we have based our estimates on assumptions that may prove to be wrong, and we could use our available capital resources sooner than we currently expect.

We held cash and cash equivalents of $467.7 million and marketable securities of $396.4 million as of December 31, 2025. Based on our current operating plans, we expect that our existing cash and cash equivalents and marketable securities balances, along with anticipated revenue from KIMMTRAK, will enable us to fund our operating expenses and capital expenditure requirements for at least twelve months from the date of filing of this Annual Report. We have based this estimate on assumptions that may prove to be wrong, and we could use our capital resources sooner than we expect. Given our need for additional financing to support the long-term clinical development of our programs, we intend to consider additional financing opportunities when market terms are favorable to us.

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Because of the numerous risks and uncertainties associated with research, development and commercialization of pharmaceutical product candidates, we are unable to estimate the exact amount of our working capital requirements. Our future funding requirements will depend on and could increase significantly as a result of many factors, including:

•the progress, timing, scope and costs of our clinical trials, including the ability to timely initiate clinical sites, enroll subjects and manufacture soluble bispecific TCR product candidates for our ongoing, planned and potential future clinical trials;

•the time and costs required to perform R&D to identify and characterize new product candidates from our research programs;

•the time and cost necessary to obtain regulatory authorizations and approvals that may be required by regulatory authorities to execute clinical trials or commercialize our products;

•the amount of sales and other revenues from KIMMTRAK in the United States, Europe, and other regions, if approved;

•our ability to successfully commercialize our other product candidates;

•our ability to have clinical and commercial products successfully manufactured consistent with FDA, regulations of the EU and other authorities’ regulations;

•the amount of sales and other revenues from product candidates that we may commercialize, if any, including the selling prices for such potential products and the availability of adequate third-party coverage and reimbursement for patients;

•the sales and marketing costs associated with commercializing our products, if approved, including the cost and timing of building our marketing and sales capabilities;

•the cost of building, staffing and validating our manufacturing processes, which may include capital expenditure;

•the continued costs of operating as a public company;

•the time and cost necessary to respond to technological, regulatory, political and market developments;

•the costs of filing, prosecuting, defending and enforcing any patent claims and other intellectual property rights;

•the costs, associated with, and terms and timing of, any future potential acquisitions, strategic collaborations, licensing agreements or other arrangements that we may establish; and

•the inability of clinical sites to enroll patients as healthcare capacities are required to cope with natural disasters, epidemics or other health system emergencies.

A change in the outcome of any of these or other variables with respect to the development of any of our current and future product candidates could significantly change the costs and timing associated with the development and commercialization of that product candidate. Furthermore, our operating plans may change in the future, and we may need additional funds to meet operational needs and capital requirements associated with such operating plans.

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Until we can generate sufficient revenue to finance our cash requirements, which we may never do, we expect to finance our future cash needs through a combination of public or private equity offerings, debt financings, collaborations, strategic alliances, licensing arrangements and other marketing or distribution arrangements as well as grant funding. If we raise additional capital through marketing and distribution arrangements or other collaborations, strategic alliances or licensing arrangements with third parties, we may have to relinquish certain valuable rights to our product candidates, technologies, future revenue streams or research programs or grant licenses on terms that may not be favorable to us. If we raise additional capital through public or private equity offerings, the terms of these securities may include liquidation or other preferences that adversely affect our shareholders’ rights. Further, to the extent that we raise additional capital through the sale of ordinary shares or securities convertible or exchangeable into ordinary shares, our shareholders’ ownership interest will be diluted. If we raise additional capital through debt financing, it would be subject to fixed payment obligations and may be subject to covenants limiting or restricting our ability to take specific actions, such as incurring additional debt, making capital expenditures or declaring dividends. If we are unable to obtain additional funding on favorable terms when needed, we may have to delay, reduce the scope of or terminate one or more of our R&D programs or clinical trials.

Our ability to raise additional capital may also be adversely impacted by potential worsening global economic conditions and disruptions to, and volatility in, financial markets in the United States and worldwide. We are also mindful that conditions in the current macroeconomic environment could affect our ability to achieve our goals. We sell our products in countries that face economic volatility and weakness. Although we have historically collected receivables from customers in such countries, sustained weakness or further deterioration of the local economies and currencies may cause customers in those countries to be unable to pay for our products. We will continue to monitor these conditions and will attempt to adjust our business processes, as appropriate, to mitigate macroeconomic risks to our business.

Contractual Obligations

Leases and manufacturing

As part of our ongoing operations, we have material contractual lease obligations over expected lease terms of several years and expiry dates extending to 2043 primarily for our most significant facilities in the United Kingdom. These obligations and potential obligations could result in payments of up to $66.0 million. The majority of such payments represent longer-term commitments as outlined in the notes to our consolidated financial statements. The lease agreements are cancellable assuming certain conditions are met prior to expiry. We expect to continue to incur expenses for such leases for the foreseeable future. As we continue to grow, launch further products or expand our operations in other countries, we may determine that it is necessary to enter into further lease agreements, which would increase our cash outflows. Further obligations or commitments in the near term relate to our capital expenditure requirements for the purpose of improving our leased facilities. If we continue to grow, such commitments may become significant in value.

We have a number of existing manufacturing obligations, some of which relate to the manufacture of KIMMTRAK. We have similar obligations related to our earlier stage programs. These obligations and potential obligations could result in payments of up to $19.0 million, and are expected to increase as we continue to advance our pipeline in 2026 and beyond. While we have already incurred costs for commercial launches of KIMMTRAK in the United States, Europe and other territories, additional manufacturing obligations may arise in future in relation to product sales in these territories. We have also entered into third-party agreements relating to marketing and distribution of KIMMTRAK. The majority of such obligations have standard payment terms, and our level of non-cancellable commitments with such parties is not considered material. To meet demand, we may amend or enter into further agreements with CMOs or other parties which could cause our cash requirements to increase. While receipts from the sale of KIMMTRAK or other future products may fund our ongoing manufacturing and sales efforts, there can be no assurance that we will earn such revenues. In the longer term, if we received regulatory approval for our other product candidates, we would expect to incur significant commercialization expenses related to product manufacturing, sales, marketing and distribution, depending on where we choose to commercialize. We may also require additional capital to pursue in-licenses or acquisitions of other product candidates.

In addition to the above obligations, commitments and potential future cash outflows, we enter into a variety of agreements and financial commitments in the normal course of business. The terms generally provide us the option to cancel, reschedule and adjust our requirements based on our business needs, prior to the delivery of goods or performance of services. However, it is not possible to predict the amount of future payments under these agreements due to the conditional nature of our obligations and the unique facts and circumstances involved in each particular agreement.

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Financing obligations

Under the terms of our agreement with the Gates Foundation, we are required to develop, manufacture and commercialize soluble TCR bispecific therapeutic candidates targeted to mutually agreed neglected diseases, currently HIV, with the potential to treat people at an affordable price in developing countries. In the event of certain defaults by us under the agreement, the Gates Foundation has the right to sell, or require us to buy-back, any of the shareholdings of us held by the Gates Foundation. In such an event, if within 12 months after such redemption or sale, we experience a change in control at a valuation of more than 150% of the valuation used for the redemption or the sale of the shares, we have agreed to pay the Gates Foundation compensation equal to the excess of what it would have received in such transaction if it still held its shares at the time of such change of control over what it received in the sale or redemption of its shares.

In February 2024, we completed a private offering of $402.5 million aggregate principal amount of the Notes, including the exercise in full of the initial purchasers’ option to purchase up to an additional $52.5 million principal amount of Notes. Our net proceeds from the offering of the Notes were $389.1 million, after deducting the initial purchasers’ discounts and commissions and the offering expenses. The Notes are senior, unsecured obligations of the Company and will mature on February 1, 2030, unless earlier converted, redeemed or repurchased. The Notes will accrue interest payable semiannually in arrears on February 1 and August 1 of each year, beginning on August 1, 2024, at a rate of 2.50% per year. See Note 7. “Interest-bearing loans and borrowings” of the notes to our consolidated financial statements in Part IV of this Annual Report for further information.

Our Key Collaboration Agreements

BMS Collaboration

In February 2024, we entered into a clinical trial collaboration and supply agreement with BMS (the "BMS Agreement") to investigate our ImmTAC bispecific TCR candidate targeting PRAME HLA-A*02:01, brenetafusp, in combination with BMS’s nivolumab, in first-line advanced cutaneous melanoma. Under the terms of the BMS Agreement, we are sponsoring and funding the registrational Phase 3 clinical trial of brenetafusp in combination with nivolumab in first-line advanced cutaneous melanoma (PRISM-MEL-301), and BMS is providing nivolumab. No monetary consideration is transferred as a result of the BMS Agreement.

Critical Accounting Estimates

Our consolidated financial statements as of December 31, 2025 and 2024, and for the years ended 2025, 2024 and 2023 have been prepared in accordance with U.S. GAAP. The preparation of the consolidated financial statements requires us to make judgments, estimates and assumptions that affect the value of assets and liabilities—as well as contingent assets and liabilities—as reported on the balance sheet date, and revenues and expenses arising during the fiscal year.

The estimates and associated assumptions are based on information available when the consolidated financial statements are prepared, historical experience and various other factors which are believed to be reasonable under the circumstances, the results of which form the basis of making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Existing circumstances and assumptions about future developments, however, may change due to market changes or circumstances arising that are beyond our control. Hence, estimates may vary from the actual values.

The estimates and underlying assumptions are reviewed on an ongoing basis. Revisions to accounting estimates are recognized in the period in which they become known and are applied prospectively.

Expected rebate and chargeback percentage for revenue deductions

Since approval of KIMMTRAK in 2022, we have a short history of actual rebate claims or chargebacks, and such information may have limited predictive value. We use the expected value method to estimate expected rebate and chargeback percentages for revenue deductions, which considers the likelihood of a rebate or chargeback being applicable to sales. The proportion of sales subject to a rebate or chargeback is inherently uncertain and estimates are based on internal assumptions, which may change as we develop more product experience, and third-party data, which we assess for reliability and relevance.

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We are subject to state government Medicaid programs and other qualifying federal and state programs in the United States requiring rebates to be paid to participating state and local government entities, depending on the eligibility and circumstances of patients treated with KIMMTRAK after we have sold vials to specialty distributors. We are also subject to chargebacks from its specialty distributors under the 340B program in the United States, whereby qualifying hospitals are entitled to purchase KIMMTRAK at a lower price. For such sales, our specialty distributors charge back the difference between the wholesale acquisition cost and this lower price. Estimating expected rebate and chargeback percentages for revenue deductions is judgmental due to the time delay between the date of the sale to specialty distributors and the subsequent dates on which we are able to determine actual amounts of chargebacks and rebates. We form estimates of 340B chargeback deductions by analyzing sell-through data relating to the hospital mix of onward sales made by specialty distributors. For Medicaid and other rebates, we form estimates based on information obtained from claims received and other industry data, and external health coverage statistics. Judgment is applied to consider the relevance and reliability of information used to make these estimates.

Judgment has historically been made in determining expected rebate percentages for the amount of net revenue from sale of therapies in France. Rebates payable were subject to a high degree of estimation uncertainty. Our estimate of these rebates represented the difference between the expected agreed price for the commercial sale of KIMMTRAK in France, which has historically been subject to negotiation, and the initial price of tebentafusp and KIMMTRAK until we completed price negotiations in France in the first quarter of 2025. Analysis of further legislative requirements, sales volumes and the expected benefit of KIMMTRAK to patients in France was also required in the assessment of rebates payable. We applied judgement to assess internal targets, pricing information of other therapies approved for sale in France, information obtained from price negotiations of KIMMTRAK in other countries, and information connected with KIMMTRAK’s safety profile when forming our estimated rebate deduction from revenue. For other European markets, where the price is open to negotiation, judgments are made in line with expected pricing outcomes.

Our total accrued revenue deductions as of December 31, 2025 were $132.8 million, including amounts of $10.2 million for the critical estimates subject to greater estimation uncertainty and judgments described above. These amounts are included within Accrued expenses and other current liabilities in the Consolidated Balance Sheet as of December 31, 2025.

A 20% increase or decrease in estimates of expected rebate and chargeback percentages for amounts payable to governments or government agencies for the critical estimates described above would have resulted in a $2.0 million reduction or increase, in Revenue from sale of therapies, net reported in the Consolidated Statements of Operations and Comprehensive Loss for the year ended December 31, 2025. We believe our expected values of accruals reported in the Consolidated Balance Sheet are materially appropriate; however, due to the uncertainties and judgments outlined above, it is possible eventual amounts could significantly differ to these estimates. For critical estimates reported at the end of December 31, 2024, additional information including completing price negotiations in France and Germany in the year ended December 31, 2025, resulted in a change in estimate of a $6.0 million net decrease to our total accrued revenue deductions as of December 31, 2025.

Recently Issued and Adopted Accounting Pronouncements

We discuss the effect of recently issued and adopted pronouncements in Note 2 to the consolidated financial statements.

Item 7A. Quantitative and Qualitative Disclosures About Market Risk.

We are exposed to interest rate, currency, credit and liquidity risks. Our executive board oversees the management of these risks supported by a financial risk committee that advises on financial risks and the appropriate financial risk governance framework for us. The financial risk committee provides assurance to our executive board that our financial risk activities are governed by appropriate policies and procedures and that financial risks are identified, measured and managed in accordance with our policies and risk objectives. The most significant financial risks to which we are exposed include the risks discussed below.

Interest Rate Risk

Our exposure to changes in interest rates relates to investments in deposits and to changes in the interest for overnight deposits and marketable securities. Changes in the general level of interest rates may lead to an increase or decrease in the fair value of these investments.

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In February 2024, we completed a private offering of $402.5 million aggregate principal amount of the Notes, which mature on February 1, 2030, unless earlier converted, redeemed, or repurchased. The Notes accrue interest payable semiannually at a fixed rate of 2.50% per annum, commencing August 1, 2024. Issuance costs totaling $13.4 million are being amortized as interest expense at an effective rate of 3.06% over the life of the Notes. Given the fixed interest rate, the Company is not subject to interest rate risk with respect to these Notes. However, changes in market interest rates could affect the fair value of the Notes and the price of our ADSs, influencing the decision of noteholders to convert their Notes.

We are currently not subject to interest rate risks related to any other liabilities shown in the Consolidated Balance Sheets.

Currency Risk

Foreign currency risk is the risk that the fair value or future cash flows of a financial instrument will fluctuate because of changes in foreign exchange rates. Our exposure to the risk of changes in foreign exchange rates relates primarily to fluctuations in value of foreign currency cash and cash equivalents balances held by our main operating subsidiary in the United Kingdom, our operating activities in foreign subsidiaries, and outsourced supplier agreements denominated in currencies other than functional currency. We minimize foreign currency risk by maintaining cash and cash equivalents of each currency at levels sufficient to meet foreseeable expenditure to the extent practical.

Our cash and cash equivalents were $467.7 million and $455.7 million as of December 31, 2025 and 2024, respectively. As of December 31, 2025, 81% of our cash and cash equivalents were held by our U.K. operating subsidiary, of which 46% were denominated in U.S. dollars, 41% were denominated in pounds sterling and 13% were denominated in euros. All of our marketable securities were held by our U.K. parent company and were denominated in U.S. dollars. The remainder of our cash and cash equivalents are held across our other subsidiaries and denominated in a mix of operating currencies. Changes in exchange rates had an impact on U.S. dollar cash and cash equivalents balances held by our main operating subsidiary in the United Kingdom, which resulted in foreign exchange gains and losses in the Consolidated Statements of Operations and Comprehensive Loss due to the appreciation and depreciation of the subsidiary’s U.S. dollars in pounds sterling terms. Further movements in exchange rates or returns to previous exchange rate levels have caused, and may continue to cause, material fluctuations or equivalent losses in the Consolidated Statements of Operations and Comprehensive Loss.

A five percentage point increase in exchange rates would reduce the carrying value of net financial assets and liabilities held in foreign currencies as of December 31, 2025 by $6.5 million and as of December 31, 2024 by $6.0 million. A five percentage point decrease in exchange rates would increase the carrying value of net financial assets and liabilities held in foreign currencies at December 31, 2025 by $6.5 million and as of December 31, 2024 by $6.0 million.

Credit Risk

We are exposed to credit risk from our operating activities, primarily accounts receivable, cash and cash equivalents, and marketable securities held with banks and financial institutions. Cash and cash equivalents and marketable securities are maintained with high-quality financial institutions in the United Kingdom and United States. We are also potentially subject to concentrations of credit risk in our accounts receivable with respect to amounts owed by a limited number of entities comprising our customer base. Our exposure to credit losses is low, however, owing largely to the credit quality of our distributors, and other customers, the significant majority of which are considerably larger than us.

We continually monitor our positions with, and the credit quality of, the financial institutions and corporations, which are counterparts to our financial instruments and do not anticipate non-performance. The maximum default risk corresponds to the carrying amount of the financial assets shown in the Consolidated Balance Sheets. We monitor the risk of a liquidity shortage. The main factors we consider are the maturities of financial assets as well as expected cash flows from equity measures.

Item 8. Financial Statements and Supplementary Data

Our consolidated financial statements required to be filed pursuant to this Item 8 are appended at the end of this Annual Report. An index of those financial statements is found in Item 15 of Part IV of this Annual Report.

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

None.

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Item 9A. Controls and Procedures

Disclosure Controls and Procedures

We maintain “disclosure controls and procedures,” as defined in Rules 13a-15(e) and 15d-15(e) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), that are designed to ensure that information required to be disclosed by us in the reports that we file or submit under the Exchange Act is recorded, processed, summarized and reported, within the time periods specified in the SEC’s rules and forms, and is accumulated and communicated to our management, including our Chief Executive Officer and Chief Financial Officer, as appropriate to allow timely decisions regarding required disclosure.

Our management, with the participation of our Chief Executive Officer and Chief Financial Officer, has evaluated the effectiveness of our disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) as of December 31, 2025. Based on such evaluation, our Chief Executive Officer and Chief Financial Officer have concluded that, as of December 31, 2025, our disclosure controls and procedures were effective.

Management’s Annual Report on Internal Control Over Financial Reporting

Our management is responsible for establishing and maintaining adequate internal control over financial reporting. Exchange Act Rules 13a-15(f ) and 15d-15(f ) define this as a process designed by, or under the supervision of, our Chief Executive Officer and our Chief Financial Officer and effected by the Board of Directors, management and other personnel, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements in accordance with U.S. GAAP.

Due to its inherent limitations, internal control over financial reporting may not prevent or detect all misstatements. Furthermore, projections of any evaluation of the effectiveness of internal controls to future periods may prove invalid due to changes in our circumstances and the risk that compliance with policies, procedures and controls is not sustained.

Management has assessed the effectiveness of internal control over financial reporting as of December 31, 2025 based on the Internal Control — Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO). Based on this assessment, management has concluded that our internal control over financial reporting as of December 31, 2025 was effective.

Our independent registered public accountant, Deloitte LLP, who audited the consolidated financial statements as of and for the year ended December 31, 2025 included in this annual report, has audited the effectiveness of the Company’s internal control over financial reporting as of December 31, 2025. Deloitte LLP’s report is included below.

Report of Independent Registered Public Accounting Firm

To the Shareholders and Board of Directors of Immunocore Holdings plc:

Opinion on Internal Control Over Financial Reporting

We have audited the internal control over financial reporting of Immunocore Holdings plc and subsidiaries (the “Company”) as of December 31, 2025, 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 Company maintained, in all material respects, effective internal control over financial reporting as of December 31, 2025, based on criteria established in Internal Control — Integrated Framework (2013) issued by COSO.

We have also audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (PCAOB), the consolidated financial statements as of and for the year ended December 31, 2025, of the Company and our report dated February 25, 2026, expressed an unqualified opinion on those financial statements.

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Basis for Opinion

The Company’s management is responsible for maintaining effective internal control over financial reporting and for its assessment of the effectiveness of internal control over financial reporting, included in the accompanying Management’s Annual Report on Internal Control Over Financial Reporting. Our responsibility is to express an opinion on the Company’s internal control over financial reporting based on our audit. We are a public accounting firm registered with the 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 audit in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether effective internal control over financial reporting was maintained in all material respects. Our audit included obtaining an understanding of internal control over financial reporting, assessing the risk that a material weakness exists, testing and evaluating the design and operating effectiveness of internal control based on the assessed risk, and performing such other procedures as we considered necessary in the circumstances. We believe that our audit provides a reasonable basis for our opinion.

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 (1) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions of the assets of the company; (2) 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 (3) 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.

/s/ Deloitte LLP

Cambridge, United Kingdom

February 25, 2026

Changes in Internal Control Over Financial Reporting

There has been no change in our internal control over financial reporting (as defined in Rules 13a-15(f) of the Exchange Act) that occurred during the quarter ended December 31, 2025 that has materially affected, or is reasonably likely to materially affect, our internal control over financial reporting.

Item 9B. Other Information

Insider Trading Arrangements

During the three months ended December 31, 2025, none of our directors and officers (as defined in Rule 16a-1(f) under the Exchange Act) adopted or terminated a “Rule 10b5-1 trading arrangement” or “non-Rule 10b5-1 trading arrangement,” as each term is defined in Item 408(a) of Regulation S-K.

Item 9C. Disclosure Regarding Foreign Jurisdictions that Prevent Inspections

Not applicable

PART III

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Item 10. Directors, Executive Officers and Corporate Governance

The information required by this item is incorporated by reference to our Proxy Statement for our 2026 Annual General Meeting of Shareholders to be filed with the SEC within 120 days after the end of the fiscal year ended December 31, 2025.

We have adopted a Code of Business Conduct and Ethics that is applicable to all of our employees, officers and directors. This includes our principal executive officer, principal financial officer and principal accounting officer or controller or persons performing similar functions. If we make any amendment to the Code of Business Conduct and Ethics or grant any waivers, including any implicit waiver, to the principal executive officer, principal financial officer and principal accounting officer or controller or persons performing similar functions from a provision of the code of ethics, we will disclose the nature of such amendment or waiver on our website to the extent required by the rules and regulations of the SEC. The Code of Business Conduct and Ethics is available on our website at https://www.immunocore.com/investors/corporate-governance/governance-documents. Information contained on, or that can be accessed through, our website does not constitute a part of this Annual Report and is not incorporated by reference herein.

We have also adopted an insider trading policy governing the purchase, sale and other dispositions of our securities by our directors, officers and employees that we believe is reasonably designed to promote compliance with insider trading laws, rules and regulations, and any applicable listing standards. A copy of our insider trading policy is filed as Exhibit 19.1 to this Annual Report on Form 10-K.

Item 11. Executive Compensation

The information required by this item is incorporated by reference to our Proxy Statement for our 2026 Annual General Meeting of Shareholders to be filed with the SEC within 120 days after the end of the fiscal year ended December 31, 2025.

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

The information required by this item is incorporated by reference to our Proxy Statement for our 2026 Annual General Meeting of Shareholders to be filed with the SEC within 120 days after the end of the fiscal year ended December 31, 2025.

Item 13. Certain Relationships and Related Transactions, and Director Independence

The information required by this item is incorporated by reference to our Proxy Statement for our 2026 Annual General Meeting of Shareholders to be filed with the SEC within 120 days after the end of the fiscal year ended December 31, 2025.

Item 14. Principal Accountant Fees and Services

The information required by this item is incorporated by reference to our Proxy Statement for our 2026 Annual General Meeting of Shareholders to be filed with the SEC within 120 days after the end of the fiscal year ended December 31, 2025.

PART IV

Item 15. Exhibits and Financial Statement Schedules

Incorporation by Reference

ExhibitNumber Description Schedule/Form FileNumber Exhibit Filing Date

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21.1* Subsidiaries of the Registrant

23.1* Consent of Deloitte LLP

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101.SCH Inline XBRL Taxonomy Extension Schema Document

*Filed herewith.

**This certification is deemed furnished, not "filed" for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), or otherwise subject to the liability of that section, nor shall it be deemed incorporated by reference into any filing under the Securities Act of 1933, as amended, or the Exchange Act.

†Certain portions of this exhibit (indicated by asterisks) have been redacted in accordance with Regulation S-K, Item 601(b)(10).

#Indicates a management contract or any compensatory plan, contract or arrangement.

Item 16. Form 10-K Summary

None.

SIGNATURES

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

IMMUNOCORE HOLDINGS PLC

By: /s/ Bahija Jallal

Bahija Jallal, Ph.D.

Chief Executive Officer

(Principal Executive Officer)

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POWER OF ATTORNEY

Each of the undersigned officers and directors of Immunocore Holdings plc, hereby constitutes and appoints Bahija Jallal and Travis Coy, their true and lawful attorney-in-fact and agent, for them and in their name, place and stead, in any and all capacities, to sign their name to any and all amendments to this Report on Form 10-K, and other related documents, and to cause the same to be filed with the Securities and Exchange Commission, granting unto said attorneys, full power and authority to do and perform any act and thing necessary and proper to be done in the premises, as fully to all intents and purposes as the undersigned could do if personally present, and the undersigned for himself hereby ratifies and confirms all that said attorney shall lawfully do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Exchange Act of 1934, this Annual Report on Form 10-K has been signed below by the following persons on February 25, 2026 on behalf of the registrant and in the capacities indicated.

SIGNATURE TITLE DATE

Bahija Jallal, Ph.D.

Travis Coy

John Goll

/s/ Professor Sir John Bell Chairman of the Board of Directors February 25, 2026

Professor Sir John Bell

/s/ Roy S. Herbst, M.D., Ph.D. Director February 25, 2026

Roy S. Herbst, M.D., Ph.D.

/s/ Siddharth Kaul Director February 25, 2026

Siddharth Kaul

/s/ Dr. William Pao, M.D., Ph.D. Director February 25, 2026

Dr. William Pao, M.D., Ph.D.

/s/ Kristine Peterson Director February 25, 2026

Kristine Peterson

/s/ Professor Sir Peter Ratcliffe Director February 25, 2026

Professor Sir Peter Ratcliffe

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INDEX TO CONSOLIDATED FINANCIAL STATEMENTS

Page

Report of Independent Registered Public Accounting Firm (PCAOB ID 1147) F-2

Consolidated Balance Sheets as of December 31, 2025 and 2024 F-4

Notes to the Consolidated Financial Statements F-9

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REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

To the shareholders and the Board of Directors of Immunocore Holdings plc

Opinion on the Financial Statements

We have audited the accompanying consolidated balance sheets of Immunocore Holdings plc and subsidiaries (the “Company”) as of December 31, 2025 and 2024, the related consolidated statements of operations and comprehensive loss, shareholders’ equity, and cash flows, for each of the three years in the period ended December 31, 2025, and the related notes (collectively referred to as the “financial statements”). In our opinion, the financial statements present fairly, in all material respects, the financial position of the Company as of December 31, 2025 and 2024, and the results of its operations and its cash flows for each of the three years in the period ended December 31, 2025, in conformity with accounting principles generally accepted in the United States of America.

We have also audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (PCAOB), the Company’s internal control over financial reporting as of December 31, 2025, based on criteria established in Internal Control — Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission and our report dated February 25, 2026, expressed an unqualified opinion on the Company’s internal control over financial reporting.

Basis for Opinion

These financial statements are the responsibility of the Company’s management. Our responsibility is to express an opinion on the Company’s financial statements based on our audits. We are a public accounting firm registered with the 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 audit to obtain reasonable assurance about whether the financial statements are free of material misstatement, whether due to error or fraud. Our audits included performing procedures to assess the risks of material misstatement of the 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 financial 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 financial statements. We believe that our audits provide a reasonable basis for our opinion.

Critical Audit Matter

The critical audit matter communicated below is a matter arising from the current-period audit of the financial statements that was communicated or required to be communicated to the audit committee and that (1) relates to accounts or disclosures that are material to the financial statements and (2) involved our especially challenging, subjective, or complex judgments. The communication of critical audit matters does not alter in any way our opinion on the 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.

Revenue from sale of therapies, net – Deductions and accruals for government rebates — Refer to Notes 2 and 3 to the financial statements

Critical Audit Matter Description

As more fully disclosed in the Significant Accounting Policies note to the financial statements, the Company recognizes revenue from sale of therapies at the net sales price, which includes deductions for which reserves are established. These deductions include rebates, chargebacks, levies, other customer fees and product returns.

Government rebates are provided in relation to programs in certain jurisdictions in which the Company operates. In certain of these jurisdictions, management is required to make significant assumptions and judgments to estimate the government rebate claims related to sales in the respective geographies. These assumptions and judgements include:

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(1)pricing in geographies where negotiations are ongoing with the respective governments;

(2)amounts where the government has the potential to clawback additional costs based on volume of sales, government budgets or through renegotiation of pricing; and

(3)future claims yet to be received, related to products sold in the reporting period.

These estimates include consideration of internal forecasts of the patient and distributor mix, information obtained from historic claims received and other industry data, and external health coverage statistics.

We identified deductions and accruals for government rebates in certain jurisdictions as a critical audit matter given the complexity involved in determining the significant assumptions and judgments used in estimating the anticipated government rebate claims, which in turn led to a high degree of auditor professional judgment and increased extent of audit effort in auditing such estimates.

How the Critical Audit Matter Was Addressed in the Audit

Our audit procedures related to the government rebates, included the following, among others:

- We tested the effectiveness of controls over management's processes to account for the deductions and accruals associated with government rebates, including controls over determining the underlying assumptions and key inputs into the Company’s process to calculate government rebate adjustments.

- We inspected contractual documents and communications with government agencies and third-party advisors associated with the government rebates, and evaluated the consistency of the estimation methodology with the Company's obligations under such contractual documents and communications.

- We tested the mathematical accuracy of the Company's calculation of the estimates for government rebates.

- We evaluated whether the accounting treatment for the anticipated government rebate claims is consistent with the relevant accounting standard, ASC 606 Revenue Recognition.

- We performed the following procedures to evaluate the significant assumptions and judgments used by management to estimate the government rebate claims:

(i)stress tested certain assumptions and subjective inputs for the government rebates to evaluate the impact on the estimate;

(ii) evaluated management's estimates by using a combination of internal and third-party data, and insights from pricing experts to develop our own independent estimates; and

(iii) assessed whether the actual rebate payments were made in the year and were in line with the relevant contractual terms.

/s/ Deloitte LLP

Cambridge, United Kingdom

February 25, 2026

We have served as the Company’s auditor since 2023.

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Immunocore Holdings Plc

Consolidated Balance Sheets

(in thousands, except share and per share data)

Assets

Current assets

Prepaid expenses and other current assets 50,055 41,033

Tax receivable 1,815 —

Operating lease right of use assets, net 38,783 37,643

Deferred tax assets, net — 14,790

Liabilities and shareholders’ equity

Current liabilities

Accrued expenses and other current liabilities 219,744 185,534

Deferred revenue, current 583 —

Operating lease liabilities, current 2,006 1,547

Deferred revenue, non-current 4,858 5,434

Operating lease liabilities, non-current 41,556 40,162

Commitments and contingencies (Note 14)

Shareholders’ equity

Accumulated other comprehensive loss (28,084) (33,763)

The accompanying notes form an integral part of these consolidated financial statements.

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Immunocore Holdings Plc

Consolidated Statements of Operations and Comprehensive Loss

(in thousands, except share and per share data)

Year Ended December 31,

Revenue:

Cost and operating expenses:

Cost of revenue from sale of therapies (5,087) (2,731) (1,037)

Other income (expense):

Other comprehensive income:

Exchange differences on translation of foreign operations 5,679 2,498 18,412

Basic and diluted net loss per share $ (0.71) $ (1.02) $ (1.13)

The accompanying notes form an integral part of these consolidated financial statements.

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Immunocore Holdings Plc

Consolidated Statements of Shareholders’ Equity

(in thousands, except share data)

Shares Amount Shares Amount AdditionalPaid-in Capital

Other comprehensive income — — — — — — 18,412 18,412

Issuance of ordinary shares, net — — — — — — — —

Share-based compensation expense — — — — 32,469 — — 32,469

Other comprehensive income — — — — — — 2,498 2,498

Share-based compensation expense — — — — 34,196 — — 34,196

Other comprehensive income — — — — — — 5,679 5,679

Share-based compensation expense — — — — 37,781 — — 37,781

The accompanying notes form an integral part of these consolidated financial statements.

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Immunocore Holdings Plc

Consolidated Statements of Cash Flows

(in thousands)

Year Ended December 31,

Cash flows from operating activities

Adjustments for:

Unrealized foreign exchange losses (gains) (6,385) 599 13,827

Unrealized gains on marketable securities (19,728) (14,577) —

Loss on loan extinguishment — 3,853 —

Changes in assets and liabilities:

Decrease in deferred revenue (387) (1) (8,013)

Decrease in operating lease liabilities (2,093) (1,648) (2,226)

Decrease in other operating liabilities — — (1,353)

Net cash (used in) provided by operating activities (10,712) 26,061 2,940

Cash flows from investing activities

Proceeds from sale of property, plant and equipment — 44 —

Proceeds from sale of marketable securities 18,000 — —

Purchase of property, plant and equipment (4,340) (5,173) (5,425)

Cash flows from financing activities

Proceeds from issue of ordinary shares, net — — —

Loan repayments — (50,000) —

Debt prepayments and extinguishments — (2,061) —

Non-current interest-bearing loan received — 402,500 —

Debt issuance payments — (13,358) —

Supplemental cash flow information

Cash paid for income taxes, net (4,643) (510) (977)

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The accompanying notes form an integral part of these consolidated financial statements.

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Immunocore Holdings Plc

Consolidated Notes to the Financial Statements

1. Description of business

Immunocore Holdings plc (collectively with its subsidiaries, the “Company”) is a public limited company incorporated in England and Wales and has the following wholly owned subsidiaries: Immunocore Limited, Immunocore LLC, Immunocore Commercial LLC, Immunocore Ireland Limited, Immunocore GmbH, and Immunocore Nominees Limited with operations based primarily in the United Kingdom and United States. The Company is pioneering and delivering transformative immunomodulating medicines to radically improve outcomes for patients with cancer, infectious diseases, and autoimmune diseases. Leveraging its proprietary, flexible, off-the-shelf ImmTAX (Immune mobilizing monoclonal TCRs Against X disease) platform, the Company’s pipeline includes clinical and preclinical programs in oncology, infectious diseases, and autoimmune diseases.

In January and April 2022, the Company received approval from the U.S. Food and Drug Administration ("FDA") and European Commission, ("EC"), respectively, for its lead product, KIMMTRAK, for the treatment of unresectable or metastatic uveal melanoma. The Company has subsequently received approvals in further territories, and continues to launch and seek approvals in additional territories. KIMMTRAK is now approved in 39 countries and the Company has commercially launched the product in 30 countries, including the United States, Germany and France, among other territories.

2. Summary of significant accounting policies

Basis of presentation

The Company’s consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States ("U.S. GAAP") for the fiscal years ended December 31, 2025, 2024, and 2023 and include the financial results of all wholly-owned subsidiaries. Intercompany transactions and balances have been eliminated upon consolidation and the consolidated financial statements are presented in U.S. dollars.

Use of estimates

The preparation of the consolidated financial statements in conformity with U.S. GAAP requires management to make judgments, estimates and assumptions. These judgments, estimates and assumptions affect the reported assets and liabilities as well as income and expenses in the financial period.

The estimates and associated assumptions are based on information available when the consolidated financial statements are prepared, historical experience and various other factors which are believed to be reasonable under the circumstances, the results of which form the basis of making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources.

Existing circumstances and assumptions about future developments, however, may change due to market changes or circumstances arising that are beyond the Company’s control. Actual results could differ from those estimates. Estimates are primarily made in relation to revenue recognition, operating lease incremental borrowing rates, share-based compensation expense, clinical accruals and deferred tax asset valuation allowances.

Foreign currencies

The reporting currency of the Company is the U.S. dollar. Effective January 1, 2024, the Company’s ultimate parent adopted the U.S. dollar as its functional currency. Prior to January 1, 2024, the functional currency of the Company’s ultimate parent was the British pound sterling. The functional currency of the Company’s ultimate parent and each subsidiary is based on the currency of the economic environment in which they operate. The change in functional currency of the Company’s ultimate parent is due to a change in the economic facts and circumstances of the entity due to the increased exposure to the U.S. dollar primarily as a result of the increased cash flows related to financing and investing activities that are now expected to occur going forward in this entity. The effect of the change in functional currency for the Company’s ultimate parent was applied prospectively in the Consolidated Financial Statements effective January 1, 2024.

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Upon consolidation, assets and liabilities of each subsidiary with a functional currency that differs to the Company’s ultimate parent are translated into U.S. dollars at period-end exchange rates, and revenues and expenses are translated into U.S. dollars using average exchange rates for each reporting period. Translation adjustments are reflected as other comprehensive income (loss).

Revenues

Pursuant to Accounting Standards Codification Topic 606 ("ASC 606"), the Company recognizes revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. To determine revenue recognition for agreements, the Company performs the following five steps: (i) identifying the contract with a customer, (ii) identifying the performance obligations in the contract, (iii) determining the transaction price, (iv) allocating the transaction price to the performance obligations, and (v) recognizing revenue when, or as, an entity satisfies a performance obligation. The Company only applies the five-step model to contracts when it is probable that the entity will collect the consideration to which it is entitled in exchange for the goods or services it transfers to the customer.

At contract inception, the Company identifies the goods or services promised within each contract, assesses whether each promised good or service is distinct and determines those that are performance obligations. The Company recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when the performance obligation is satisfied.

Revenue from sale of therapies, net

Revenue from sale of therapies, net relates to the sale of KIMMTRAK following marketing approval and the sale of tebentafusp under a compassionate use and an early access program in France up to September 2022. The Company recognizes revenue at the point in time that control transfers to a customer, which is typically on delivery. The Company also operates under consignment arrangements where control passes when the Company’s distributors take KIMMTRAK out of consignment inventory. The amount of revenue recognized under its arrangements reflects the consideration to which the Company expects to be entitled, net of estimated deductions for rebates, chargebacks and product returns. Estimated revenue deductions are updated at the end of each reporting period using the latest available data. The Company considers whether any part of amounts expected to be received should be constrained to ensure that it is probable that a significant reversal in the cumulative revenue recognized will not occur.

Rebates: Rebates consist of Medicaid and other governmental rebates in the U.S. and other similar programs in Europe. These reserves are recorded as a reduction to revenue in the same period the related revenue is recognized. The Company's estimates are based on current pricing and historical data, updated at each reporting period to reflect actual claims received. For markets where the price is open to negotiation, judgments are made in line with expected pricing outcomes.

Chargebacks: Chargebacks for discounts represent the Company’s estimated obligations resulting from contractual commitments for specialty distributors to sell KIMMTRAK to qualifying hospitals at a lower price. For such sales, the specialty distributors charge back the difference between the wholesale acquisition cost and this lower price. The Company estimates chargeback deductions by analyzing sell-through data relating to the hospital mix of onward sales made by specialty distributors.

Product returns: The Company estimates the amount of its product sales that may be returned by its customers and records this in the period the related revenue is recognized. The Company bases product return liabilities on quantitative information provided by the Company’s distributors.

The Company’s main customers in the United States and Europe are its distributors. These distributors are invoiced at contractual list prices with standard payment terms typically between one and two months. When the Company has the right to offset chargebacks against accounts receivable and the parties have agreed to settle the payments net, chargebacks are recorded as a reduction in accounts receivable. Other chargebacks, rebates and deductions are recognized in Accrued expenses and other current liabilities in the Consolidated Balance Sheets.

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In certain countries, the Company’s customers are hospitals and healthcare providers, where KIMMTRAK is sold through an agent acting on the Company’s behalf. Revenue from sale of therapies, net also includes amounts for partnered revenue, which is recognized on delivery and transfer of title to Medison Pharma Ltd ("Medison") and Er-Kim Pharmaceuticals Bulgaria EOOD ("Er-Kim") the Company’s exclusive distributors in certain countries outside the United States. From December 31, 2025, we have combined Product revenue, net and Pre-product revenue, net into Revenue from sale of therapies, net in order to simplify our presentation.

Collaboration revenue

The Company analyzes its collaboration agreements to assess whether they are within the scope of ASC Topic 808, Collaborative Arrangements (“ASC 808”) to determine whether such arrangements involve joint operating activities performed by parties that are both active participants and are exposed to significant risks and rewards that are dependent on the commercial success of such activities. It was determined that the Company's historical collaboration agreements were not in the scope of ASC 808. The Company concluded that all aspects of the arrangements represented a transaction with a customer, and therefore, were accounted for within the scope of ASC 606. Pursuant to ASC 606, a customer is a party that has contracted with an entity to obtain goods or services that are an output of the entity’s ordinary activities in exchange for consideration. An entity recognizes revenue when its customer obtains control of promised goods or services, in an amount that reflects the consideration which the entity expects to receive in exchange for those goods or services. The Company determines the units of account within the collaboration agreement utilizing the guidance in ASC 606 to determine which promised goods or services are distinct. In order for a promised good or service to be considered distinct under ASC 606, the customer can benefit from the good or service either on its own or together with other resources that are readily available to the customer (i.e., the good or service is capable of being distinct), and the entity’s promise to transfer the good or service to the customer is separately identifiable from other promises in the contract (i.e., the promise to transfer the good or service is distinct within the context of the contract).

Under its historical collaboration agreements, the Company granted rights to technology with respect to the development of specified targets and the commercialization of future product candidates for such targets. In addition, the Company was required to perform R&D services, participate on a joint steering committee and the agreements also provided parties with the option to obtain exclusive rights to the associated intellectual property license. The Company assesses whether each promised good or service is distinct for the purpose of identifying the performance obligations in the contract. The Company determined that these promises represented specialized, combined performance obligations, which were satisfied over time. Further, the Company determined that their collaborators cannot benefit from the intellectual property licenses separately from the R&D activities and participation on the joint steering committee because these services are specialized and rely on the Company’s expertise such that these activities are highly interrelated and therefore not distinct.

The Company estimates the transaction price based on the amount it expects to be entitled to for transferring the promised goods or services in the contract and may include fixed and variable consideration. At the inception of each arrangement that includes variable consideration, the Company evaluates the amount of potential payment and the likelihood that the underlying constraint will be released. Variable consideration is included in the transaction price only to the extent that it is probable that a significant reversal in the amount of the cumulative revenue recognized will not occur in a future period.

Revenue is recognized using an estimate of percentage completion which takes into consideration the estimated timelines required to satisfy the performance obligation and the time taken since program nomination.

Deferred revenue

The Company’s deferred revenue as of December 31, 2025 and 2024 is related to a revenue partnership with Medison relating to the supply and distribution of KIMMTRAK and will be classified within revenue from sale of therapies, net in accordance with ASC 606. The Company’s deferred revenue relates to a non-refundable upfront receipt from Medison under an amended agreement entered into in November 2022. The Company determined that this receipt relates to the distribution of KIMMTRAK in South America and assessed that the Company has a single performance obligation to provide KIMMTRAK to Medison for onward sale under an exclusive distribution license. The deferred revenue is expected to be released with the sale of products following regulatory approval in the territory.

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Accounts receivable

Accounts receivable includes amounts invoiced or contractually accrued where only the passage of time is required before payment is received under the Company’s revenue arrangements. Such receivables principally relate to KIMMTRAK sales. An allowance for lifetime expected credit losses on accounts receivable is measured using historical credit loss experience, conditions at the end of each reporting period, and reasonable and supportable forecasts that affect collectability. Expected credit losses at the end of December 31, 2025 and 2024 were immaterial.

Inventory

Inventory includes KIMMTRAK manufactured for commercial sale, items in the process of being manufactured for sale, and materials to be used in the manufacturing process for such sale. The principal costs in manufacturing the Company’s inventory are raw materials, external manufacturing costs, and other costs incurred in bringing inventory to its location and condition prior to sale.

Inventory is recorded at weighted average cost and presented as an asset in the Consolidated Balance Sheets at the lower of cost and net realizable value. The Company assesses whether an expense should be recognized as a result of writing down inventory values at each reporting period for excess or obsolete inventory at risk of expiry. Such expenses are recorded as a component of Cost of revenue from sale of therapies in the Consolidated Statements of Operations and Comprehensive Loss in the period during which they are first identified.

The Company records inventory costs for potential products within R&D expenses until regulatory approval is considered probable, after which, the Company capitalizes subsequent costs related to the production of inventories. Certain inventory can be used for clinical purposes or for commercial products, and the Company records such items within R&D expenses at the point that the vials are assigned for clinical use.

Cost of revenue from sale of therapies

Cost of revenue from sale of therapies represents production costs including raw materials, external manufacturing costs, and other costs incurred in bringing inventory to its location and condition prior to sale. Overheads and internal costs of revenue from sale of therapies are minimal under the Company's manufacturing arrangements. Cost of revenue from sale of therapies may also include write-off costs and provisions related to excess or obsolete inventory.

Research and development ("R&D") expense

R&D costs are expensed as incurred and include (i) employee-related expenses, including salaries, benefits, travel and share-based compensation expense for employees engaged in R&D functions; (ii) external R&D expenses incurred under arrangements with third parties, such as contract research organization ("CRO") agreements, investigational sites and consultants; (iii) the cost of acquiring, developing and manufacturing clinical study materials, including the cost of consultants and contract manufacturing organization ("CMO"); (iv) costs associated with preclinical and clinical activities and regulatory operations; (v) costs incurred in development of intellectual property, (vi) and depreciation and R&D facilities costs.

The Company estimates accrued expenses at each balance sheet date based on facts and circumstances known at that time. These estimates are based on reviews of open contracts, reports provided by the CROs and CMOs and internal reviews to estimate the level of service performed and the associated cost incurred for those services when the Company has not yet been invoiced or otherwise notified of the actual cost. In accruing clinical trial expenses, the Company estimates the time period over which services will be performed and the level of effort to be expended in each period. If the actual timing of the performance of services or the level of effort varies from the estimate made, the expense is adjusted accordingly. Where payments made to CROs or other parties exceed the level of services provided, a prepayment is recorded in the Consolidated Balance Sheets.

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Share-based compensation

The Company operates equity-settled, share-based compensation plans whereby employees and directors are granted restricted share units ("RSUs") or options to purchase shares in the Company. The fair value of grants is expensed over the vesting period, which is the period in which the services are received. The majority of the Company’s awards have graded vesting schedules, and the expense for these awards is recognized over the requisite service period for each separate vesting portion as if the grant, in substance, represented multiple awards. The grant date fair value of RSUs is based on the market value of our shares on the date of grant.The grant date fair value of options is calculated using the Black Scholes valuation model.

Estimation of the fair value of options requires judgment, including assumptions about the expected term of share-based options and expected volatility, which are used to determine the fair value of the Company’s options granted. The expected term is based on the Company’s assessment of the period within which participants are expected to exercise options, which requires consideration of employee groups, expected employee service, and other internal factors, and the degree to which these are expected to shorten the term of options in comparison to contractual expiry dates. Estimated expected volatility is based on the Company’s share price volatility since its initial public offering. The expected volatility reflects the assumption that the historical volatility over a period similar to the life of the awards is indicative of future trends, which may not necessarily be the actual outcome.

The Company assumes no dividend payments for the purposes of estimating fair value and uses a zero-coupon U.S. Treasury yield curve applicable for the period of the expected term to form an estimate of the risk-free rate.

Forfeitures expected to occur for options and RSUs are estimated by considering both market and company-specific data and the available internal information at the end of each reporting period.

Income tax

Income tax includes components of current and deferred tax and is recognized in the Consolidated Statements of Operations and Comprehensive Loss.

Current tax is the expected tax payable or receivable on the taxable income or loss for the current or prior periods using tax rates enacted at the balance sheet date.

Deferred tax assets and liabilities are recognized for the expected future tax consequences of temporary differences between the financial statement carrying amount and the tax bases of assets and liabilities at the applicable tax rates and for operating loss and tax credit carryforwards. A valuation allowance reduces deferred tax assets in the Consolidated Balance Sheets to reflect the amount that is more likely than not to be realized. The Company evaluates the realizability of its deferred tax assets at each reporting period and adjusts the valuation allowance accordingly, considering income forecasts, availability of carrybacks, taxable temporary differences and other factors affecting the realization of deferred tax assets.

The Company accounts for uncertain tax positions in accordance with the provisions of ASC 740. When uncertain tax positions exist, the Company recognizes the tax benefit of tax positions to the extent that the benefit will more likely than not be realized. The determination as to whether the tax benefit will more likely than not be realized is based upon the technical merits of the tax position as well as consideration of the available facts and circumstances. As of December 31, 2025 and 2024, the Company has not recorded any provision for uncertain tax positions.

Changes in the Company’s estimate of income tax positions relating to the more-likely-than-not threshold are recognized in the first subsequent period following the threshold being met or ceasing to be met.

R&D expenditure credits

The Company receives R&D expenditure credits to compensate for its research activities, which are recognized when it is more likely than not the Company will meet the terms for receiving and realizing the benefit of the credits. Recognition is on a systematic basis over the periods in which the Company recognizes costs for which the credits are intended to compensate (i.e., qualified expenses).

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The Company benefits in the United Kingdom from His Majesty’s Revenue & Customs (“HMRC”) R&D Expenditure Credit (“RDEC”), which provides relief against U.K. corporation tax. Based on criteria established by HMRC, a portion of the Company’s expenditures incurred on R&D activities are eligible for RDEC relief. The Company recognizes the benefit as a reduction of the related R&D expenses on the Consolidated Statements of Operations and Comprehensive Loss.

Leases

The Company assesses whether contracts represent or contain leases at inception by determining whether the Company has the right to use, or control the use of, an identified asset from which it can obtain substantially all the economic benefits for a defined period.

The Company leases its corporate headquarters in the United Kingdom, where its facilities contain R&D, laboratory and office space of approximately 123,000 square feet. In addition, the Company leases approximately 45,000 square feet of office space in the United States, and small offices in Ireland and Switzerland. The leases in the United Kingdom expire between 2037 and 2043. Estimates of the term consider non-cancellable periods and include options to extend or terminate the lease when it is reasonably certain that the Company will exercise such options.

Operating lease right-of-use assets and liabilities are recognized at the lease commencement date. Right-of-use assets are initially measured at cost, representing the initial amount of the lease liability and any initial direct costs incurred, with a reduction for any lease incentives received. Lease liabilities are initially measured at the present value of the lease payments.

Since the rate implicit in leases is not readily determinable, the Company uses available information to determine its incremental borrowing rates, which represent the rate of interest that the Company would have to pay to borrow on a collateralized basis over a similar term for an amount equal to the lease payments in a similar economic environment.

Fixed lease components include rental payments at inception and termination costs for leases not reasonably certain of extension. Such components are accounted for as part of the right-of-use assets and lease liabilities and recognized on a straight-line basis over the lease term. Variable lease components include subsequent indexation-related rental increases. If such variable components do not coincide with a remeasurement of the lease term, the additional costs are recorded as a variable component of the lease expense in the Consolidated Statements of Operations and Comprehensive Loss as incurred. Non-lease components such as maintenance costs and service charges are separated from lease components and recognized separately in the Consolidated Statements of Operations and Comprehensive Loss.

Operating lease costs are allocated to R&D and Selling, general and administrative ("SG&A") expenses in the Consolidated Statements of Operations and Comprehensive Loss. The related lease cash flows are categorized under Net cash used in operating activities in the Consolidated Statements of Cash Flows. The Company elects not to recognize right-of-use assets and lease liabilities for short-term leases with a term of 12 months or less containing no repurchase options reasonably certain of exercise, and the expense for these short-term leases is immaterial. The Company does not have financing leases.

Property and equipment

Property and equipment are stated at cost net of accumulated depreciation and impairment losses. The Company expenses repairs and maintenance related to property and equipment in the Consolidated Statements of Operations and Comprehensive Loss when the costs are incurred.

Depreciation is charged to the Consolidated Statements of Operations and Comprehensive Loss on a straight-line basis over the estimated useful lives of assets as follows:

•Laboratory equipment -3 to 7 years

•Office equipment and other assets -3 to 5 years

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Impairment of long-lived assets

The Company assesses whether circumstances indicate that the estimated remaining useful life of its long-lived assets should be changed or that the carrying value of such assets may be impaired. The Company did not identify any such circumstances or recognize any impairment charges for the years ended December 31, 2025, 2024 and 2023.

Cash and cash equivalents

Cash and cash equivalents comprise cash balances and short-term money market funds with an original maturity of less than three months. Money market funds are presented at fair value in the Consolidated Balance Sheets.

Marketable securities

Marketable securities consist of investment funds which are measured and reported at fair value determined using quoted market prices. The investment funds are primarily invested in U.S. investment-grade debt securities, including asset-backed and mortgage-backed securities. Marketable securities are available to the Company for use in current operations and are classified as current assets. Gains and losses from marketable securities are recognized in Other income (expense), net.

Concentrations of credit risk and off-balance sheet risk

Financial instruments that potentially subject the Company to concentrations of credit risk are accounts receivable, cash equivalents, marketable securities and deposits held with banks and financial institutions. Cash, cash equivalents, marketable securities and deposits are maintained with high-quality financial institutions in Europe and the United States. The Company has not experienced any credit losses with such institutions and has incurred an immaterial amount of losses in relation to its accounts receivable from customers. The Company has no financial instruments with off-balance sheet risk of loss. As of December 31, 2025 and 2024, the amounts of expected credit losses recognized in the Consolidated Balance Sheets were not material.

Interest-bearing loans and borrowings

The Company issued 2.5% Convertible Senior Notes due in 2030 in February 2024 (the "Notes"), and evaluated to determine whether they contain features that qualify as embedded derivatives in accordance with ASC 815. Embedded derivatives must be separately measured from the host contract if all the requirements for bifurcation are met. The assessment of the conditions surrounding the bifurcation of embedded derivatives depends on the nature of the host contract and the features of the derivatives. In accounting for the issuance of the Notes, the Company treats the instrument wholly as a liability, in accordance with ASC 470, as the conversion features do not require bifurcation as a derivative in accordance with ASC 815 and the Notes were not issued at a substantial premium.

The Company offsets issuance costs against the initial value of the debt on the Company’s Consolidated Balance Sheets and amortizes the costs over the loan term using the effective interest method. Such costs are recognized under Interest expense in the Consolidated Statements of Operations and Comprehensive Loss.

Fair value measurements

Where financial and non-financial assets and liabilities are measured at fair value, the Company uses appropriate valuation techniques for which sufficient data are available, maximizing the use of relevant observable inputs and minimizing the use of unobservable inputs.

Fair values are categorized into different levels in a fair value hierarchy based on the inputs used in the valuation techniques as follows:

•Level 1: quoted prices (unadjusted) in active markets for identical assets or liabilities.

•Level 2: inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly (i.e., as prices) or indirectly (i.e., derived from prices).

•Level 3: inputs for the asset or liability that are not based on observable market data (unobservable inputs), and that are significant to the fair value of the assets or liabilities.

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As of December 31, 2025 and 2024, the Company held $366.8 million and $338.1 million, respectively, of money market funds required to be measured at fair value on a recurring basis within cash and cash equivalents. In addition, as of December 31, 2025 and 2024, the Company held $396.4 million and $364.6 million, of marketable securities, respectively, including unrealized gains of $19.7 million and $14.6 million, respectively. The fair value of these cash equivalents and marketable securities is based on quoted prices from active markets (Level 1 inputs). The Company recognizes transfers between levels of the fair value hierarchy at the end of the reporting period during which the changes have occurred. There were no transfers between levels of fair value hierarchy in the years ended December 31, 2025 and 2024. Other financial instruments, although not recorded at fair value on a recurring basis, include cash, accounts receivable, accounts payable and interest-bearing loans and borrowings.

On November 8, 2024, the Company, repaid in full the loan outstanding under the Pharmakon Loan Agreement. The fair value of borrowings under the Notes and Pharmakon Loan Agreement (disclosed in Note 7. “Non-current interest-bearing loans and borrowings”) were based on Level 2 inputs, which include observable inputs estimated using discounted cash flows and market-based expectations for interest rates, credit risk, and the contractual terms of debt instruments. After initial recognition, borrowings are measured at amortized cost using the effective interest method.

Net loss per share

Basic and diluted net loss per share is calculated by dividing the net loss for the period by the weighted average number of ordinary shares outstanding during the period. The dilutive effect of potential ordinary shares through share options, RSUs and the Notes are considered to be anti-dilutive as they would decrease the net loss per share and are therefore excluded from the calculation of diluted net loss per share.

Recently issued and recently adopted accounting pronouncements

In December 2023, the FASB issued ASU 2023-09, Improvements to Income Tax Disclosures. This ASU improves the transparency of income tax disclosure by requiring consistent categories and greater disaggregation of information in the rate reconciliation, and income taxes paid disaggregated by jurisdiction. This guidance is effective for the Company for the year beginning January 1, 2025. The Company adopted this ASU for the annual period ended December 31, 2025 and the amendments have been applied retrospectively to all prior periods presented in the financial statements by expanding the Company's income tax disclosure in Note 12. "Income Taxes."

In November 2024, the FASB issued ASU 2024-03, Income Statement – Reporting Comprehensive Income – Expense Disaggregation Disclosures (Subtopic 220-40). This ASU requires disclosure in the notes to the financial statements, at each interim and annual reporting period, of specified information about certain costs and expenses including purchases of inventory, employee compensation, depreciation and intangible asset amortization included in each relevant expense caption. Also required is a qualitative description of the amounts remaining in relevant expense captions that are not separately disaggregated. This ASU is effective for all public entities for annual reporting periods beginning after December 15, 2026, and interim periods within annual reporting periods beginning after December 15, 2027, and early adoption is permitted. This ASU should be applied either prospectively to financial statements issued after the effective date of this update or retrospectively to all prior periods presented in the financial statements. The Company is currently evaluating these new disclosure requirements and the impact of adoption on its financial statements.

3. Revenue

Collaboration revenue

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Revenue from sale of therapies, net

During the year ended December 31, 2025, the Company recognized $400.0 million (2024: $310.0 million, 2023: $238.7 million) of net revenue from sale of therapies, relating to the sale of KIMMTRAK, primarily in the United States and Europe, after estimated deductions for rebates, chargebacks and returns, which are recognized in Accrued expenses and other current liabilities, as set out in the Company’s accounting policies.

The Company recognized revenues from four customers accounting for 23%, 23%, 17% and 18% of the Company’s revenue from sale of therapies, net for the year ended December 31, 2025, four customers accounting for 29%, 27%, 18%, and 17% of the Company’s revenue from sale of therapies, net for the year ended December 31, 2024, and four customers accounting for 29%, 26%, 17%, and 16% and of the Company’s revenue from sale of therapies, net for the year ended December 31, 2023.

Revenue from sale of therapies, net is presented by country / region based on the location of the end customer below (in thousands):

Revenue from sale of therapies, net for the year ended December 31, 2025 includes $25.9 million (2024: $13.7 million, 2023: $3.6 million), of partnered revenue pursuant to the Company's separate agreements with Medison Pharma Ltd, ("Medison"), and Er-Kim Pharmaceuticals Bulgaria EOOD ("Er-Kim"). Revenue from these agreements is allocated between the Company's European and international markets.

Accounts receivable from contracts with customers

Accounts receivable as of December 31, 2025 and 2024 were as follows (in thousands):

As of December 31, 2025, four customers individually accounted for approximately 20%, 18%, 20% and 16% of accounts receivable associated with the Company’s net revenue from sale of therapies, as compared to 22%, 22%, 20% and 15% as of December 31, 2024. An allowance for lifetime expected credit losses on accounts receivable is measured using historical credit loss experience, conditions at the end of each reporting period, and reasonable and supportable forecasts that affect collectability. Expected credit losses as of December 31, 2025 and 2024 were immaterial.

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Accruals for rebates and chargebacks

Current and non-current accruals for rebates, chargebacks and returns as of December 31, 2025 and 2024 were as follows (in thousands):

Rebates Chargebacks Returns Total

Adjustments related to prior period sales 18,104 — — 18,104

Adjustments related to prior period sales (5,983) — — (5,983)

The adjustments related to prior period sales in the year ended December 31, 2025 were due to changes in estimates primarily related to European pricing negotiations.

Deferred revenue

For the year ended December 31, 2025, there was $0.4 million revenue recognized that was included in Deferred revenue as of January 1, 2025 (2024: $0; 2023: $7.8 million).

Deferred revenue in the Consolidated Balance Sheets is primarily in respect of the upfront fee and development milestone consideration received from collaboration agreements in advance of services performed by the Company.

Non-current deferred revenue in the Consolidated Balance Sheets as of December 31, 2025, relates to a revised distribution agreement with Medison entered into in November 2022. Under the revised agreement, the Company received a non-refundable payment of $5.0 million in exchange for granting Medison exclusive distribution rights in South America. The Company has determined that the deferred revenue relates to the Company’s single, combined performance obligation to supply KIMMTRAK to Medison and to grant Medison the exclusive right to distribute KIMMTRAK in South America. The revenue will be recognized on a straight-line basis over the term of the contract of 10 years from the date of the first commercial sale in the territory. Following the first commercial sale in the territory during the three months ended June 30, 2025, the Company began recognizing this revenue within net revenue from sale of therapies and consequently the Company reclassified the portion of deferred revenue expected to be recognized over the next twelve months as current.

Genentech Collaboration

Under the Genentech agreement signed in November 2018, the Company received aggregate non-refundable payments totaling $100 million consisting of an initial upfront payment of $50 million and $50 million paid upon an investigational new drug filing for the first clinical trial of the product candidate compound, in exchange for granting Genentech rights to co- develop/co-promote the Company’s IMC-C103C program and the co-exclusive worldwide license to the Company’s intellectual property rights in MAGE A4 soluble TCR bispecific therapeutic candidate compounds. The Company was responsible for development of the IMC-C103C program over the period of time to estimated completion of the Phase 1 clinical trial, with costs being shared equally with Genentech.

In February 2023, as the Company elected to withdraw from co-funding with Genentech the MAGE-A4 HLA-A02 program, IMC-C103C, Genentech acquired an exclusive worldwide license to the MAGE-A4 HLA-A02 soluble TCR bispecific therapeutic candidate compounds and shall be fully responsible for all further development and commercialization of such candidate compounds, at its expense.

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The transaction price was recorded as deferred revenue on receipt in November 2018 and allocated to a single combined performance obligation covering the granting of the co-exclusive worldwide license, the provision of development services and participation on a joint steering committee. This deferred revenue is recognized as the Company satisfies the combined performance obligation over the estimated period of time to when the Company has completed substantially all of its responsibilities associated with its withdrawal from the co-funding and the Phase 1 clinical trial. R&D costs reimbursed under the 2018 Genentech Agreement are considered variable consideration and not recognized in the transaction price until it is probable that the recognition of such revenue will not be reversed.

During the year ended December 31, 2025, the Company recognized no revenue relating to the 2018 Genentech Agreement (2024: $0.2 million; 2023: $10.7 million). The revenue recognized represents both deductions from deferred revenue and R&D costs reimbursed, predominantly for clinical trial costs. Such reimbursements arise in order to ensure that R&D costs are shared equally in accordance with the 2018 Genentech agreement. As of December 31, 2023, the Company determined its performance obligation under its collaboration with Genentech was complete. If MAGE-A4 HLA-A02 targeted products are commercialized, the Company would be eligible to receive development and commercial milestone payments plus royalties from Genentech on any sales of MAGE-A4 HLA-A02 targeted products arising under the Genentech Agreement. The Company determined achieving commercialization milestones and royalties to be unlikely and were excluded from the transaction price as of December 31, 2025, 2024 and 2023; therefore, any future milestones will be recorded when they become probable of being achieved.

Bristol-Myers Squibb ("BMS") Collaboration

In February 2024, we entered into a clinical trial collaboration and supply agreement with BMS (the "BMS Agreement") to investigate our ImmTAC bispecific TCR candidate targeting PRAME HLA-A*02:01, brenetafusp, in combination with BMS’s nivolumab, in first-line advanced cutaneous melanoma. Under the terms of the BMS Agreement, we are sponsoring and funding the registrational Phase 3 clinical trial of brenetafusp in combination with nivolumab in first-line advanced cutaneous melanoma (PRISM-MEL-301), and BMS is providing nivolumab. No monetary consideration is transferred as a result of the BMS Agreement.

4. Prepaid expenses and other current assets

Prepaid expenses and other current assets consist of the following (in thousands):

Included within other current assets are amounts paid in advance to clinical research organizations that are expected to be received through services rendered or repaid within 12 months.

5. Property and equipment, net

Property and equipment, net, consisted of the following (in thousands):

Office equipment and other assets 3,857 3,534

Total property and equipment, net $ 11,462 $ 10,092

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Depreciation expense for the years ended December 2025, 2024 and 2023 was $3.1 million, $4.2 million and $4.1 million, respectively.

6. Accrued expenses and other current liabilities

Accrued expenses and other current liabilities consisted of the following (in thousands):

See Note 3. “Revenue” for a breakdown of rebates, chargebacks and returns.

Clinical accruals primarily represent unbilled work undertaken by CROs as part of the advancement of the Company's clinical programs.

7. Interest-bearing loans and borrowings

Non-current interest-bearing loans and borrowings consisted of the following as of December 31, 2025 (in thousands):

Fair Value

Pharmakon loan — — — Not applicable

Non-current interest-bearing loans and borrowings consisted of the following as of December 31, 2024 (in thousands):

Fair Value

Pharmakon loan — — — Not applicable

Interest expense consisted of the following (in thousands):

Convertible senior notes

Amortization of debt issuance costs $ 2,104 $ 1,875

Pharmakon loan $ — $ 7,659

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Convertible senior notes

On February 2, 2024, the Company completed a private offering (the "Offering") of $402.5 million aggregate principal amount of Notes, including the exercise in full of the initial purchasers’ option to purchase up to an additional $52.5 million principal amount of Notes. The Notes were issued pursuant to an indenture, dated February 2, 2024, as supplemented on March 17, 2025 (the "Indenture"), between the Company and U.S. Bank Trust Company, National Association, as trustee. The Company’s net proceeds from the Offering of the Notes were $389.1 million, after deducting issuance costs of $13.4 million.

The Notes are senior, unsecured obligations of the Company and will mature on February 1, 2030, unless earlier converted, redeemed or repurchased. The Notes will accrue interest payable semi-annually in arrears on February 1 and August 1 of each year, beginning on August 1, 2024, at a rate of 2.50% per year.

Issuance costs incurred with the Notes were $13.4 million and are being amortized as interest expense on an effective interest rate method over the expected life of the Notes, through February 2030, at an effective interest rate of 3.06%.

Holders may convert all or any portion of their Notes at their option at any time prior to the close of business on the business day immediately preceding the maturity date into American Depositary Shares ("ADSs") of the Company. The Notes have an initial conversion rate of 10.5601 ADSs per $1,000 principal amount of the Notes, which will be subject to anti-dilution adjustments in certain circumstances. This represented an initial conversion price of $94.70 per ADS. The number of shares that would be issuable assuming conversion of all of the Notes is 5,950,600 (assuming the maximum increase to the conversion rate in connection with a “make-whole fundamental change” (as defined in the Indenture)). Following certain corporate events that occur prior to the maturity date of the Notes or if the Company delivers a notice of optional redemption or a notice of tax redemption, the Company shall, in certain circumstances, increase the conversion rate for a holder of the Notes who elects to convert its notes in connection with such a corporate event or convert its notes called (or deemed called) for redemption in connection with such notice of optional redemption or notice of tax redemption, as the case may be.

The Company may not redeem the Notes prior to February 5, 2027, except in the event of certain tax law changes as described below and in the Indenture. The Company may redeem for cash all or any portion of the Notes (subject to the partial redemption limitation described in the Indenture), at its option, on or after February 5, 2027 if the last reported sale price of the ADSs has been at least 130% of the conversion price for the Notes then in effect for at least 20 trading days (whether or not consecutive) during any 30 consecutive trading day period (including the last trading day of such period) ending on, and including, the trading day immediately preceding the date on which the Company provides notice of optional redemption, at a redemption price equal to 100% of the principal amount of the Notes to be redeemed, plus accrued and unpaid interest to, but excluding, the optional redemption date.

If, as a result of certain changes in the law of any relevant tax jurisdiction, the Company would be required to pay additional amounts (as defined in the Indenture) on the Notes, the Company may redeem the Notes in whole, but not in part, at a tax redemption price of 100% of the aggregate principal amount thereof, plus accrued and unpaid interest to, but excluding, the tax redemption date and all additional amounts, if any, which otherwise would be payable to the date of tax redemption. Upon the Company giving notice of a tax redemption, a holder may elect not to have its Notes redeemed, in which case the holder would not be entitled to receive any additional amounts with respect to its Notes after the tax redemption date.

If the Company undergoes a fundamental change, holders may require the Company to repurchase for cash all or any portion of their Notes at a repurchase price equal to 100% of the principal amount of the Notes to be repurchased, plus accrued and unpaid interest to, but excluding, the fundamental change repurchase date.

Pharmakon loan

On November 8, 2022, the Company entered into the Pharmakon loan agreement (the "Pharmakon Loan Agreement"), providing for term loans to the Company in an aggregate principal amount of up to $100 million to be funded in two tranches. The first tranche of $50 million bore interest at a fixed rate of 9.75%, which was payable quarterly in arrears, with payments commencing in 2023. The Company was also required to pay a further fee of $1.25 million at the latest by June 2024, regardless of whether it elected to draw down on the second $50 million tranche under the Pharmakon Loan Agreement. The Company elected not to exercise the option to draw down the second tranche and made the payment of $1.25 million in June 2024.

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