Financial Analysis

16. Commitments and Contingencies License Agreements The Company has entered into license agreements with various parties under which it is obligated to make contingent and non-contingent payments (see Note 13). Manufacturing Commitments The Company entered into supply agreements with Regeneron to provide both clinical supply and commercial product (see Note 13). In May 2023, the Company signed a letter of intent with Samsung related to its technology transfer of the manufacturing process for ARCALYST drug substance. The Company has additionally entered into agreements with several CDMOs to provide the Company with preclinical and clinical trial materials for its non-ARCALYST assets. As of December 31, 2025, the Company had committed to minimum payments under these agreements totaling $175,704, of which $46,924 are due within one year. The Company issued termination notices to CDMOs in February 2025 to terminate the clinical supply agreements for the production of abiprubart. During the year ended December 31, 2025, the Company recorded and paid $ 2,500 in research and development expenses because of these terminations. The Company does not expect to incur any additional expenses because of these terminations. Performance Cash Awards Beginning in the second quarter of 2025, the Company began granting cash awards (Performance Cash Awards) to certain eligible employees pursuant to the 2018 Plan, which were eligible to be received upon the achievement of certain specified develo …

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18. Benefit Plans The Company has established a defined-contribution savings plan under Section 401(k) of the Internal Revenue Code. This plan covers substantially all Kiniksa US employees who meet minimum age and service requirements and allows participants to defer a portion of their annual compensation on a pre-tax basis. The Company provides matching contributions of 100% of the first 3% of each participants salary contributed, plus 50% for each of the next 2% contributed. Employees are immediately and fully vested in their own contributions and the Companys match. During the years ended December 31, 2025, 2024 and 2023, the Company contributed $3,544, $2,923 and $2,305 respectively, to the plan. …

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Years Ended December 31, 2025 2024 2023 Product Revenue, net $ 677,564 $ 417,029 $ 233,176 …

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11. Share-Based Compensation As part of the Redomiciliation, Kiniksa International assumed the sponsorship of, and all rights and obligations of Kiniksa Bermuda under Kiniksa Bermudas equity compensation plans, which include the 2018 Plan, the 2015 Plan, and the 2018 ESPP. 2018 Incentive Award Plan In May 2018, the Companys board of directors and shareholders approved the 2018 Incentive Award Plan (the 2018 Plan), which became effective on May 23, 2018. The 2018 Plan provides for the grant of incentive share options, nonqualified share options, share appreciation rights, restricted shares, dividend equivalents, restricted share units and other share- or cash- based awards. Upon the effectiveness of the 2018 Plan, the Company ceased granting awards under its 2015 Equity Incentive Plan (as amended, the 2015 Plan together with the 2018 Plan, the Plans). A total of 4,466,500 Class A ordinary shares were initially reserved for issuance under the 2018 Plan. The number of Class A ordinary shares that may be issued under the 2018 Plan will automatically increase on each January 1, beginning in 2019 and continuing for each fiscal year until, and including, the fiscal year ending December 31, 2028, equal to the lesser of (1) 4% of the Class A ordinary shares outstanding (on an as-converted basis) on the final day of the immediately preceding calendar year and (2) a smaller number of Class A ordinary shares determined by the Companys board of directors. As of December 31, 2025, 5,621,35 …

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3. Fair Value of Financial Assets and Liabilities The following tables present information about the Companys financial instruments measured at fair value on a recurring basis and indicate the level of the fair value hierarchy used to determine such fair values: Fair Value Measurements as of December 31, 2025 Using: Level 1 Level 2 Level 3 Total Assets: Cash equivalents money market funds $ 77,291 $ $ $ 77,291 Short-term investments U.S. Treasury Securities 248,478 248,478 Total $ 77,291 $ 248,478 $ $ 325,769 Fair Value Measurements as of December 31, 2024 Using: Level 1 Level 2 Level 3 Total Assets: Cash equivalents money market funds $ 135,275 $ $ $ 135,275 Short-term investments U.S. Treasury Securities 60,046 60,046 Total $ 135,275 $ 60,046 $ $ 195,321 During the years ended December 31, 2025 and 2024 there were no transfers between Level 1, Level 2 and Level 3. The money market funds were valued using quoted prices in active markets, which represent a Level 1 measurement in the fair value hierarchy. The Companys cash equivalents and short-term investments as of December 31, 2025 and 2024 included United States Treasury securities, which are not traded on a daily basis and, therefore, represent a Level 2 measurement in the fair value hierarchy at each period end. The contractual maturities of short-term investments were as follows: December 31, December 31, 2025 2024 Maturities within one year $ 179,577 $ 60,046 Maturities after one year through five years 68,901 Total $ …

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"14. Income Taxes Prior to the Redomiciliation, the Company was incorporated and principally subject to taxation in Bermuda. Following the Redomiciliation, the Company is incorporated and principally subject to taxation in the United Kingdom. Under the previous laws of Bermuda, tax on a companys income is assessed at a zero percent tax rate. As a result, the Company has not recorded any income tax benefits from its losses incurred in Bermuda during the reporting periods in which it was incorporated there, and no net operating loss carryforwards will be available to the Company for those losses. Following the Redomiciliation, the Companys income is subject to the enacted United Kingdom statutory corporate tax rate and net operating losses incurred have an indefinite carryforward. The Companys wholly owned United States subsidiaries, Kiniksa US and Primatope, are subject to federal and state income taxes in the United States. The Companys wholly owned subsidiary Kiniksa Bermuda remained subject to taxation, if any, in Bermuda for the period of time prior to its liquidation in November 2025. The Companys wholly owned subsidiary Kiniksa UK, and Kiniksa UKs wholly owned subsidiaries, Kiniksa Switzerland, Kiniksa Germany, and Kiniksa France are subject to taxation in their respective countries. Certain of the Companys subsidiaries operate under cost plus intercompany arrangements. The Company has engaged in a series of intra-entity asset transfers and allocations to contribute asse …

IncomeTaxDisclosureTextBlock · excerpt; the full note is in the filing

7. Leases The Company leases office, laboratory space and vehicles under operating leases. In May 2023, the Company entered into a lease amendment to extend the term of the Lexington, Massachusetts headquarters lease by forty-eight months to August 31, 2028. The Company accounted for the lease amendment as a modification and recorded increases in the right-of-use-assets and lease liability of $8,515. The components of lease cost for the year ended December 31, 2025, 2024 and 2023 are as follows: Years Ended December 31, 2025 2024 2023 Operating lease cost $ 4,377 $ 3,875 $ 3,749 Variable lease cost 894 708 1,023 Short-term lease cost 15 153 - Total lease cost $ 5,286 $ 4,736 $ 4,772 Variable lease costs primarily related to operating expense, taxes and insurance associated with the Companys operating leases. As these costs are generally variable in nature, they are not included in the measurement of the operating lease asset and related lease liability. December 31, 2025 Weighted-average remaining lease term (years) 2.66 Weighted-average discount rate 6.98% Maturities of operating leases liabilities were as follows: As of December 31, 2026 $ 3,480 2027 4,164 2028 2,563 2029 193 2030 80 Thereafter Total future minimum lease payments $ 10,480 Less imputed interest (983) Present value of lease liabilities $ 9,497 …

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Recently Issued Accounting Pronouncements In November 2024, the FASB issued Accounting Standards Update (ASU) 2024-03, Income Statement-Reporting Comprehensive Income-Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses , requiring public entities to disclose additional information about specific expense categories in the notes to the financial statements on an interim and annual basis. ASU 2024-03 is effective for fiscal years beginning after December 15, 2026, and for interim periods beginning after December 15, 2027, with early adoption permitted. The Company is currently evaluating the impact of adopting ASU 2024-03 on its consolidated financial statements. In September 2025, the FASB issued ASU 2025-06, IntangiblesGoodwill and OtherInternal-Use Software (Subtopic 350-40): Targeted Improvements to the Accounting for Internal-Use Software . ASU 2025-06 modernizes and simplifies the accounting for software development costs by establishing a single capitalization framework for all internally developed or acquired software, regardless of whether the software is intended for internal use, to be sold, or to be used in delivering products and services. The new guidance retains the concept of project stages but eliminates the historical distinction between internal-use software and software to be sold or marketed. ASU 2025-06 is effective for fiscal years beginning after December 15, 2027, including interim periods within those fiscal …

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4. Product Revenue, Net ARCALYST The Company derives substantially all of its product revenue, net from sales of ARCALYST in the United States, which was as follows: Years Ended December 31, 2025 2024 2023 Product Revenue, net $ 677,564 $ 417,029 $ 233,176 The following tables summarizes balances and activity in each of the product revenue allowance and reserve categories for the years ended December 31, 2025 and 2024: Contractual Government Adjustments Rebates Returns Total Balance at December 31, 2024 $ 3,495 $ 8,640 $ 2,294 $ 14,429 Current provisions relating to sales in the current year 36,209 26,882 1,704 64,795 Adjustments relating to prior years (2,306) (718) (3,024) Payments/returns relating to sales in the current year (31,650) (15,995) (47,645) Payments/returns relating to sales in the prior years (3,495) (5,338) (156) (8,989) Balance at December 31, 2025 $ 4,559 $ 11,883 $ 3,124 $ 19,566 Contractual Government Adjustments Rebates Returns Total Balance at December 31, 2023 $ 2,022 $ 3,775 $ 341 $ 6,138 Current provisions relating to sales in the current year 24,738 18,436 1,296 44,470 Adjustments relating to prior years (31) (155) 836 650 Payments/returns relating to sales in the current year (21,277) (9,796) (31,073) Payments/returns relating to sales in the prior years (1,957) (3,620) (179) (5,756) Balance at December 31, 2024 $ 3,495 $ 8,640 $ 2,294 $ 14,429 Total revenue-related reserves as of December 31, 2025 and 2024, included in the Companys consolidated ba …

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17. Segment Information and Geographic Data The Company manages its operations as a single operating segment for the purposes of assessing performance and making operating decisions. The Companys singular focus is on developing and commercializing novel therapies that target cardiovascular diseases with significant unmet medical need. The Companys Chief Operating Decision Maker (CODM) is the Chief Executive Officer. The Companys CODM reviews consolidated operating results and decides how to allocate resources based on net income that also is reported on the income statement as consolidated net income. The measure of segment assets is reported on the balance sheet as total consolidated assets. The CODM utilizes net income to make key decisions about how to allocate resources across the Companys commercial product and development programs. The following table presents selected financial information with respect to the Companys single operating segment for the years ended December 31, 2025, 2024 and 2023: Years Ended December 31, 2025 2024 2023 Revenue: Product revenue, net $ 677,564 $ 417,029 $ 233,176 License and collaboration revenue - 6,210 37,083 Total revenue 677,564 423,239 270,259 Operating expenses: Cost of goods sold 77,673 60,910 33,407 Collaboration expenses 229,545 128,311 56,524 Direct research and development expenses by program: ARCALYST 1,040 1,080 2,628 KPL-387 47,265 11,221 2,537 KPL-1161 4,198 581 - Abiprubart 6,122 59,459 28,388 Vixarelimab 44 1,530 7,717 Un …

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2. Summary of Significant Accounting Policies Cash and Cash Equivalents The Company classifies deposits in banks, money market funds and cash invested temporarily in various instruments with maturities of three months or less at the time of purchase as cash and cash equivalents. As of December 31, 2025 and 2024 cash and cash equivalents consisted principally of amounts held in money market accounts and cash on deposit at commercial banks. Short-Term Investments The Company generally invests its excess cash in money market funds and short-term investments in U.S. Treasury securities. The Company has classified its investments with maturities beyond one year as short-term, based on their highly liquid nature and because such marketable securities represent the investment of cash that is available for current operations. Such investments which are included in short-term investments on the Companys consolidated balance sheets are considered available-for-sale (AFS) debt securities and are reported at fair value with unrealized gains and losses recognized in accumulated other comprehensive income (loss) in shareholders equity, net of related tax effects. Realized gains and losses, if any, on short-term investments are included in interest income. If the AFS debt securitys fair value declines below its amortized cost the Company considers all available evidence to evaluate the extent to which the decline is due to credit-related factors or noncredit-related factors. If the decline …

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10. Ordinary Shares The rights of the holders of the Companys Class A ordinary shares, Class B ordinary shares, Class A1 ordinary shares and Class B1 ordinary shares are identical, except with respect to voting, transferability and conversion, as described below. The Company has authorized 200,000,000 shares, at a nominal value of $0.000273235 as of December 31, 2025 and 2024. Voting Each Class A ordinary share entitles the holder to one vote on all matters submitted to the shareholders for a vote. Each Class B ordinary share entitles the holder to ten votes on all matters submitted to the shareholders for a vote. The holders of Class A and Class B ordinary shares, voting together as a single class, are entitled to elect the directors of the Company. Holders of Class A1 ordinary shares and Class B1 ordinary shares have no voting rights. Dividends The Companys ordinary shareholders are entitled to receive dividends, as may be declared by the Companys board of directors. Through December 31, 2025, no cash dividends have been declared or paid. Conversion Each Class B ordinary share automatically converts into one Class A ordinary share upon certain transfers of such shares by the holder thereof (subject to certain exceptions). Each Class B ordinary share is convertible, at the holders election into one Class A ordinary share or one Class B1 ordinary share. Each Class A1 ordinary share is convertible into one Class A ordinary share at the holders election (subject to certain exce …

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13. Commitments and Contingencies License Agreements The Company has entered into license agreements with various parties under which it is obligated to make contingent and non-contingent payments (see Note 10). Manufacturing Commitments The Company has a supply agreement with Regeneron pursuant to which the Company may order both clinical and commercial product (see Note 10). In June 2024, the Company entered into a Master Services Agreement and a Product Specific Agreement with Samsung Biologics Co., Ltd. as part of its technology transfer of the manufacturing process for ARCALYST drug substance. The Company has additionally entered into agreements with several contract development and manufacturing organizations to provide the Company with preclinical and clinical trial materials for its non-ARCALYST assets. As of June 30, 2026, the Company had committed to minimum purchase commitments under all of these agreements totaling $205,826, of which $118,532 is due within one year. The Company issued termination notices to contract development and manufacturing organizations in February 2025 to terminate the clinical supply agreements for the production of abiprubart. During the three months ended March 31, 2025, the Company recorded and paid $2,500 in research and development expenses because of these terminations. The Company does not expect to incur any additional expenses because of these terminations. Performance Cash Awards Beginning in the second quarter of 2025, the Compa …

CommitmentsAndContingenciesDisclosureTextBlock · excerpt; the full note is in the filing

Three Months Ended Six Months Ended June 30, June 30, 2026 2025 2026 2025 Product revenue, net $ 243,600 $ 156,797 $ 457,866 $ 294,582 …

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8. Share-Based Compensation The Company maintains several equity compensation plans, including the 2018 Incentive Award Plan (the 2018 Plan) and the 2018 Employee Share Purchase Plan (the 2018 ESPP). Upon the effectiveness of the 2018 Plan, the Company ceased granting awards under its 2015 Equity Incentive Plan (as amended, the 2015 Plan and together with the 2018 Plan, the Plans). 2015 Plan As of June 30, 2026, there were 77,296 Class A ordinary shares reserved for issuance pursuant to outstanding awards under the 2015 Plan that were granted prior to the effectiveness of the 2018 Plan. 2018 Plan The 2018 Plan provides for the grant of incentive share options, nonqualified share options, share appreciation rights, restricted shares, dividend equivalents, restricted share units (RSUs), PSUs (as defined below) and other share- or cash- based awards. Pursuant to the 2018 Plans evergreen provision, the number of shares available for future issuance under the 2018 Plan, as of January 1, 2026, increased by 3,051,742 Class A ordinary shares. As of June 30, 2026, 7,845,077 shares remained available for future grant under the 2018 Plan. 2018 ESPP In December 2025, the Companys board of directors approved an increase, as of January 1, 2026, of 110,000 Class A ordinary shares under the 2018 ESPP. As of June 30, 2026, 765,514 Class A ordinary shares were available for future issuance under the 2018 ESPP. Restricted Share Units The Company grants RSUs with service conditions to eligible e …

DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock · excerpt; the full note is in the filing

2. Fair Value of Financial Assets and Liabilities Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable: Level 1Quoted prices in active markets for identical assets or liabilities. Level 2Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data. Level 3Unobservable inputs that are supported by little or no market activity that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques. The following tables present information about the Companys financial instruments measured at fair value on a recurring basis and indicate the level of the fair value hierarchy used to determine such fair values: Fair Value Measurements as of June 30, 2026 Using: Level 1 Level 2 Level 3 Total Assets: Cash equivalents money market funds $ 71,484 $ $ $ 71,484 Cash equivalents U.S. Treasury Securities 1,688 1,688 Short-term investments U.S. Treasury Securities 350,251 350,251 $ 71,484 $ 351,939 $ $ 423,423 Fair Value Measurements as of December 31, 2025 Using: Level …

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12. Income Taxes The Companys income is subject to the enacted UK statutory corporate tax rate. The Companys wholly owned United States subsidiaries, including Kiniksa Pharmaceuticals Corp. (Kiniksa US), are subject to federal and state income taxes in the United States. The Companys wholly owned subsidiary Kiniksa Pharmaceuticals (UK), Ltd. (Kiniksa UK), and Kiniksa UKs wholly owned subsidiaries, including Kiniksa Pharmaceuticals, GmbH (Kiniksa Switzerland) and Kiniksa UKs Swiss branch office, are subject to taxation in their respective countries. Certain of the Companys subsidiaries operate under cost plus intercompany arrangements. The Company recorded an income tax provision of $5,713 and $15,802 for the three and six months ended June 30, 2026, respectively. The provision for income taxes was driven primarily by income earned in Switzerland, UK and United States as well as uncertain tax positions offset in part by tax benefits related to share-based compensation, and United States federal and state research and development credits (R&D Credits). The Company recorded an income tax provision of $5,045 and $12,071 for the three and six months ended June 30, 2025, respectively. The provision for income taxes was driven primarily by income earned in Switzerland, UK and United States as well as uncertain tax positions offset in part by tax benefits from Foreign Derived Intangible Income (FDII) deduction and United States federal and state R&D Credits. Management regula …

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Recently Issued Accounting Pronouncements In November 2024, the FASB issued Accounting Standards Update (ASU) 2024-03, Income Statement-Reporting Comprehensive Income-Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses , requiring public entities to disclose additional information about specific expense categories in the notes to the financial statements on an interim and annual basis. ASU 2024-03 is effective for fiscal years beginning after December 15, 2026, and for interim periods beginning after December 15, 2027, with early adoption permitted. The Company is currently evaluating the impact of adopting ASU 2024-03 on its consolidated financial statements. In September 2025, the FASB issued ASU 2025-06, IntangiblesGoodwill and OtherInternal-Use Software (Subtopic 350-40): Targeted Improvements to the Accounting for Internal-Use Software . ASU 2025-06 modernizes and simplifies the accounting for software development costs by establishing a single capitalization framework for all internally developed or acquired software, regardless of whether the software is intended for internal use, to be sold, or to be used in delivering products and services. The new guidance retains the concept of project stages but eliminates the historical distinction between internal-use software and software to be sold or marketed. ASU 2025-06 is effective for fiscal years beginning after December 15, 2027, including interim periods within those fiscal …

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3. Product Revenue, Net The Company derives substantially all of its product revenue, net from sales of ARCALYST in the United States, which was as follows: Three Months Ended Six Months Ended June 30, June 30, 2026 2025 2026 2025 Product revenue, net $ 243,600 $ 156,797 $ 457,866 $ 294,582 The following table summarizes balances and activity in each of the product revenue allowance and reserve categories for the six months ended June 30, 2026: Contractual Government Adjustments Rebates Returns Total Balance at December 31, 2025 $ 4,559 $ 11,883 $ 3,124 $ 19,566 Current provisions relating to sales in the current year 19,469 17,395 1,012 37,876 Adjustments relating to prior years (8) (1,463) (793) (2,264) Payments/returns relating to sales in the current year (18,228) (7,205) (25,433) Payments/returns relating to sales in the prior years (4,551) (7,522) (131) (12,204) Balance at June 30, 2026 $ 1,241 $ 13,088 $ 3,212 $ 17,541 Total revenue-related reserves as of June 30, 2026 and December 31, 2025, included in the Companys condensed consolidated balance sheets, are summarized as follows: June 30, December 31, 2026 2025 Components of accounts receivable $ (1,160) $ (831) Components of other current liabilities 18,701 20,397 Total revenue-related reserves $ 17,541 $ 19,566 Substantially all of the Companys trade accounts receivable arise from product revenue in the United States due from the Companys third party logistics provider. …

RevenueFromContractWithCustomerTextBlock · excerpt; the full note is in the filing

14. Segment Information and Geographic Data The Company manages its operations as a single operating segment for the purposes of assessing performance and making operating decisions. The Companys singular focus is on developing and commercializing novel therapies that target cardiovascular diseases with significant unmet medical need. The Companys Chief Operating Decision Maker (CODM) is the Chief Executive Officer. The Companys CODM reviews consolidated operating results and decides how to allocate resources based on net income that also is reported on the income statement as consolidated net income. The measure of segment assets is reported on the balance sheet as total consolidated assets. The CODM utilizes net income to make key decisions about how to allocate resources across the Companys commercial product and development programs. The following table presents selected financial information with respect to the Companys single operating segment for the three and six months ended June 30, 2026 and 2025: Three Months Ended Six Months Ended June 30, June 30, 2026 2025 2026 2025 Revenue: Product revenue, net $ 243,600 $ 156,797 $ 457,866 $ 294,582 License and collaboration revenue - - - - Total revenue 243,600 156,797 457,866 294,582 Operating expenses: Cost of goods sold 23,572 18,603 44,368 36,471 Collaboration expenses 88,069 52,418 163,646 96,208 Direct research and development expenses by program: ARCALYST 332 171 673 526 KPL-387 21,442 8,485 37,594 13,663 KPL-1161 766 …

SegmentReportingDisclosureTextBlock · excerpt; the full note is in the filing