# EDGAR Filing Document

**Accession Number:** 0001730430
**File Stem:** 0001104659-26-050359
**Filing Date:** 2026-4
**Character Count:** 138513
**Document Hash:** a8c3edb6d29282be79587323eae438f8
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001104659-26-050359.hdr.sgml**: 20260428

**ACCESSION NUMBER**: 0001104659-26-050359

**CONFORMED SUBMISSION TYPE**: 10-Q

**PUBLIC DOCUMENT COUNT**: 74

**CONFORMED PERIOD OF REPORT**: 20260331

**FILED AS OF DATE**: 20260428

**DATE AS OF CHANGE**: 20260428

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Kiniksa Pharmaceuticals International, plc
- **CENTRAL INDEX KEY:** 0001730430
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 981795578
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 10-Q
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-38492
- **FILM NUMBER:** 26908038

**BUSINESS ADDRESS:**
- **ADDRESS IS A NON US LOCATION:** YES
- **STREET 1:** 105 PICCADILLY, SECOND FLOOR
- **CITY:** LONDON
- **PROVINCE COUNTRY:** X0
- **ZIP:** W1J 7NJ
- **BUSINESS PHONE:** 7814319100

**MAIL ADDRESS:**
- **ADDRESS IS A NON US LOCATION:** YES
- **STREET 1:** 105 PICCADILLY, SECOND FLOOR
- **CITY:** LONDON
- **PROVINCE COUNTRY:** X0
- **ZIP:** W1J 7NJ

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** Kiniksa Pharmaceuticals, Ltd.
- **DATE OF NAME CHANGE:** 20180205

?xml version='1.0' encoding='ASCII'? Kiniksa Pharmaceuticals International, plc_March 31, 2026

[**Table of Contents**](#TOC)

------

**UNITED STATES**

**SECURITIES AND EXCHANGE COMMISSION**

**Washington, D.C. 20549**

**FORM 10-Q**

**(Mark One)**

**☒&nbsp;&nbsp;&nbsp;&nbsp; QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934**

**For the quarterly period ended March 31, 2026**

**OR**

**☐&nbsp;&nbsp;&nbsp;&nbsp; TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934**

**For the transition period from &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; to&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;** 

**Commission file number: 001-38492**

**Kiniksa Pharmaceuticals International, plc**

(Exact Name of Registrant as Specified in Its Charter)

---

| | |
|:---|:---|
| **England and Wales** | **98-1795578** |
| (State or Other Jurisdiction of | (I.R.S. Employer |
| Incorporation or Organization) | Identification No.) |

---

105 Piccadilly, Second Floor

London, W1J 7NJ

England, United Kingdom

(781) 431-9100

**(Address, zip code and telephone number, including area code of principal executive offices)**

Kiniksa Pharmaceuticals Corp.

100 Hayden Avenue

Lexington, MA, 02421

(781) 431-9100

**(Address, zip code and telephone number, including area code of agent for service)**

N/A

**(Former name, former address and former fiscal year, if changed since last report)**

N/A

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

---

| | | |
|:---|:---|:---|
| **Title of each class** | **Trading Symbol(s)** | **Name of each exchange on which registered** |
| Class A Ordinary Shares | KNSA | The Nasdaq Stock Market LLC <br>(Nasdaq Global Select Market) |

---

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes **☒** No **☐**

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes **☒** No **☐**

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of "large accelerated filer," "accelerated filer," "smaller reporting company" and "emerging growth company" in Rule 12b-2 of the Exchange Act.

---

| | | | |
|:---|:---|:---|:---|
| Large Accelerated Filer | ☒  | Accelerated Filer | ☐  |
| Non-accelerated Filer | ☐ | Smaller Reporting Company | ☐ |
|  |  | Emerging Growth Company  | ☐ |

---

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

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes **☐** No **☒**

As of April 24, 2026, there were 76,938,016 ordinary shares outstanding in aggregate, comprised of:

46,303,276 Class A ordinary shares, nominal value $0.000273235 per share

1,795,158 Class B ordinary shares, nominal value $0.000273235 per share

12,781,964 Class A1 ordinary shares, nominal value $0.000273235 per share

16,057,618 Class B1 ordinary shares, nominal value $0.000273235 per share

------

[**Table of Contents**](#TOC)

**Kiniksa Pharmaceuticals International, plc**

**FORM 10-Q**

**FOR THE THREE MONTHS ENDED MARCH 31, 2026**

**TABLE OF CONTENTS**

---

| | |
|:---|:---|
|  | **Page** |
| [**PART I — FINANCIAL INFORMATION**](#PartIFinancialInformation_402294) | 4 |
| [Item 1. Financial Statements (unaudited)](#Item1FinancialStatementsunaudited_945731) | 4 |
| &nbsp;&nbsp;&nbsp;[Condensed Consolidated Balance Sheets as of March 31, 2026 and December 31, 2025](#CONSOLIDATEDBALANCESHEETS_783498) | 4 |
| &nbsp;&nbsp;&nbsp;[Condensed Consolidated Statements of Operations and Comprehensive Income for the three months ended March 31, 2026 and 2025](#CONSOLIDATEDSTATEMENTOFOPERATIONS) | 5 |
| &nbsp;&nbsp;&nbsp;[Condensed Consolidated Statements of Shareholders' Equity for the three months ended March 31, 2026 and 2025](#CONSOLIDATEDSTATEMENTSOFCONVERTIBLEPREFE) | 6 |
| &nbsp;&nbsp;&nbsp;[Condensed Consolidated Statements of Cash Flows for the three months ended March 31, 2026 and 2025](#CONSOLIDATEDSTATEMENTSOFCASHFLOWS_539083) | 7 |
| &nbsp;&nbsp;&nbsp;[Notes to Condensed Consolidated Financial Statements](#NOTESTOCONSOLIDATEDFINANCIALSTATEMENTS_4) | 8 |
| [Item 2. Management's Discussion and Analysis of Financial Condition and Results of Operations](#Item2ManagementsDiscussionandAnalysisofF) | 23 |
| [Item 3. Quantitative and Qualitative Disclosures About Market Risk](#Item3QuantitativeandQualitativeDisclosur) | 31 |
| [Item 4. Controls and Procedures](#Item4ControlsandProcedures_73951) | 31 |
| [**PART II — OTHER INFORMATION**](#PARTIIOTHERINFORMATION_115360) | 33 |
| [Item 1. Legal Proceedings](#Item1LegalProceedings_791855) | 33 |
| [Item 1A. Risk Factors](#Risk_Factors) | 33 |
| [Item 2. Unregistered Sales of Equity Securities, Use of Proceeds and Issuer Purchases of Equity Securities](#Item2UnregisteredSalesofEquitySecurities) | 33 |
| [Item 3. Defaults Upon Senior Securities](#Item3DefaultsUponSeniorSecurities_443955) | 33 |
| [Item 4. Mine Safety Disclosures](#Item4MineSafetyDisclosures_69924) | 33 |
| [Item 5. Other Information](#Item5OtherInformation_655701) | 34 |
| [Item 6. Exhibits](#Item6Exhibits_424431) | 35 |
| [SIGNATURES](#SIGNATURES_66347) | 36 |

---

[**Table of Contents**](#TOC)

**SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS**

This Quarterly Report on Form 10-Q (this "Quarterly Report") contains forward-looking statements. All statements other than statements of historical facts contained in this Quarterly Report should be considered forward-looking statements, including statements regarding: our beliefs that KPL-387 will expand the recurrent pericarditis market and provide additional treatment options for patients; our beliefs about dosing and administration for our product candidates, including that KPL-387 has the potential for monthly subcutaneous self-administration in a liquid formulation and that KPL-1161 has the potential for quarterly subcutaneous dosing; our expectation to have data from the Phase 2 portion of our trial of KPL-387 in recurrent pericarditis in the second half of 2026 and that we plan to use the totality of the data to determine further development strategy; our plan to initiate a Phase 1 first-in-human clinical trial of KPL-1161 by the end of 2026; our expectation that our cash balance and our expected cash inflows from operations will allow us to meet our current operating plan and that our existing cash, cash equivalents and short-term investments will enable us to fund our operating expenses and capital expenditure requirements for at least the next 12 months; statements regarding our expected near-term expenditures and revenue; and other similar statements.

These statements involve known and unknown risks, uncertainties and other important factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements.

In some cases, you can identify forward-looking statements by terms such as "may," "will," "should," "expect," "plan," "anticipate," "could," "intend," "goal," "design," "target," "project," "contemplate," "believe," "estimate," "predict," "potential" or "continue" or the negative of these terms or other similar expressions, although not all forward-looking statements contain these identifying words. The forward-looking statements in this Quarterly Report are only predictions. We have based these forward-looking statements largely on our current expectations and projections about future events and financial trends that we believe may affect our business, financial condition and results of operations. These forward-looking statements speak only as of the date of this Quarterly Report and are subject to a number of risks, uncertainties and assumptions described in this Quarterly Report and Part I, Item 1A of our Annual Report on Form 10-K for the year ended December 31, 2025 (the "Annual Report"), as updated by any information appearing in Part II, Item 1A of any of our subsequent Quarterly Reports on Form 10-Q.

Because forward-looking statements are inherently subject to risks and uncertainties, some of which cannot be predicted or quantified and some of which are beyond our control, you should not place undue reliance on our forward-looking statements. Except as required by applicable law, we do not assume and specifically disclaim any obligation to update any forward-looking statements, whether as a result of any new information, future events, changed circumstances or otherwise.

**Industry and other data**

Unless otherwise indicated, certain industry data and market data included in this Quarterly Report were obtained from independent third party surveys, market research, publicly available information, reports of governmental agencies and industry publications and surveys. All of the market data used in this Quarterly Report involves a number of assumptions and limitations, and you are cautioned not to give undue weight to such estimates. We believe that the information from these industry publications and surveys included in this Quarterly Report is reliable.

ARCALYST is a registered trademark of Regeneron. Solely for convenience, trademarks, service marks, and trade names referred to in this Quarterly Report may be listed without identifying symbols.

[**Table of Contents**](#TOC)

**Part I — Financial Information**

**Item 1. Financial Statements (unaudited)**

#### KINIKSA PHARMACEUTICALS INTERNATIONAL, PLC

#### CONDENSED CONSOLIDATED BALANCE SHEETS
**(In thousands, except share and per share amounts)**

**(Unaudited)**

---

| | | |
|:---|:---|:---|
|  | **March 31,** <br>**2026** | **December 31,** <br>**2025** |
| **Assets** |  |  |
| Current assets: |  |  |
| &nbsp;&nbsp;&nbsp;&nbsp;Cash and cash equivalents | $189952 | $165596 |
| &nbsp;&nbsp;&nbsp;&nbsp;Short-term investments | 278141 | 248478 |
| &nbsp;&nbsp;&nbsp;&nbsp;Accounts receivable, net | 23224 | 15594 |
| &nbsp;&nbsp;&nbsp;&nbsp;Inventory | 73141 | 54895 |
| &nbsp;&nbsp;&nbsp;&nbsp;Prepaid expenses and other current assets | 29714 | 42614 |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Total current assets | 594172 | 527177 |
| Property and equipment, net | 1986 | 1943 |
| Operating lease right-of-use assets | 9334 | 9807 |
| Other long-term assets | 11162 | 11307 |
| Intangible asset, net | 15000 | 15250 |
| Deferred tax assets | 193626 | 198149 |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Total assets | $825280 | $763633 |
| **Liabilities and Shareholders' Equity** |  |  |
| Current liabilities: |  |  |
| &nbsp;&nbsp;&nbsp;&nbsp;Accounts payable | $24402 | $2028 |
| &nbsp;&nbsp;&nbsp;&nbsp;Accrued collaboration expenses | 75577 | 70015 |
| &nbsp;&nbsp;&nbsp;&nbsp;Accrued expenses | 32771 | 42020 |
| &nbsp;&nbsp;&nbsp;&nbsp;Operating lease liabilities | 3170 | 2987 |
| &nbsp;&nbsp;&nbsp;&nbsp;Other current liabilities | 20691 | 22134 |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Total current liabilities | 156611 | 139184 |
| Non-current liabilities: |  |  |
| &nbsp;&nbsp;&nbsp;&nbsp;Non-current deferred revenue | 31811 | 31811 |
| &nbsp;&nbsp;&nbsp;&nbsp;Non-current operating lease liabilities | 5855 | 6510 |
| &nbsp;&nbsp;&nbsp;&nbsp;Other long-term liabilities | 25316 | 18522 |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Total liabilities | 219593 | 196027 |
| Commitments and contingencies (Note 13) |  |  |
| Shareholders' equity: |  |  |
| &nbsp;&nbsp;&nbsp;&nbsp;Class A ordinary shares, nominal value of $0.000273235 per share; 46,054,720 shares and 45,659,424 shares issued and outstanding as of March 31, 2026 and December 31, 2025, respectively | 12 | 12 |
| &nbsp;&nbsp;&nbsp;&nbsp;Class B ordinary shares, nominal value of $0.000273235 per share; 1,795,158 shares issued and outstanding as of March 31, 2026 and December 31, 2025 | 1 | 1 |
| &nbsp;&nbsp;&nbsp;&nbsp;Class A1 ordinary shares, nominal value of $0.000273235 per share; 12,781,964 shares issued and outstanding as of March 31, 2026 and December 31, 2025 | 4 | 4 |
| &nbsp;&nbsp;&nbsp;&nbsp;Class B1 ordinary shares, $0.000273235 nominal value; 16,057,618 shares issued and outstanding as of March 31, 2026 and December 31, 2025 | 4 | 4 |
| &nbsp;&nbsp;&nbsp;&nbsp;Additional paid-in capital | 1045877 | 1029748 |
| &nbsp;&nbsp;&nbsp;&nbsp;Accumulated other comprehensive loss | (665) | (25) |
| &nbsp;&nbsp;&nbsp;&nbsp;Accumulated deficit | (439546) | (462138) |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Total shareholders' equity | 605687 | 567606 |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Total liabilities and shareholders' equity  | $825280 | $763633 |

---

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

[**Table of Contents**](#TOC)

#### KINIKSA PHARMACEUTICALS INTERNATIONAL, PLC

#### CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME
**(In thousands, except share and per share amounts)**

**(Unaudited)**

---

| | | |
|:---|:---|:---|
|  | **Three Months Ended**  | **Three Months Ended**  |
|  | **March 31,**  | **March 31,**  |
|  | **2026** | **2025** |
| Revenue: |  |  |
| &nbsp;&nbsp;&nbsp;&nbsp;Product revenue, net | $214266 | $137785 |
| &nbsp;&nbsp;&nbsp;&nbsp;License and collaboration revenue |  |  |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Total revenue | 214266 | 137785 |
| Costs and operating expenses: |  |  |
| &nbsp;&nbsp;&nbsp;&nbsp;Cost of goods sold | 20796 | 17868 |
| &nbsp;&nbsp;&nbsp;&nbsp;Collaboration expenses | 75577 | 43790 |
| &nbsp;&nbsp;&nbsp;&nbsp;Research and development | 27475 | 19325 |
| &nbsp;&nbsp;&nbsp;&nbsp;Selling, general and administrative | 61151 | 43530 |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Total operating expenses | 184999 | 124513 |
| Income from operations | 29267 | 13272 |
| Other income, net | 3414 | 2293 |
| Income before income taxes | 32681 | 15565 |
| Provision for income taxes | (10089) | (7026) |
| Net income | $22592 | $8539 |
| Net income per share attributable to ordinary shareholders—basic | $0.30 | $0.12 |
| Net income per share attributable to ordinary shareholders—diluted | $0.27 | $0.11 |
| Weighted average ordinary shares outstanding—basic | 76516535 | 72647121 |
| Weighted average ordinary shares outstanding—diluted | 82409703 | 76145617 |
| Comprehensive income |  |  |
| Net income | $22592 | $8539 |
| Other comprehensive loss |  |  |
| &nbsp;&nbsp;&nbsp;&nbsp;Unrealized loss on short-term investments and currency translation adjustments, net of tax | (640) | (2) |
| Total other comprehensive loss | (640) | (2) |
| &nbsp;&nbsp;&nbsp;&nbsp;Total comprehensive income | $21952 | $8537 |

---

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

[**Table of Contents**](#TOC)

#### KINIKSA PHARMACEUTICALS INTERNATIONAL, PLC
**CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY**

**(In thousands, except share amounts)**

**(Unaudited)**

---

| | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|
|  | **Ordinary Shares** | **Ordinary Shares** | | | | |
|  | **(Class A, B, A1 and B1)** | **(Class A, B, A1 and B1)** | | | | |
|  | **Shares** | **Amount** | **Additional**<br>**Paid-In**<br>**Capital** | **Accumulated** <br>**Other Comprehensive**<br>**Loss** | <br>**Accumulated**<br>**Deficit** | **Total**<br>**Shareholders'**<br>**Equity** |
| **Balances at December 31, 2025** | 76294164 | $21 | $1029748 | $(25) | $(462138) | $567606 |
| Issuance of Class A ordinary shares under incentive award plans  | 395296 |  | 6073 |  |  | 6073 |
| Share-based compensation expense |  |  | 10056 |  |  | 10056 |
| Unrealized loss on short-term investments and currency translation adjustments, net of tax |  |  |  | (640) |  | (640) |
| Net income |  |  |  |  | 22592 | 22592 |
| **Balances at March 31, 2026** | 76689460 | $21 | $1045877 | $(665) | $(439546) | $605687 |
|  | **Ordinary Shares** | **Ordinary Shares** | **Additional** | **Accumulated**  |  | **Total** |
|  | **(Class A, B, A1 and B1)** | **(Class A, B, A1 and B1)** | **Paid-In** | **Other Comprehensive** | **Accumulated** | **Shareholders'** |
|  | **Shares** | **Amount** | **Capital** | **Loss** | **Deficit** | **Equity** |
| **Balances at December 31, 2024** | 72516059 | $20 | $959722 | $(163) | $(521143) | $438436 |
| Issuance of Class A ordinary shares under incentive award plans  | 281273 |  | 2768 |  |  | 2768 |
| Share-based compensation expense |  |  | 7748 |  |  | 7748 |
| Unrealized loss on short-term investments and currency translation adjustments, net of tax |  |  |  | (2) |  | (2) |
| Net income |  |  |  |  | 8539 | 8539 |
| **Balances at March 31, 2025** | 72797332 | $20 | $970238 | $(165) | $(512604) | $457489 |

---

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

[**Table of Contents**](#TOC)

#### CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS
**(In thousands)**

**(Unaudited)**

---

| | | |
|:---|:---|:---|
|  | **Three Months Ended**  | **Three Months Ended**  |
|  | **March 31,**  | **March 31,**  |
|  | **2026** | **2025** |
| **Cash flows from operating activities:** |  |  |
| Net income | $22592 | $8539 |
| Adjustments to reconcile net income to net cash provided by operating activities |  |  |
| &nbsp;&nbsp;&nbsp;&nbsp;Depreciation and amortization expense | 468 | 345 |
| &nbsp;&nbsp;&nbsp;&nbsp;Share-based compensation expense | 10056 | 7748 |
| &nbsp;&nbsp;&nbsp;&nbsp;Non-cash lease expense | 994 | 835 |
| &nbsp;&nbsp;&nbsp;&nbsp;Net amortization of premiums and accretion of discounts on short-term investments | 1302 | 255 |
| &nbsp;&nbsp;&nbsp;&nbsp;Net gain on disposal of property and equipment  | (54) | 10 |
| &nbsp;&nbsp;&nbsp;&nbsp;Deferred income taxes | 4523 | 2993 |
| &nbsp;&nbsp;&nbsp;&nbsp;Changes in operating assets and liabilities: |  |  |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Prepaid expenses and other current assets | 13049 | (5327) |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Accounts receivable, net | (7630) | 1659 |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Inventory | (18246) | 4295 |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Other long-term assets | 125 | 2045 |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Accounts payable | 22266 | 62 |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Accrued expenses, accrued collaboration expenses and other current liabilities | (5047) | (3596) |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Operating lease liabilities | (993) | (852) |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Other long-term liabilities | 6794 | 3313 |
| &nbsp;&nbsp;&nbsp;&nbsp;Net cash provided by operating activities | 50199 | 22324 |
| **Cash flows from investing activities:** |  |  |
| Purchases of property and equipment | (161) | (99) |
| Purchases of short-term investments | (177411) | (95470) |
| Proceeds from the maturities of short-term investments | 145656 | 44028 |
| &nbsp;&nbsp;&nbsp;&nbsp;Net cash used in investing activities | (31916) | (51541) |
| **Cash flows from financing activities:** |  |  |
| Proceeds from issuance of Class A ordinary shares under incentive award plans and employee share purchase plan | 6389 | 3180 |
| Payments in connection with ordinary shares tendered for employee tax obligations | (316) | (412) |
| &nbsp;&nbsp;&nbsp;&nbsp;Net cash provided by financing activities | 6073 | 2768 |
| **Net increase (decrease) in cash and cash equivalents** | 24356 | (26449) |
| Cash and cash equivalents at beginning of period | 165596 | 183581 |
| Cash and cash equivalents at end of period | $189952 | $157132 |
| **Supplemental information:** |  |  |
| Cash paid for income taxes | $— | $3008 |
| **Supplemental disclosure of non-cash investing and financing activities:** |  |  |
| Change in right-of-use asset as a result of new, modified, and terminated leases | $521 | $912 |
| Additions to property and equipment included in accrued expenses and other liabilities | 108 | 34 |

---

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

[**Table of Contents**](#TOC)

1.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Nature of the Business and Basis of Presentation

Kiniksa Pharmaceuticals International, plc (the "Company") is a biopharmaceutical company developing and commercializing novel therapies for diseases with unmet need, with a focus on cardiovascular indications. The Company's portfolio of immune-modulating assets is based on strong biologic rationale or validated mechanisms, targets a spectrum of underserved cardiovascular and autoimmune conditions and offers the potential for differentiation.

The Company is subject to risks common to companies in the biopharmaceuticals industry including, but not limited to, commercialization of existing and new products, conducting clinical research and development, its current and future products and product candidates, risks from existing or new competition, protection of proprietary intellectual and other technology and compliance with United States and foreign regulations and approval requirements.

#### Unaudited Interim Condensed Consolidated Financial Information
The accompanying unaudited condensed consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP") for interim financial information. The accompanying unaudited condensed consolidated financial statements do not include all of the information and footnotes required by GAAP for complete consolidated financial statements. The information included in this Quarterly Report on Form 10-Q should be read in conjunction with the Company's audited consolidated financial statements and the accompanying notes included in the Company's Annual Report on Form 10-K for the year ended December 31, 2025 (the "2025 Form 10-K"). The Company's accounting policies are described in the Notes to Consolidated Financial Statements included in the Company's 2025 Form 10-K and updated, as necessary, in this report. The accompanying year-end condensed consolidated balance sheet was derived from audited financial statements but does not include all disclosures required by GAAP. The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited annual consolidated financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for the fair statement of the Company's financial position as of March 31, 2026 and the results of its operations for the three months ended March 31, 2026 and 2025, the changes in its shareholders' equity for the three months ended March 31, 2026 and 2025 and its cash flows for the three months ended March 31, 2026 and 2025. The results for the three months ended March 31, 2026 are not necessarily indicative of results to be expected for the year ending December 31, 2026, any other interim periods or any future year or period.

#### 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, *Intangibles—Goodwill and Other—Internal-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 years, with early adoption permitted. The guidance is required to be applied prospectively, with optional retrospective or modified retrospective transition methods. The Company is currently evaluating the impact of ASU 2025-06 on its consolidated financial statements.

[**Table of Contents**](#TOC)

***Recently Adopted Accounting Pronouncements***

In September 2025, the FASB issued ASU *2025-07*, *Derivatives and Hedging (Topic 815) and Revenue from Contracts with Customers (Topic 606): Derivatives Scope Refinements and Scope Clarification for Share-Based Noncash Consideration from a Customer in a Revenue Contract*, which refines the scope of derivative accounting and clarifies the treatment of certain share-based noncash consideration in revenue contracts. The Company adopted this ASU in the first quarter of 2026, prospectively. The adoption of this ASU did not have a material effect on the Company's consolidated financial statements.

2.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 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 1—Quoted prices in active markets for identical assets or liabilities.

● Level 2—Observable 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 3—Unobservable 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 Company's 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** | **Fair Value Measurements** | **Fair Value Measurements** | **Fair Value Measurements** |
|  | **as of March 31, 2026 Using:** | **as of March 31, 2026 Using:** | **as of March 31, 2026 Using:** | **as of March 31, 2026 Using:** |
|  | **Level 1** | **Level 2** | **Level 3** | **Total** |
| Assets: |  |  |  |  |
| &nbsp;&nbsp;Cash equivalents — money market funds | $69287 | $— | $— | $69287 |
| &nbsp;&nbsp;Cash equivalents — U.S. Treasury Securities |  | 14427 |  | 14427 |
| &nbsp;&nbsp;Short-term investments — U.S. Treasury Securities |  | 278141 |  | 278141 |
|  | $69287 | $292568 | $— | $361855 |

---

---

| | | | | |
|:---|:---|:---|:---|:---|
|  | **Fair Value Measurements** | **Fair Value Measurements** | **Fair Value Measurements** | **Fair Value Measurements** |
|  | **as of December 31, 2025 Using:** | **as of December 31, 2025 Using:** | **as of December 31, 2025 Using:** | **as of December 31, 2025 Using:** |
|  | **Level 1** | **Level 2** | **Level 3** | **Total** |
| Assets: |  |  |  |  |
| &nbsp;&nbsp;Cash equivalents — money market funds | $77291 | $— | $— | $77291 |
| &nbsp;&nbsp;Short-term investments — U.S. Treasury Securities |  | 248478 |  | 248478 |
|  | $77291 | $248478 | $— | $325769 |

---

During the three months ended March 31, 2026 and the year ended December 31, 2025, 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 Company's cash equivalents and short-term investments as of March 31, 2026 and December 31, 2025 included U.S. 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.

[**Table of Contents**](#TOC)

The contractual maturities of short-term investments were as follows:

---

| | | |
|:---|:---|:---|
|  | **March 31,** <br>**2026** | **December 31,**<br>**2025** |
| Maturities within one year | $128045 | $179577 |
| Maturities after one year through five years | 150096 | 68901 |
| &nbsp;&nbsp;Total | $278141 | $248478 |

---

The following tables summarize short-term investments:

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | <br>**Amortized**<br>**Cost** | **Gross**<br>**Unrealized** <br>**Gains** | **Gross**<br>**Unrealized** <br>**Losses** | <br>**Credit**<br>**Losses** | <br>**Fair** <br>**Value** |
| March 31, 2026 |  |  |  |  |  |
| &nbsp;&nbsp;Cash Equivalents - U.S. Treasury Securities | $14427 | $— | $— | $— | $14427 |
| &nbsp;&nbsp;Short-term investments — U.S. Treasury Securities | 278806 | 15 | (680) |  | 278141 |
|  | $293233 | $15 | $(680) | $— | $292568 |

---

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | <br>**Amortized**<br>**Cost** | **Gross**<br>**Unrealized** <br>**Gains** | **Gross**<br>**Unrealized** <br>**Losses** | <br>**Credit**<br>**Losses** | <br>**Fair** <br>**Value** |
| December 31, 2025 |  |  |  |  |  |
| &nbsp;&nbsp;Short-term investments — U.S. Treasury Securities | $248354 | $125 | $(1) | $— | $248478 |
|  | $248354 | $125 | $(1) | $— | $248478 |

---

As of March 31, 2026, the Company considers the unrealized losses in its investment portfolio to be temporary in nature and not due to credit losses. The Company has the ability to hold such investments until recovery of the fair value. The Company utilizes the specific identification method in computing realized gains and losses. The Company had no realized gains and losses on its available-for-sale securities for the three months ended March 31, 2026 or 2025.

3.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 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** | **Three Months Ended** |
|  | **March 31,**  | **March 31,**  |
|  | **2026** | **2025** |
| Product revenue, net | $214266 | $137785 |

---

[**Table of Contents**](#TOC)

The following table summarizes balances and activity in each of the product revenue allowance and reserve categories for the three months ended March 31, 2026:

---

| | | | | |
|:---|:---|:---|:---|:---|
|  | **Contractual**<br>**Adjustments** | **Government**<br>**Rebates** | <br>**Returns** | <br>**Total** |
| Balance at December 31, 2025 | $4559 | $11883 | $3124 | $19566 |
| &nbsp;&nbsp;Current provisions relating to sales in the current year | 11733 | 8633 | 546 | 20912 |
| &nbsp;&nbsp;Adjustments relating to prior years |  | (671) |  | (671) |
| &nbsp;&nbsp;Payments/returns relating to sales in the current year | (10287) | (3675) |  | (13962) |
| &nbsp;&nbsp;Payments/returns relating to sales in the prior years | (4537) | (3300) |  | (7837) |
| Balance at March 31, 2026 | $1468 | $12870 | $3670 | $18008 |

---

Total revenue-related reserves as of March 31, 2026 and December 31, 2025, included in the Company's condensed consolidated balance sheets, are summarized as follows:

---

| | | |
|:---|:---|:---|
|  | **March 31,** <br>**2026** | **December 31,** <br>**2025** |
| Components of accounts receivable | $(1339) | $(831) |
| Components of other current liabilities | 19347 | 20397 |
| Total revenue-related reserves | $18008 | $19566 |

---

Substantially all of the Company's trade accounts receivable arise from product revenue in the United States due from the Company's third party logistics provider.

4.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Inventory

Inventory consisted of the following:

---

| | | |
|:---|:---|:---|
|  | **March 31,** <br>**2026** | **December 31,**<br>**2025** |
| Raw materials | $10448 | $9968 |
| Semi-finished goods | 53407 | 29399 |
| Finished goods | 14313 | 20555 |
| &nbsp;&nbsp;Total inventory | $78168 | $59922 |
| Balance Sheet Classification:  |  |  |
| Inventory  | $73141 | $54895 |
| Other long-term assets | 5027 | 5027 |
| &nbsp;&nbsp;Total inventory  | $78168 | $59922 |

---

As of March 31, 2026, $21,063 of semi-finished goods were associated with the Company's technology transfer of ARCALYST drug substance manufacturing to a new facility, which is pending regulatory approval. The Company believes it is probable that regulatory approval will be obtained, and all such inventory will be available for commercial distribution in the future.

[**Table of Contents**](#TOC)

5.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Property and Equipment, Net

Property and equipment, net consisted of the following:

---

| | | |
|:---|:---|:---|
|  | **March 31,** <br>**2026** | **December 31,** <br>**2025** |
| Furniture, fixtures and vehicles | $177 | $177 |
| Computer hardware and software | 96 | 96 |
| Leasehold improvements | 4639 | 4639 |
| Lab equipment  | 4148 | 4006 |
| Construction in progress | 300 | 255 |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Total property and equipment | 9360 | 9173 |
| Less: Accumulated depreciation | (7374) | (7230) |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Total property and equipment, net | $1986 | $1943 |

---

Depreciation expense was $144 and $35 during the three months ended March 31, 2026 and 2025, respectively.

6.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Intangible Assets

Intangible assets, net of accumulated amortization as of March 31, 2026 and December 31, 2025 are summarized in the following table.

---

| | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|
|  | | **As of March 31, 2026** | **As of March 31, 2026** | **As of March 31, 2026** | **As of December 31, 2025** | **As of December 31, 2025** | **As of December 31, 2025** |
|  | <br>**Estimated**<br>**life** | <br>**Cost** | **Accumulated**<br>**Amortization** | <br>**Net** | <br>**Cost** | **Accumulated**<br>**Amortization** | <br>**Net** |
| Regulatory milestone | 20 years | $20000 | $5000 | $15000 | $20000 | $4750 | $15250 |

---

Amortization expense was $250 during the three months ended March 31, 2026 and 2025.

7.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Accrued Expenses

Accrued expenses consisted of the following:

---

| | | |
|:---|:---|:---|
|  | **March 31,** <br>**2026** | **December 31,** <br>**2025** |
| Accrued employee compensation and benefits | $14269 | $21437 |
| Accrued inventory and manufacturing  | 2988 | 8008 |
| Accrued research and development expenses | 9202 | 6629 |
| Accrued legal, commercial and professional fees | 5834 | 5348 |
| Other | 478 | 598 |
|  | $32771 | $42020 |

---

8.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 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 March 31, 2026, there were 574,902 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.

[**Table of Contents**](#TOC)

***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 Plan's 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 March 31, 2026, 8,764,119 shares remained available for future grant under the 2018 Plan.

***2018 ESPP***

In December 2025, the Company's board of directors approved an increase, as of January 1, 2026, of 110,000 Class A ordinary shares under the 2018 ESPP. As of March 31, 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 employees as part of its equity incentive compensation. Such RSUs typically vest 25% on each of the first, second, third and fourth anniversaries of the date of grant, subject to continued employment through such dates.

***Market and Performance-Based Share Units***

In 2024, the Company began periodically granting performance-based restricted share units to certain employees under the 2018 Plan that are earned based upon (i) the achievement of certain specified ARCALYST revenue targets ("Revenue PSUs") and (ii) the Company's total shareholder return ("TSR") relative to the TSR of each member of a specified peer group ("TSR PSUs"). The TSR PSUs and Revenue PSUs are subject to a three-year service period.

In addition, the Company from time-to-time grants performance-based restricted share units to certain eligible employees pursuant to the 2018 Plan that are earned based upon certain development and regulatory milestones ("Development PSUs" and, together with the Revenue PSUs and TSR PSUs, "PSUs"). The Company's currently outstanding Development PSUs are subject to earnout percentages based upon the date of applicable milestone achievement.

***Performance Share Options***

Beginning in the second quarter of 2025, the Company began granting performance share options ("PSOs") to certain eligible employees pursuant to the 2018 Plan representing the right to purchase shares of the Company's Class A ordinary shares. Such PSOs vest, if at all, upon the achievement of certain specified development and regulatory milestones and are subject to earnout percentages based upon the date of applicable milestone achievement.

The following table summarizes RSU and PSU activity for the three months ended March 31, 2026:

---

| | | | | |
|:---|:---|:---|:---|:---|
|  | **RSUs** | **RSUs** | **PSUs** | **PSUs** |
|  |  | **Weighted** |  | **Weighted** |
|  |  | **Average** |  | **Average** |
|  | **Number of** | **Grant Date** | **Number of** | **Grant Date** |
|  | **Shares** | **Fair Value** | **Shares** | **Fair Value** |
| Unvested as of December 31, 2025 | 2074095 | $23.09 | 415307 | $27.25 |
| &nbsp;&nbsp;Granted | 45951 | $43.01 | 10854 | $43.62 |
| &nbsp;&nbsp;Vested | (21474) | $18.07 | - | $— |
| &nbsp;&nbsp;Forfeited | (90891) | $24.26 | (5154) | $27.36 |
| Unvested as of March 31, 2026 | 2007681 | $23.55 | 421007 | $27.67 |

---

[**Table of Contents**](#TOC)

The following table summarizes share option and PSO activity for the three months ended March 31, 2026:

---

| | | | | |
|:---|:---|:---|:---|:---|
|  | **Options** | **Options** | **PSOs** | **PSOs** |
|  |  | **Weighted** |  | **Weighted** |
|  | **Number of** | **Average** | **Number of** | **Average** |
|  | **Shares** | **Exercise Price** | **Shares** | **Exercise Price** |
| Outstanding as of December 31, 2025 | 9420208 | $18.61 | 299706 | $28.50 |
| &nbsp;&nbsp;Granted | 48016 | $42.93 | 17995 | $43.63 |
| &nbsp;&nbsp;Exercised | (347440) | $15.91 |  | $— |
| &nbsp;&nbsp;Forfeited | (102260) | $26.24 | (8239) | $27.36 |
| Outstanding as of March 31, 2026 | 9018524 | $18.76 | 309462 | $29.41 |
| Share options exercisable as of March 31, 2026 | 6138732 | $15.93 |  | $— |
| Share options vested and expected to vest as of March 31, 2026 | 9018524 | $18.76 | 309462 | $29.41 |

---

As of March 31, 2026, total unrecognized compensation cost related to RSUs, Revenue PSUs, TSR PSUs, and share options was $93,014 which is expected to be recognized over a weighted average remaining period of 2.35 years. As of March 31, 2026, total unrecognized compensation cost related to outstanding Development PSUs and PSOs was $10,241 which will be recognized when the applicable milestones are deemed probable of achievement through the date the awards vest with a cumulative catch-up.

***Share-Based Compensation***

Share-based compensation expense was classified in the condensed consolidated statements of operations and comprehensive income as follows:

---

| | | |
|:---|:---|:---|
|  | **Three Months Ended**  | **Three Months Ended**  |
|  | **March 31,**  | **March 31,**  |
|  | **2026** | **2025** |
| Cost of goods sold | $518 | $429 |
| Research and development expenses | 1629 | 1502 |
| Selling, general and administrative expenses | 7909 | 5817 |
|  | $10056 | $7748 |

---

9. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Out-Licensing Agreements

***Genentech License Agreement***

In the third quarter of 2022 (the "Genentech Effective Date"), the Company entered into a license agreement (the "Genentech License Agreement") with Genentech, Inc. and F. Hoffmann-La Roche Ltd (collectively, "Genentech"), pursuant to which the Company granted Genentech exclusive worldwide rights to develop, manufacture and commercialize vixarelimab and related antibodies (each, a "Genentech Licensed Product").

Under the terms of the Genentech License Agreement, the Company is eligible to receive a total of approximately $600,000 in contingent payments, including specified development, regulatory and sales-based milestones, before fulfilling the Company's upstream financial obligations, of which approximately $570,000 remain as of March 31, 2026. The Company will also be eligible to receive tiered percentage royalties on a Genentech Licensed Product-by-Genentech Licensed Product basis ranging from low-double digits to mid-teens on annual net sales of each Genentech Licensed Product, subject to certain customary reductions, with an aggregate minimum floor, before fulfilling the Company's upstream financial obligations. Royalties will be payable on a Genentech Licensed Product-by-Genentech Licensed Product and country-by-country basis until the latest to occur of the expiration of certain patents that cover a Genentech Licensed Product, the expiration of regulatory exclusivity for such Genentech Licensed Product, or the tenth anniversary of first commercial sale of such Genentech Licensed Product in such country.

[**Table of Contents**](#TOC)

Pursuant and subject to the terms of the Genentech License Agreement, Genentech has the exclusive worldwide right to conduct development and commercialization activities for Genentech Licensed Products at its sole cost. In 2024, the Company fulfilled its responsibility under the Genentech License Agreement with respect to completing its Phase 2b clinical trial assessing the efficacy, safety and tolerability of vixarelimab in reducing pruritus in prurigo nodularis.

*Accounting for the Genentech License Agreement*

As of the Genentech Effective Date, the Company identified the following performance obligations in the Genentech License Agreement: (i) the delivery of the exclusive license for vixarelimab; (ii) an initial drug supply delivery; (iii) a drug product resupply delivery; and (iv) completion of the Phase 2b clinical trial for vixarelimab.

The selling price of each performance obligation in the Genentech License Agreement was determined based on the Company's standalone selling price with the objective of determining the price at which it would sell such an item if it were to be sold regularly on a standalone basis. The Company allocated the transaction price to each of the four performance obligations noted above, all of which were satisfied as of June 30, 2024.

The Company determined that all other variable considerations related to the future development and regulatory milestones, are deemed fully constrained and therefore excluded from the transaction price due to the high degree of uncertainty and risk associated with these potential payments, as the Company also determined that it could not assert that it was not probable that a significant reversal in the amount of cumulative revenue recognized would occur. The Company also determined that royalties and sales milestones relate solely to the license of intellectual property. Revenue related to these royalties and sales milestones will only be recognized when the associated sales occur, and relevant thresholds are met, under the sales or usage-based royalty exception of Topic 606.

The Company did not recognize any collaboration revenue under the Genentech License Agreement during the three months ended March 31, 2026 and 2025. As of March 31, 2026, the Company had recognized the entire transaction price under the Genentech License Agreement as revenue.

***Huadong Collaboration Agreement***

In February 2022 (the "Effective Date"), the Company entered into a collaboration and license agreement (the "Huadong Collaboration Agreement") with Hangzhou Zhongmei Huadong Pharmaceutical Co., Ltd. ("Huadong"), pursuant to which the Company granted Huadong exclusive rights to develop and commercialize ARCALYST in a territory, which currently includes the following countries: People's Republic of China, Hong Kong SAR, Macao SAR, Taiwan Region, Indonesia, The Philippines, Thailand, Bangladesh, Bhutan, Brunei, Burma, Cambodia, India, Laos, Malaysia, Maldives, Mongolia, Nepal, New Zealand, Sri Lanka, and Vietnam (collectively, the "Huadong Territory"). The Company otherwise retained its current rights to ARCALYST outside the Huadong Territory.

Under the Huadong Collaboration Agreement, the Company received a total upfront cash payment of $12,000 for the Huadong Territory license of ARCALYST. In 2024, following the achievement of a regulatory milestone under the Huadong Collaboration Agreement, Huadong became obligated to make an additional cash payment of $20,000 to the Company. The Company will be eligible to receive up to approximately $50,000 in contingent sales-based milestone payments for ARCALYST, all of which remain outstanding as of March 31, 2026. Huadong will also be obligated to pay the Company tiered percentage royalties ranging from the low-to-mid teens on annual net sales of ARCALYST in the Huadong Territory, subject to certain reductions tied to ARCALYST manufacturing costs and certain other customary reductions, with an aggregate minimum floor. Royalties will be payable on ARCALYST on a country-by-country or region-by-region basis until the later of (i) 12 years after the first commercial sale of ARCALYST in such country or region in the Huadong Territory, (ii) the date of expiration of the last valid patent claim of the Company's patent rights or any joint collaboration patent rights that covers ARCALYST in such country or region in the Huadong Territory, and (iii) the expiration of the last regulatory exclusivity for ARCALYST in such country or region in the Huadong Territory.

[**Table of Contents**](#TOC)

*Accounting for the Huadong Collaboration Agreement*

As of the Effective Date, the Company identified one performance obligation in the Huadong Collaboration Agreement: the exclusive license for ARCALYST and clinical and commercial manufacturing obligations for ARCALYST products in the Huadong Territory. Huadong cannot exploit the value of the exclusive license for ARCALYST products in the Huadong Territory without receipt of supply as the exclusive license for ARCALYST products in the Huadong Territory does not convey to Huadong the right to manufacture and therefore the Company has combined the exclusive license for ARCALYST products in the Huadong Territory and the manufacturing obligations into one performance obligation.

The Company determined the transaction price at the inception of the Huadong Collaboration Agreement, which includes $12,000, consisting of the upfront payment. In 2024, the Company added $20,000 to the transaction price following the achievement of a regulatory milestone. The Company also includes an estimate of variable consideration associated with the clinical and commercial manufacturing supply of certain materials when those materials are shipped. The Company determined that any variable consideration related to development and regulatory milestones, sales milestones and royalties are deemed fully constrained and therefore excluded from the transaction price due to the high degree of uncertainty and risk associated with these potential payments, as the Company determined that it could not assert that it was probable that a significant reversal in the amount of cumulative revenue recognized will not occur. Royalties and sales milestones will be recognized as the Company delivers the commercial manufactured product to Huadong. Any changes in estimates may result in a cumulative catch-up based on the number of units of manufactured product delivered.

The Company recognizes revenue for the single performance obligation in the Huadong Collaboration Agreement consisting of the exclusive license for ARCALYST and clinical and commercial manufacturing obligations for ARCALYST products in the Huadong Territory at a point in time, upon which control of materials are transferred to Huadong for each delivery of the associated materials. The Company currently expects to recognize the revenue over the life of the agreement. This estimate considers the timing of development and commercial activities under the Huadong Collaboration Agreement and may be reduced or increased based on changes in the various activities.

The Company did not recognize any revenue under the Huadong Collaboration Agreement during the three months ended March 31, 2026 and 2025. As of March 31, 2026, $31,811 of the transaction price is recorded in non-current deferred revenue, based upon timing of anticipated future shipments.

The following table summarizes the Company's contract liabilities in connection with license and collaboration agreements for the three months ended March 31, 2026:

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Balance at**<br>**Beginning of Period** | <br>**Additions** | **Revenue**<br>**Recognized** | <br>**Reclassification** | **Balance at End**<br>**of Period** |
| **Three Months Ended March 31, 2026** |  |  |  |  |  |
| Contract Liabilities:  |  |  |  |  |  |
| &nbsp;&nbsp;Huadong ARCALYST | $31811 | $— | $— | $— | $31811 |

---

10.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; License and Acquisition Agreements

***Regeneron License Agreement***

In September 2017, the Company entered into a license agreement (the "Regeneron Agreement") with Regeneron Pharmaceuticals, Inc. ("Regeneron"), pursuant to which the Company has been granted an exclusive license under certain intellectual property rights controlled by Regeneron to develop and commercialize ARCALYST worldwide, excluding the Middle East and North Africa, for all indications other than those in oncology and local administration to the eye or ear. Upon receiving positive data in RHAPSODY, the Company's pivotal Phase 3 clinical trial of ARCALYST, Regeneron transferred the biologics license application ("BLA") for ARCALYST to the Company. In March 2021, when the FDA granted approval of ARCALYST for the treatment of recurrent pericarditis and reduction

[**Table of Contents**](#TOC)

in risk of recurrence in adults and children 12 years and older, the Company assumed the sales and distribution of ARCALYST for Cryopyrin-Associated Periodic Syndromes and Deficiency of Interleukin-1 Receptor Antagonist in the United States.

The Company evenly splits profits on sales of ARCALYST with Regeneron, where profits are determined after deducting from net sales of ARCALYST certain costs related to the manufacturing and commercialization of ARCALYST. Such costs include but are not limited to (i) the Company's cost of goods sold for product used, sold or otherwise distributed for patient use by the Company; (ii) customary commercialization expenses, including the cost of the Company's field force, and (iii) the Company's cost to market, advertise and otherwise promote ARCALYST, with such costs identified in subsection (iii) subject to specified limits. To the extent permitted in accordance with the Regeneron Agreement, the fully-burdened costs incurred by each of the Company and Regeneron in performing (or having performed) the technology transfer of the manufacturing process for ARCALYST drug substance will also be deducted from net sales of ARCALYST to determine profit. The Company also evenly splits with Regeneron any proceeds received by the Company from any licensees, sublicensees and distributors in consideration for the sale, license or other disposition of rights with respect to ARCALYST, including upfront payments, milestone payments and royalties. For the three months ended March 31, 2026 and 2025, the Company recognized $75,577 and $43,775 respectively, of expenses related to the profit sharing agreement presented within collaboration expenses.

The Company has a supply agreement with Regeneron pursuant to which the Company may order both clinical and commercial product. The supply agreement terminates upon the termination of the Regeneron Agreement or the date of completion of the transfer of technology related to the manufacture of ARCALYST. During the three months ended March 31, 2026 and 2025, the Company did not incur any research and development expense related to the purchase of drug materials under the supply agreement. As of March 31, 2026 and December 31, 2025, the Company recorded inventory of $46,657 and $29,071 respectively, related to the purchase of commercial product under the supply agreement. As of March 31, 2026, the Company had non-cancelable purchase commitments under the supply agreement (see Note 13).

The Regeneron Agreement will expire when the Company is no longer developing or commercializing any licensed product under the Regeneron Agreement. Either party may terminate the agreement upon the other party's insolvency or bankruptcy or for material breach of the agreement by the other party that remains uncured for 90 days (or 30 days for payment related breaches). Regeneron has the right to terminate the agreement if the Company suspends its development or commercialization activities for a consecutive 12 month period or does not grant a sublicense to a third party to perform such activities, or if the Company challenges any of the licensed patent rights. The Company may terminate the agreement at any time with one year's written notice. The Company may also terminate the agreement with three months' written notice if the licensed product is determined to have certain safety concerns.

#### Biogen Asset Purchase Agreement
In September 2016, the Company entered into an asset purchase agreement (the "Biogen Agreement") with Biogen MA Inc. ("Biogen") to acquire all of Biogen's right, title and interest in and to certain assets used in or relating to vixarelimab and other antibodies covered by certain patent rights, including patents and other intellectual property rights, clinical data, know-how, and clinical drug supply. In addition, Biogen granted the Company a non-exclusive, sublicensable, worldwide license to certain background patent rights related to the vixarelimab program. The Company is obligated to use commercially reasonable efforts to develop and commercialize such acquired products.

In exchange for these rights, the Company made upfront payments to Biogen of $12,000. The Company recorded the upfront payments as research and development expense in the consolidated statement of operations and comprehensive income because the acquired technology represented in-process research and development and had no alternative future use.

Under the Biogen Agreement, the Company is obligated to make milestone payments to Biogen of up to $179,000 upon the achievement of specified clinical and regulatory milestones in multiple indications in various territories, of which $165,000 remains as of March 31, 2026. Additionally, the Company could be obligated to make up to an aggregate of $150,000 of payments upon the achievement of specified annual net sales milestones and to pay tiered

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royalties on escalating tiers of annual net sales of licensed products starting in the high single-digit percentages and ending below the teens.

The Company also agreed to pay certain obligations under third party contracts retained by Biogen that relate to the vixarelimab program. Under these retained contracts, the Company paid a one-time upfront sublicense fee of $150 and is obligated to pay insignificant annual maintenance fees as well as clinical and regulatory milestone payments of up to an aggregate of $1,575.

The Biogen Agreement will terminate upon the expiration of all payment obligations with respect to the last product in all countries in the territory. The Company has the right to terminate the agreement with 90 days' prior written notice. Both parties may terminate by mutual written consent or in the event of material breach of the agreement by the other party that remains uncured for 90 days (or 30 days for payment-related breaches).

The Company and Biogen have amended the Biogen Agreement twice following its initial effective date. The first amendment, in July 2017, clarified the scope of the antibodies subject to the Biogen Agreement. The second amendment, effective in August 2022, was entered into in connection with the Genentech License Agreement, and amended certain defined terms, including "Net Sales," "Indication," "Product," "Combination Product" and "Valid Claim." In addition, the tiered royalty rates to be paid by the Company to Biogen increased by an amount equal to less than one percent. Upon the termination or expiration of the Genentech License Agreement all terms of the Biogen Agreement will revert to the version of such terms in effect as of immediately prior to the effective date of the Genentech License Agreement.

During the three months ended March 31, 2026, the Company did not record any expenses in connection with the Biogen Agreement. During the three months ended March 31, 2025, the Company recorded expenses of $14 related to a milestone and the annual maintenance fee in connection with the Biogen Agreement.

***Other Agreements***

In 2019, the Company acquired certain other intellectual property through the acquisition of all of the outstanding securities of the company that owned or controlled such intellectual property. Under this agreement, the Company is solely responsible for all development, regulatory and commercial activities and costs. The Company is also responsible for costs related to filing, prosecuting and maintaining the licensed patent rights. Under this agreement, the Company is obligated to pay an insignificant annual maintenance fee as well as clinical and regulatory milestone payments of up to an aggregate of $1,200. The Company is also obligated to pay a low single-digit royalty on annual net sales of products licensed under the agreement.

11.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Net Income per Share

The rights, including the liquidation and dividend rights, of the holders of Class A, Class B, Class A1 and Class B1 ordinary shares are identical, except with respect to voting, transferability and conversion. As the liquidation and dividend rights are identical, losses are allocated on a proportionate basis and the resulting net income per share attributed to ordinary shareholders will, therefore, be the same for both Class A and Class B ordinary shares on an individual or combined basis.

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Basic and diluted net income attributable to ordinary shareholders was calculated as follows:

---

| | | |
|:---|:---|:---|
|  | **Three Months Ended**  | **Three Months Ended**  |
|  | **March 31,**  | **March 31,**  |
|  | **2026** | **2025** |
| Numerator: |  |  |
| &nbsp;&nbsp;Net income attributable to ordinary shareholders | $22592 | $8539 |
| Denominator: |  |  |
| &nbsp;&nbsp;Weighted-average shares outstanding | 76516535 | 72647121 |
| &nbsp;&nbsp;Effect of dilutive securities |  |  |
| &nbsp;&nbsp;&nbsp;&nbsp;Options to purchase ordinary shares | 4568818 | 2689797 |
| &nbsp;&nbsp;&nbsp;&nbsp;Performance options to purchase ordinary shares |  |  |
| &nbsp;&nbsp;&nbsp;&nbsp;Unvested RSUs | 1176866 | 795304 |
| &nbsp;&nbsp;&nbsp;&nbsp;Unvested PSUs | 147484 | 13396 |
| &nbsp;&nbsp;Weighted-average shares outstanding | 82409703 | 76145617 |
| Basic net income per share | $0.30 | $0.12 |
| Diluted net income per share | $0.27 | $0.11 |

---

For the three months ended March 31, 2026 and 2025, diluted earnings per share includes the assumed exercise of dilutive options and the assumed issuance of ordinary shares for unvested RSUs and PSUs for which the market or performance condition has been met as of the date of determination, using the treasury stock method unless the effect is anti-dilutive. The treasury stock method assumes that proceeds, including cash received from the exercise of employee share options and the average unrecognized compensation expense for unvested share-based compensation awards, would be used to purchase the Company's ordinary shares at the average market price during the period.

The Company excluded the following potential ordinary shares, presented based on amounts outstanding at each period end, from the computation of diluted EPS attributable to ordinary shareholders for the periods indicated because including them would have had an anti-dilutive effect:

---

| | | |
|:---|:---|:---|
|  | **Three Months Ended**  | **Three Months Ended**  |
|  | **March 31,**  | **March 31,**  |
|  | **2026** | **2025** |
| Share options to purchase ordinary shares | 915903 | 3507402 |
| Performance share options to purchase ordinary shares |  |  |
| Unvested RSUs | 30213 | 465039 |
| Unvested PSUs |  |  |
| &nbsp;&nbsp;Total anti-dilutive shares | 946116 | 3972441 |

---

PSUs and PSOs that are outstanding and contain performance-based or market-based vesting criteria for which the performance or market conditions have not been met are excluded from the presentation of common stock equivalents outstanding in the table above.

12.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Income Taxes

The Company's income is subject to the enacted UK statutory corporate tax rate. The Company's wholly owned United States subsidiaries, including Kiniksa Pharmaceuticals Corp. ("Kiniksa US"), are subject to federal and state income taxes in the United States. The Company's wholly owned subsidiary Kiniksa Pharmaceuticals (UK), Ltd. ("Kiniksa UK"), and Kiniksa UK's wholly owned subsidiaries, including Kiniksa Pharmaceuticals, GmbH ("Kiniksa Switzerland") and Kiniksa UK's Swiss branch office, are subject to taxation in their respective countries. Certain of the Company's subsidiaries operate under cost plus intercompany arrangements.

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The Company recorded an income tax provision of $10,089 and $7,026 for the three months ended March 31, 2026 and 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 related to share-based compensation, United States federal and state research and development credits ("R&D Credits") and Foreign Derived Intangible Income ("FDII") deduction.

Management regularly assesses the need for a valuation allowance on the Company's deferred income tax assets. Valuation allowances require an assessment of both positive and negative evidence when determining whether it is more likely than not that the Company will be able to recover its deferred tax assets. Such assessment is required on a jurisdiction-by-jurisdiction basis. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which those temporary differences become deductible. The Company maintains a valuation allowance on the full amount of the Kiniksa Switzerland deferred tax assets. There are no material deferred tax assets in the jurisdictions outside the United States, UK and Switzerland.

13.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 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 March 31, 2026, the Company had committed to minimum purchase commitments under all of these agreements totaling $157,324, of which $70,030 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 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 development and regulatory milestones and that are subject to earnout percentages based upon the date of applicable milestone achievement. As of March 31, 2026, the Company estimates the future cash payments under such Performance Cash Awards to be $23,088 if the milestones are achieved at target. The Performance Cash Awards will be recognized when the applicable milestones are deemed probable of achievement with a cumulative catch-up and recognized over the remaining term. The Company has not deemed any of the Performance Cash Award development or regulatory milestones as probable as of March 31, 2026, and no expense has been recognized related to such awards.

#### Indemnification Agreements
The Company is not aware of any claims under indemnification arrangements that are expected to have a material effect on its financial position, results of operations or cash flows, and it has not accrued any liabilities related to such obligations in its condensed consolidated financial statements as of March 31, 2026 or December 31, 2025.

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#### Legal Proceedings
The Company is not a party to any material litigation and does not have contingency reserves established for any litigation liabilities.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;**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 Company's singular focus is on developing and commercializing novel therapies that target cardiovascular diseases with significant unmet medical need. The Company's Chief Operating Decision Maker ("CODM") is the Chief Executive Officer. The Company's 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 Company's commercial product and development programs. The following table presents selected financial information with respect to the Company's single operating segment for the three months ended March 31, 2026 and 2025:

---

| | | |
|:---|:---|:---|
|  | **Three Months Ended**  | **Three Months Ended**  |
|  | **March 31,**  | **March 31,**  |
|  | **2026** | **2025** |
| Revenue: |  |  |
| &nbsp;&nbsp;&nbsp;&nbsp;Product revenue, net | $214266 | $137785 |
| &nbsp;&nbsp;&nbsp;&nbsp;License and collaboration revenue | - | - |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Total revenue | 214266 | 137785 |
| Operating expenses: |  |  |
| &nbsp;&nbsp;&nbsp;&nbsp;Cost of goods sold | 20796 | 17868 |
| &nbsp;&nbsp;&nbsp;&nbsp;Collaboration expenses | 75577 | 43790 |
| &nbsp;&nbsp;&nbsp;&nbsp;Direct research and development expenses by program: |  |  |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;ARCALYST | 341 | 355 |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;KPL-387 | 16152 | 5178 |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;KPL-1161 | 955 | 100 |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Abiprubart  | 53 | 4367 |
| &nbsp;&nbsp;&nbsp;&nbsp;Unallocated research and development expenses | 9974 | 9325 |
| &nbsp;&nbsp;&nbsp;&nbsp;Selling, general and administrative | 61151 | 43530 |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Total operating expenses | 184999 | 124513 |
| Other income, net (1)  | 3414 | 2293 |
| Income before income taxes | 32681 | 15565 |
| Provision for income taxes | (10089) | (7026) |
| Net income | $22592 | $8539 |
| Other significant noncash items:  |  |  |
| &nbsp;&nbsp;Share-based compensation expense | $10056 | $7748 |
| &nbsp;&nbsp;Non-cash lease expense | 994 | 835 |
| &nbsp;&nbsp;Deferred income taxes | 4523 | 2993 |

---

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(1)Includes interest income of $3,414 and $2,290 for the three months ended March 31, 2026 and 2025, respectively.

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The following table presents total revenue by geographic region of the customer for the three months ended March 31, 2026 and 2025:

---

| | | |
|:---|:---|:---|
|  | **Three Months Ended**  | **Three Months Ended**  |
|  | **March 31,**  | **March 31,**  |
|  | **2026** | **2025** |
| Revenue: |  |  |
| &nbsp;&nbsp;&nbsp;&nbsp;United States  | $214068 | $137597 |
| &nbsp;&nbsp;&nbsp;&nbsp;United Kingdom  | 198 | 188 |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Total revenue | $214266 | $137785 |

---

The following table presents property and equipment, net by geographic region (in thousands):

---

| | | |
|:---|:---|:---|
|  | **March 31,** <br>**2026** | **December 31,**<br>**2025** |
| Property and equipment, net |  |  |
| &nbsp;&nbsp;&nbsp;&nbsp;United States  | $1483 | $1608 |
| &nbsp;&nbsp;&nbsp;&nbsp;United Kingdom  | 70 | 76 |
| &nbsp;&nbsp;&nbsp;&nbsp;Rest of world  | 433 | 259 |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Total property and equipment, net  | $1986 | $1943 |

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**Item 2. Management's Discussion and Analysis of Financial Condition and Results of Operations.**

*The following discussion and analysis of our financial condition and results of operations should be read in conjunction with our unaudited condensed consolidated financial statements and related notes included elsewhere in this Quarterly Report, and our audited consolidated financial statements and related notes for the year ended December 31, 2025 included in the Annual Report. Some of the information contained in this discussion and analysis or set forth elsewhere in this Quarterly Report, including information with respect to our plans and strategy for our business, includes forward-looking statements that involve risks and uncertainties. As a result of many factors, including those factors set forth in the risks identified in Part I, Item 1A of the Annual Report, as updated by any information appearing in Part II, Item 1A of any of our subsequent Quarterly Reports on Form 10-Q, and our other filings with the Securities and Exchange Commission (the "SEC") our actual results could differ materially from the results, performance or achievements expressed in or implied by these forward-looking statements.*

**Overview** 

We are a biopharmaceutical company developing and commercializing novel therapies for diseases with unmet need, with a focus on cardiovascular indications. Our portfolio of assets is based on strong biologic rationale or validated mechanisms and offers the potential for differentiation.

ARCALYST is an interleukin-1α ("IL-1α") and interleukin-1β ("IL-1β") cytokine trap. In 2017, we licensed ARCALYST from Regeneron, which discovered and initially developed the drug. Our exclusive license to ARCALYST from Regeneron includes worldwide rights, excluding the Middle East and North Africa, for all applications other than those in oncology and local administration to the eye or ear. We received FDA approval of ARCALYST for the treatment of recurrent pericarditis and reduction in risk of recurrence in adults and children 12 years and older in March 2021. Recurrent pericarditis is a painful inflammatory cardiovascular disease with an estimated United States prevalent population of approximately 40,000 patients seeking and receiving medical treatment. ARCALYST is also approved in the United States for the treatment of Cryopyrin-Associated Periodic Syndromes ("CAPS"), including Familial Cold Autoinflammatory Syndrome and Muckle-Wells Syndrome in adults and children 12 years and older, and the maintenance of remission in Deficiency of Interleukin-1 Receptor Antagonist ("DIRA") in adults and children weighing 10 kg or more. ARCALYST is commercially available across the United States through a select network of specialty pharmacies. We are responsible for sales and distribution of ARCALYST in all approved indications in the United States, and evenly split profits on sales, as well as third party proceeds, with Regeneron. In 2022, we granted Hangzhou Zhongmei Huadong Pharmaceutical Co., Ltd. ("Huadong") exclusive rights to develop and commercialize ARCALYST in the Huadong Territory (as defined below). In 2023, Regeneron initiated a technology transfer of the manufacturing process for ARCALYST drug substance. Since then we have worked to qualify Samsung Biologics Co., Ltd. ("Samsung") as our replacement contract development and manufacturing organization ("CDMO") and, in April 2026, the FDA accepted the supplemental biologics license application related to such technology transfer and assigned a Prescription Drug User Fee Act target action date of June 19, 2026. In December 2024, we initiated a collaborative study agreement with The Mayo Clinic (together with Johns Hopkins University) to investigate the effects of ARCALYST in the treatment of cardiac sarcoidosis.

KPL-387 is an investigational, fully human immunoglobulin G2 monoclonal antibody that binds human interleukin-1 receptor 1 ("IL-1R1"), inhibiting IL-1α- and IL-1β-mediated signaling. KPL-387 is an independently developed asset that we believe may expand the recurrent pericarditis market and provide an additional treatment option for patients, with the potential to add the convenience of monthly subcutaneous self-administration with a liquid formulation. In July 2025, we announced that the Phase 2 dose-focusing portion of the Phase 2/3 clinical trial of KPL-387 in recurrent pericarditis had begun recruiting. We expect data from the Phase 2 portion of the trial in the second half of 2026 and plan to use the totality of the data to determine further development strategy. In September 2025, we announced plans to conduct a supplemental Phase 2 transition to KPL-387 monotherapy dosing and administration study to evaluate the efficacy and safety of dosing regimens used to transition patients from standard therapies to KPL-387 monotherapy. In April 2026, we announced our expectation to initiate a pivotal Phase 3 clinical trial of KPL-387 in recurrent pericarditis by the end of 2026. In October 2025, the FDA granted Orphan Drug Designation to KPL-387 for the treatment of pericarditis.

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KPL-1161 is an independently developed, pre-clinical, Fc-modified immunoglobulin G2 monoclonal antibody that binds IL-1R1, inhibiting IL-1α- and IL-1β-mediated signaling. KPL-1161 is a modified version of KPL-387 designed to have an increased drug half-life that we believe could support quarterly subcutaneous dosing. We are currently conducting preclinical activities with respect to this asset, and expect to initiate a Phase 1 first-in-human clinical trial by the end of 2026.

Abiprubart is an investigational monoclonal antibody inhibitor of CD40-CD154 costimulatory interaction, which we believe to be an attractive approach to address multiple autoimmune disease pathologies. We hold an exclusive worldwide license to abiprubart from Beth Israel Deaconess Medical Center, Inc. ("BIDMC"). In February 2025, we announced our plans to discontinue development of abiprubart in Sjogren's Disease and to explore strategic alternatives for the asset.

**Components of Our Results of Operations**

***Product revenue, net***

We have been generating product revenue from sales of ARCALYST since April 2021. ARCALYST is sold through a third-party logistics provider that distributes primarily through a select network of specialty pharmacies (collectively, "customers"), which deliver the medication to patients by mail. ARCALYST is currently only approved for sale in the United States, and, therefore, we expect to derive substantially all of our product revenue from the United States for the foreseeable future.

Net revenue from product sales is recognized at the transaction price when the customer obtains control of our product, which occurs at a point in time, typically upon shipment of the product from the third-party logistics provider.

Our net revenues represent total revenues adjusted for discounts and allowances, including estimated cash discounts, chargebacks, rebates, returns, copay assistance, and specialty pharmacy and distributor fees. These adjustments represent variable consideration under ASC 606 and are estimated using the expected value method and are recorded when revenue is recognized on the sale of the product. These adjustments are established by management as its best estimate based on available information and will be adjusted to reflect known changes in the factors that impact such allowances. Adjustments for variable consideration are determined based on the contractual terms with customers, historical trends, communications with customers and the levels of inventory remaining in the distribution channel, as well as expectations about the market for the product and anticipated introduction of competitive products.

***License and collaboration revenue***

License and collaboration revenue includes amounts recognized related to upfront payments, royalty revenue, milestone payments and products sold under collaboration agreements.

In February 2022, we entered into a collaboration and license agreement (the "Huadong Collaboration Agreement"), with Huadong, pursuant to which we granted Huadong exclusive rights to develop and commercialize ARCALYST in a specified territory, which currently includes the following countries: People's Republic of China, Hong Kong SAR, Macao SAR, Taiwan Region, Indonesia, The Philippines, Thailand, Bangladesh, Bhutan, Brunei, Burma, Cambodia, India, Laos, Malaysia, Maldives, Mongolia, Nepal, New Zealand, Sri Lanka, and Vietnam (collectively, the "Huadong Territory").

Under the Huadong Collaboration Agreement, we received a total upfront cash payment of $12.0 million for the Huadong Territory license of ARCALYST. In the fourth quarter of 2024, following the achievement of a regulatory milestone under the Huadong Collaboration Agreement, Huadong became obligated to make an additional cash payment of $20.0 million, which was received in the first quarter of 2025. In addition, we will be eligible to receive additional contingent sales-based milestones payments related to ARCALYST. Huadong will also be obligated to pay us tiered percentage royalties on ARCALYST ranging from the low-to-mid teens on annual net sales in the Huadong Territory, subject to certain reductions tied to ARCALYST manufacturing costs and certain other customary reductions, with an aggregate minimum floor. Royalties will be payable on a country-by-country or region-by-region basis until the later of

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(i) 12 years after the first commercial sale of ARCALYST in such country or region in the Huadong Territory, (ii) the date of expiration of the last valid patent claim of our patent rights or any joint collaboration patent rights that covers ARCALYST in such country or region in the Huadong Territory, and (iii) the expiration of the last regulatory exclusivity for ARCALYST in such country or region in the Huadong Territory. We have recognized $0.2 million of revenue of the $32.0 million transaction price under the Huadong Collaboration Agreement as of March 31, 2026, and will recognize the remaining revenue as materials are shipped.

In the third quarter of 2022, we entered into a license agreement (the "Genentech License Agreement") with Genentech, pursuant to which we granted Genentech exclusive worldwide rights to develop and commercialize vixarelimab and related antibodies (each, a "Genentech Licensed Product").

Under the Genentech License Agreement, we will be eligible to receive up to a total of approximately $600.0 million in contingent payments, including specified development, regulatory and sales-based milestones, of which approximately $570.0 million remains as of March 31, 2026. We will also be eligible to receive tiered percentage royalties on a Genentech Licensed Product-by-Genentech Licensed Product basis ranging from low-double digits to mid-teens on annual net sales of each Genentech Licensed Product, subject to certain customary reductions, with an aggregate minimum floor, before fulfilling our upstream financial obligations. Royalties will be payable on a Genentech Licensed Product-by-Genentech Licensed Product and country-by-country basis until the latest to occur of the expiration of certain patents that cover a Genentech Licensed Product, the expiration of regulatory exclusivity for such Genentech Licensed Product, or the tenth anniversary of first commercial sale of such Genentech Licensed Product in such country.

***Operating expenses***

*Cost of goods sold*

Cost of goods sold includes production and distribution costs of ARCALYST, amortization of the $20.0 million payment we made to Regeneron in the first quarter of 2021 upon achievement of a regulatory milestone and other miscellaneous product costs associated with ARCALYST. Cost of goods sold also includes labor and overhead costs associated with the production of ARCALYST associated with supply chain, quality, and regulatory activities, and the technology transfer of the manufacturing process for ARCALYST.

*Collaboration expenses*

Collaboration expenses consist of Regeneron's share of the profit related to ARCALYST sales under the Regeneron Agreement and the cost of products sold under collaboration agreements. We evenly split profits on sales of ARCALYST with Regeneron, where profits are determined after deducting from net sales of ARCALYST certain costs related to the manufacturing and commercialization of ARCALYST. Such costs include but are not limited to (i) our cost of goods sold for product used, sold or otherwise distributed for patient use by us; (ii) customary commercialization expenses, including the cost of our field force, and (iii) our cost to market, advertise and otherwise promote ARCALYST, with such costs identified in subsection (iii) subject to specified limits. With respect to the technology transfer of ARCALYST drug substance manufacturing initiated by Regeneron in March 2023, to the extent permitted by the Regeneron Agreement, the fully-burdened costs of each of us and Regeneron incurred in performing such technology transfer shall also be deducted from net sales of ARCALYST to determine profit. We also evenly split with Regeneron any proceeds received by us from any licensees, sublicensees and distributors in consideration for the sale, license or other disposition of rights with respect to ARCALYST, including upfront payments, milestone payments and royalties.

*Research and development expenses*

Research and development expenses consist primarily of costs incurred in connection with the research and development of our product candidates. We expense research and development costs as incurred. These expenses may include:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;●expenses incurred to conduct the necessary preclinical studies and clinical trials required to obtain regulatory approval;

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&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;●expenses incurred under agreements with contract research organizations ("CROs") that are primarily engaged in the oversight and conduct of our clinical trials and CDMOs that are primarily engaged to provide preclinical and clinical drug substance and product for our research and development programs for our product candidates;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;●other costs related to acquiring and manufacturing preclinical and clinical trial materials, including manufacturing validation batches, as well as investigative sites and consultants that conduct our clinical trials, preclinical studies and other scientific development services;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;●payments made in cash or equity securities under third party licensing, acquisition and other similar agreements;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;●employee-related expenses, including salaries and benefits, travel and share-based compensation expense for employees engaged in research and development functions;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;●costs related to compliance with regulatory requirements; and

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;●allocated facilities-related costs, which include rent and utilities, depreciation and other expenses.

We recognize external development costs based on an evaluation of the progress to completion of specific tasks using information provided to us by our service providers. This process involves reviewing open contracts and purchase orders, communicating with our personnel to identify services that have been performed on our behalf and estimating the level of service performed and the associated cost incurred for the service when we have not yet been invoiced or otherwise notified of actual costs. Nonrefundable advance payments for goods or services to be received in the future for use in research and development activities are recorded as prepaid expenses. Such amounts are recognized as an expense as the goods are delivered or the related services are performed, or until it is no longer expected that the goods will be delivered or the services rendered.

Our direct research and development expenses are tracked on a program-by-program basis for our product candidates and consist primarily of external costs, such as fees paid to outside consultants, CROs, CDMOs and research laboratories in connection with our preclinical development, process development, manufacturing and clinical development activities. Our direct research and development expenses by program also include fees incurred under license, acquisition and other similar agreements. We do not allocate employee costs or facility expenses, including depreciation or other indirect costs, to specific programs because these costs are deployed across multiple programs and, as such, are not separately classified. We use internal resources primarily to conduct our research and discovery activities as well as for managing our preclinical and clinical development, process development and manufacturing clinical and preclinical materials.

Research and development activities are central to our business. Product candidates in later stages of clinical development generally have higher costs than those in earlier stages of clinical development, primarily due to the increased size and duration of later-stage clinical trials. As a result, we expect that our research and development expenses will be substantial over the next several years as we conduct our ongoing and/or planned clinical trials for our product candidates, as well as conduct other preclinical and clinical development, and make regulatory filings for our product candidates.

At this time, we cannot reasonably estimate or know the nature, timing and costs of the efforts that will be necessary to complete the clinical development of our current or future product candidates or when, if ever, we will realize revenue from the sale of our current or future product candidates.

*Selling, general and administrative expenses*

Selling, general and administrative expenses consist primarily of salaries and benefits, including share based compensation expense for personnel in selling, marketing, medical, executive, business development, finance, human

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resources, legal and support personnel functions. Selling, general and administrative expenses also include external commercialization, marketing, and professional fees for legal, patent, and accounting services.

We expect that our selling, general and administrative expenses will continue to increase in the future as we continue to expand our infrastructure related to the commercialization of ARCALYST and our other product candidates, if approved.

***Other income, net***

Other income, net consists of interest income recognized from investments in money market funds, United States Treasury Securities and other miscellaneous income offset by expenses related to investments.

***Income taxes***

Our income is subject to the enacted United Kingdom statutory corporate tax rate. Our wholly owned United States subsidiaries, including Kiniksa Pharmaceuticals, Inc. ("Kiniksa US"), are subject to federal and state income taxes in the United States. Our wholly owned subsidiary Kiniksa Pharmaceuticals (UK), Ltd. ("Kiniksa UK"), its Swiss branch office, and Kiniksa UK's wholly owned subsidiaries, including Kiniksa Pharmaceuticals, GmbH ("Kiniksa Switzerland") are subject to taxation in their respective countries.

On July 4, 2025, new U.S tax legislation was signed into law (known as the "One Big Beautiful Bill Act" or "OBBBA") which makes permanent many of the tax provisions enacted in 2017 as part of the Tax Cuts and Jobs Act that were set to expire at the end of 2025. The tax provisions of the legislation did not have a material impact on our operations.

**Results of Operations** 

***Comparison of the Three Months Ended March 31, 2026 and 2025***

The following table summarizes our results of operations for the three months ended March 31, 2026 and 2025:

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| | | | |
|:---|:---|:---|:---|
|  | **Three Months Ended**  | **Three Months Ended**  | |
|  | **March 31,**  | **March 31,**  | |
|  | **2026** | **2025** | <br>**Change** |
|  | **(in thousands)** | **(in thousands)** | **(in thousands)** |
| Revenue: |  |  |  |
| &nbsp;&nbsp;Product revenue, net | $214266 | $137785 | $76481 |
| &nbsp;&nbsp;License and collaboration revenue |  |  |  |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Total revenue | 214266 | 137785 | 76481 |
| Costs and Operating expenses: |  |  |  |
| &nbsp;&nbsp;Cost of goods sold | 20796 | 17868 | 2928 |
| &nbsp;&nbsp;Collaboration expenses | 75577 | 43790 | 31787 |
| &nbsp;&nbsp;Research and development | 27475 | 19325 | 8150 |
| &nbsp;&nbsp;Selling, general and administrative | 61151 | 43530 | 17621 |
| &nbsp;&nbsp;&nbsp;&nbsp;Total operating expenses | 184999 | 124513 | 60486 |
| Income from operations | 29267 | 13272 | 15995 |
| Other income, net | 3414 | 2293 | 1121 |
| Income before income taxes | 32681 | 15565 | 17116 |
| Provision for income taxes | (10089) | (7026) | (3063) |
| Net income | $22592 | $8539 | $14053 |

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*Product revenue, net*

We recognized net revenue from the sale of ARCALYST of $214.3 million for the three months ended March 31, 2026, compared to $137.8 million for the three months ended March 31, 2025, an increase of $76.5 million. The increase in product revenue was driven primarily by an increase in patient enrollment.

*Cost of goods sold*

We recognized cost of goods sold of $20.8 million for the three months ended March 31, 2026, compared to $17.9 million for the three months ended March 31, 2025, an increase of $2.9 million. The increase in cost of goods sold relates primarily to the increase in sales of ARCALYST offset by favorable production variances.

*Collaboration expenses* 

Collaboration expenses were $75.6 million for the three months ended March 31, 2026, compared to $43.8 million for the three months ended March 31, 2025, an increase of $31.8 million. The increase of $31.8 million relates primarily to increased revenue from sales of ARCALYST.

*Research and development expenses*

---

| | | | |
|:---|:---|:---|:---|
|  | **Three Months Ended**  | **Three Months Ended**  | |
|  | **March 31,**  | **March 31,**  | |
|  | **2026** | **2025** | <br>**Change** |
|  | **(in thousands)** | **(in thousands)** | **(in thousands)** |
| Direct research and development expenses by program: |  |  |  |
| &nbsp;&nbsp;ARCALYST | $341 | $355 | $(14) |
| &nbsp;&nbsp;KPL-387 | 16152 | 5178 | 10974 |
| &nbsp;&nbsp;KPL-1161 | 955 | 100 | 855 |
| &nbsp;&nbsp;Abiprubart | 53 | 4367 | (4314) |
| Unallocated research and development expenses: |  |  |  |
| &nbsp;&nbsp;&nbsp;&nbsp;Personnel related (including share-based compensation) | 5933 | 5923 | 10 |
| &nbsp;&nbsp;&nbsp;&nbsp;Other | 4041 | 3402 | 639 |
| &nbsp;&nbsp;Total research and development expenses | $27475 | $19325 | $8150 |

---

Research and development expenses were $27.5 million for the three months ended March 31, 2026, compared to $19.3 million for the three months ended March 31, 2025, an increase of $8.2 million.

Direct costs for our KPL-387 program were $16.2 million during the three months ended March 31, 2026, compared to $5.2 million during the three months ended March 31, 2025. The increase in expenses incurred primarily related to the enrollment and continuation of our Phase 2/3 clinical trial in recurrent pericarditis during the three months ended March 31, 2026, as compared to the Phase 1 clinical trial in normal healthy volunteers during the three months ended March 31, 2025.

Direct costs for our KPL-1161 program were $1.0 million for the three months ended March 31, 2026, compared to $0.1 million during the three months ended March 31, 2025. For the three months ended March 31, 2026 and 2025, expenses incurred primarily related to pre-clinical development.

The direct costs for our abiprubart program were $0.1 million during the three months ended March 31, 2026, compared to $4.4 million during the three months ended March 31, 2025, a decrease of $4.3 million. For the three months ended March 31, 2025, expenses incurred primarily related to the close-out of our Phase 2b clinical trial in Sjögren's Disease and $2.5 million of termination expenses associated with cancelled manufacturing agreements.

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Unallocated research and development expenses were $10.0 million and $9.3 million for the three months ended March 31, 2026 and March 31, 2025, respectively. Personnel-related costs for the three months ended March 31, 2026 and 2025 included share-based compensation of $1.6 million and $1.2 million, respectively.

*Selling, general and administrative expenses*

Selling, general and administrative expenses were $61.2 million for the three months ended March 31, 2026, compared to $43.5 million for the three months ended March 31, 2025. The increase of $17.6 million was primarily due to an increase of $10.8 million in personnel-related costs largely attributable to an increase in headcount and an increase in sales and marketing expenses of $5.2 million largely attributable to increased promotional activities and the timing of free goods designation. Personnel-related costs for the three months ended March 31, 2026 and 2025 included share-based compensation of $7.9 million and $5.8 million, respectively.

*Other income, net*

Other income, net was $3.4 million and $2.3 million for the three months ended March 31, 2026 and March 31, 2025, respectively. The year-over-year increase was driven primarily by higher interest income generated by increased average holdings of cash, cash equivalents, and short-term investments.

*Provision for income taxes*

We recorded an income tax provision of $10.1 million and $7.0 million for the three months ended March 31, 2026 and March 31, 2025, respectively. The provision for income taxes was driven primarily by income earned in Switzerland, UK and the United States as well as uncertain tax positions offset in part by tax benefits related to share-based compensation, United States federal and state research and development credits ("R&D Credits") and Foreign Derived Intangible Income ("FDII") deduction.

**Liquidity and Capital Resources**

As of March 31, 2026, our principal source of liquidity was cash, cash equivalents and short-term investments, which totaled $468.1 million. Net income was $22.6 million and $8.5 million for the three months ended March 31, 2026 and 2025, respectively. We expect our cash balance and our expected cash inflows from operations to allow us to meet our current operating plan.

Under various agreements with third parties, we have agreed to make milestone payments, pay royalties, pay annual maintenance fees and to meet due diligence requirements, each based upon specified events. Pursuant to the Regeneron Agreement, we have entered into a supply agreement with Regeneron to purchase both clinical and commercial product. We have entered into lease agreements for office and laboratory space, and vehicles, with total future lease payments of $9.9 million, $3.6 million of which are due within one year. In connection with our ongoing technology transfer of ARCALYST drug substance manufacturing, we have entered into a Master Services Agreement and a Product Specific Agreement with Samsung. Our commitments under such agreements, which includes the purchase of raw materials and related service fees, obligates us to minimum payments of $147.1 million, $59.8 million of which are due within one year. As of March 31, 2026, we have capitalized $21.1 million of production cost into inventory as semi-finished goods related to drug substance manufactured at Samsung. We have additionally entered into agreements with several CDMOs to provide us with preclinical and clinical trial materials for our non-ARCALYST assets, which obligate us to minimum payments of $10.2 million all of which are due within one year. We have long-term incentive plans for our employees that may result in cash award payments of $23.1 million, based upon the achievement of certain regulatory milestones, none of which are expected to be achieved in the next year.

Under various agreements with third parties, we are entitled to receive upfront payments, milestone payments, and royalties, each based upon specified milestones. In 2025, we received a $20.0 million milestone payment related to Huadong's achievement of a regulatory milestone under the Huadong Collaboration Agreement, $10.0 million of which was paid to Regeneron in 2025 as part of the Regeneron Agreement.

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These agreements impact our short-term and long-term liquidity and capital needs.

***Cash Flows***

The following table summarizes our cash flows for each of the periods presented:

---

| | | |
|:---|:---|:---|
|  | **Three Months Ended**  | **Three Months Ended**  |
|  | **March 31,**  | **March 31,**  |
|  | **2026** | **2025** |
|  | **(in thousands)** | **(in thousands)** |
| Net cash provided by operating activities | $50199 | $22324 |
| Net cash used in investing activities | (31916) | (51541) |
| Net cash provided by financing activities | 6073 | 2768 |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Net increase (decrease) in cash and cash equivalents | $24356 | $(26449) |

---

*Operating Activities* 

Net cash provided by operations was $50.2 million and $22.3 million for the three months ended March 31, 2026 and 2025, respectively. The increase in cash provided by operating activities is primarily due to an increase in net contribution from higher ARCALYST sales offset by a decrease in net cash received from licensing agreements of $20.0 million.

*Investing Activities*

Net cash used in investing activities was $31.9 million and $51.5 million for the three months ended March 31, 2026 and 2025, respectively. The increase in net cash used in investing activities was driven by managing our cash and short-term investment portfolio mix as we deployed higher levels of cash into Treasury Securities with longer-terms.

*Financing Activities*

During the three months ended March 31, 2026 and 2025, net cash provided by financing activities was $6.1 million and $2.8 million, respectively, consisting of proceeds from the exercise of share options offset by payments in connection with ordinary shares tendered for employee tax obligations.

***Funding Requirements***

We expect to incur significant expenses in connection with our ongoing and planned activities as we continue to commercialize ARCALYST and advance our current and future product candidates through preclinical and clinical development, seek regulatory approval and commercialize one or more of our current or future product candidates, if approved. We may also incur expenses in connection with collaboration, licensing or other strategic transactions. Further, we may incur expenses related to milestone, royalty and other payments payable to third parties with whom we have entered into license, acquisition and other similar agreements to acquire the rights to our product candidates 

We believe that our existing cash, cash equivalents and short-term investments will enable us to fund our operating expenses and capital expenditure requirements for at least the next 12 months. The future viability of our company is dependent on our ability to fund our operations through sales of ARCALYST and/or raise additional capital, such as through debt or equity offerings, as needed. We anticipate that we may require additional capital if we choose to pursue collaboration, licensing or other strategic transactions. We expect to continue to incur significant expenses related to product manufacturing, including technology transfer costs, sales, marketing and distribution of ARCALYST. In addition, if we obtain regulatory approval for any of our current or future product candidates, pursue additional indications or additional territories for our products or any of our current or future product candidates, we expect to incur significant expenses related to product development and manufacturing, sales, marketing and distribution, depending on where we choose to commercialize.

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Because of the numerous risks and uncertainties associated with research, development and commercialization of biologic products, we are unable to estimate the exact amount of our working capital requirements. Our future funding requirements may be impacted by a number of factors, including those described in Part I, Item 1A of the Annual Report, as updated by any information appearing in Part II, Item 1A of any of our subsequent Quarterly Reports on Form 10-Q.

**Critical Accounting Policies and Significant Judgments and Estimates**

Our condensed consolidated financial statements are prepared in accordance with generally accepted accounting principles in the United States. The preparation of our condensed consolidated financial statements and related disclosures requires us to make estimates and judgments that affect the reported amounts of assets, liabilities, revenue, costs and expenses, and the disclosure of contingent assets and liabilities in our financial statements. We base our estimates on historical experience, known trends and events and various other factors that we believe are reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. We evaluate our estimates and assumptions on an ongoing basis. Our actual results may differ from these estimates under different assumptions or conditions.

Our critical accounting policies are described under the heading "Management's Discussion and Analysis of Financial Condition and Results of Operations—Critical Accounting Policies and Significant Judgments and Estimates" in the Annual Report and the notes to the consolidated financial statements included in Item 1, "Financial Statements (Unaudited)" included in this Quarterly Report. We believe that of our critical accounting policies, the following accounting policies involve the most judgment and complexity:

● revenue recognition

● accrued research and development expenses

● uncertain tax positions; and

● realizability of deferred tax assets.

**Item 3.** **Quantitative and Qualitative Disclosures About Market Risk.**

***Interest Rate Risk***

We are exposed to market risks in the ordinary course of our business. These risks primarily include interest rate sensitivities related to our short-term investments. There were no material changes to our quantitative and qualitative disclosures about market risk related to our investment activities during the three months ended March 31, 2026 as disclosed in "Item 7A. Quantitative and Qualitative Disclosures About Market Risks" of the Annual Report.

**Item 4.** **Controls and Procedures.**

***Limitations on Effectiveness of Controls and Procedures***

In designing and evaluating our disclosure controls and procedures, management recognizes that any controls and procedures, no matter how well designed and operated, can provide only reasonable assurance of achieving the desired control objectives.

***Evaluation of Disclosure Controls and Procedures***

Our management, with the participation of our principal executive officer and principal financial officer, evaluated, as of the end of the period covered by this Quarterly Report, the effectiveness of our 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

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"Exchange Act")). Based on that evaluation, our principal executive officer and principal financial officer concluded that our disclosure controls and procedures were effective at the reasonable assurance level as of March 31, 2026.

***Changes in Internal Control over Financial Reporting***

There was no change in our internal control over financial reporting (as defined in Rules 13a-15(f) and 15d-15(f) under the Exchange Act) during the three months ended March 31, 2026 that has materially affected, or is reasonably likely to materially affect, our internal control over financial reporting.

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**PART II - OTHER INFORMATION**

**Item 1.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Legal Proceedings.**

We are not party to any material legal proceedings.

**Item 1A.** **Risk Factors.** 

In addition to the information discussed elsewhere in this Quarterly Report, you should carefully review and consider the risk factors disclosed in Part I, Item 1A of the Annual Report, as updated by any information appearing in Part II, Item 1A of any of our subsequent Quarterly Reports on Form 10-Q. These risks could materially and adversely affect our business, results of operations, financial condition and prospects. The risks and uncertainties described therein are not the only ones we face. Additional risks and uncertainties not currently known to us or that we deem immaterial also may impair our business operations.

**Item 2. Unregistered Sales of Equity Securities, Use of Proceeds and Issuer Purchases of Equity Securities**

None.

**Item 3. Defaults Upon Senior Securities.**

None.

**Item 4. Mine Safety Disclosures.**

None.

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**Item 5. Other Information.**

**Trading Arrangements**

During the fiscal quarter ended March 31, 2026, none of our directors or officers (as defined in Rule 16a-1(f) under the Exchange Act) adopted or terminated a "Rule 10b5-1 trading arrangement" or a "non-Rule 10b5-1 trading arrangement" as such terms are defined under Item 408 of Regulation S-K.

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**Item 6. Exhibits**

---

| | | |
|:---|:---|:---|
| | | **Incorporated by Reference** |
| <br>**Exhibit**<br>**Number** | <br>**Exhibit Description** | **Filed/**<br>**Furnished**<br>**Herewith** |
| 10.1 | [Non-Employee Director Compensation Program](knsa-20260331xex10d1.htm) | \* |
| 31.1 | [Rule 13a-14(a) / 15d-14(a) Certification of Chief Executive Officer](knsa-20260331xex31d1.htm) | \* |
| 31.2 | [Rule 13a-14(a) / 15d-14(a) Certification of Chief Financial Officer](knsa-20260331xex31d2.htm) | \* |
| 32.1 | [Section 1350 Certification of Chief Executive Officer](knsa-20260331xex32d1.htm) | \*\* |
| 32.2 | [Section 1350 Certification of Chief Financial Officer](knsa-20260331xex32d2.htm) | \*\* |
| 101.INS | XBRL Instance Document – the instance document does not appear in the Interactive Data File because its XBRL tags are embedded within the Inline XBRL document | \*\*\* |
| 101.SCH | Inline XBRL Taxonomy Extension Schema Document | \*\*\* |
| 101.CAL | Inline XBRL Taxonomy Extension Calculation Linkbase Document | \*\*\* |
| 101.DEF | Inline XBRL Extension Definition Linkbase Document | \*\*\* |
| 101.LAB | Inline XBRL Taxonomy Label Linkbase Document | \*\*\* |
| 101.PRE | Inline XBRL Taxonomy Extension Presentation Linkbase Document | \*\*\* |
| 104 | Cover page Interactive Data File (formatted in Inline XBRL and contained in Exhibit 101) - The cover page interactive data file does not appear in the Interactive Data File because its XBRL tags are embedded within the Inline XBRL document | \*\*\* |

---

\* Filed herewith

\*\* Furnished herewith

\*\*\* Submitted electronically herewith

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**SIGNATURES**

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

---

| | | |
|:---|:---|:---|
|  | **KINIKSA PHARMACEUTICALS INTERNATIONAL, PLC** | **KINIKSA PHARMACEUTICALS INTERNATIONAL, PLC** |
| Date: April 28, 2026 | By: | /s/ Mark Ragosa |
|  |  | Mark Ragosa |
|  |  | Executive Vice President and Chief Financial Officer<br>(Principal Financial Officer) |

---

## Exhibit 10.1

Exhibit 10.1

**Kiniksa Pharmaceuticals International, plc.**

**Non-Employee Director Compensation Program**

Non-employee members of the board of directors (the "***Board***") of Kiniksa Pharmaceuticals International, plc (the "***Company***") shall receive cash and equity compensation as set forth in this Non-Employee Director Compensation Program (as amended, this "***Program***"). The cash and equity compensation described in this Program shall be paid or be made, as applicable, automatically and without further action of the Board, to each member of the Board who is not an employee of the Company or any parent or subsidiary of the Company (each, a "***Non-Employee Director***") who is entitled to receive such cash or equity compensation, unless such Non-Employee Director declines the receipt of such cash or equity compensation by written notice to the Company. This Program shall remain in effect until it is revised or rescinded by further action of the Board. This Program may be amended, modified or terminated by the Board at any time in its sole discretion. The terms and conditions of this Program shall supersede any prior cash and/or equity compensation arrangements for service as a member of the Board between the Company and any of its Non-Employee Directors. No Employee Director shall have any rights hereunder.

**I.** **Cash Compensation**

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;A.<u>Annual Retainers</u>. Each Non-Employee Director shall receive an annual retainer of $50,000 for service on the Board.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;B. <u>Additional Annual Retainers</u>. In addition, each Non-Employee Director shall receive the following annual retainers:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1. *Chairperson of the Board or Lead Independent Director*. A Non-Employee Director serving as Chairperson of the Board or Lead Independent Director shall receive an additional annual retainer of $30,000 for such service.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;2. *Audit Committee*. A Non-Employee Director serving as Chairperson of the Audit Committee shall receive an additional annual retainer of $20,000 for such service. A Non-Employee Director serving as a member other than the Chairperson of the Audit Committee shall receive an additional annual retainer of $10,000 for such service.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;3.*Compensation Committee*. A Non-Employee Director serving as Chairperson of the Compensation Committee shall receive an additional annual retainer of $20,000 for such service. A Non-Employee Director serving as a member other than the Chairperson of the Compensation Committee shall receive an additional annual retainer of $9,000 for such service.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;4. *Nominating and Corporate Governance Committee*. A Non-Employee Director serving as Chairperson of the Nominating and Corporate Governance Committee shall receive an additional annual retainer of $10,000 for such service. A Non-Employee Director serving as a member other than the Chairperson of the Nominating and Corporate Governance Committee shall receive an additional annual retainer of $5,000 for such service.

------

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;5.*Science and Research Committee*. A Non-Employee Director serving as Chairperson of the Science and Research Committee shall receive an additional annual retainer of $20,000 for such service. A Non-Employee Director serving as a member other than the Chairperson of the Science and Research Committee shall receive an additional annual retainer of $9,000 for such service.

C.<u>Payment of Retainers</u>. The annual retainers described in Sections I(A) and I(B) shall be earned on a quarterly basis based on a calendar quarter and shall be paid in cash by the Company in arrears not later than the fifteenth day following the end of each calendar quarter. In the event a Non-Employee Director does not serve as a Non-Employee Director, or in the applicable positions described in Section I(B), for an entire calendar quarter, the retainer paid to such Non-Employee Director shall be prorated for the portion of such calendar quarter actually served as a Non-Employee Director, or in such position, as applicable.

**II.** **Equity Compensation** 

Non-Employee Directors shall be granted the equity awards described below. The awards described below shall be granted under and shall be subject to the terms and provisions of the Company's 2018 Incentive Award Plan or any other applicable Company equity incentive plan then-maintained by the Company (the "***Equity Plan***") and shall be granted subject to award agreements in substantially the form previously approved by the Board. All applicable terms of the Equity Plan apply to this Program as if fully set forth herein, and all grants of share options hereby are subject in all respects to the terms of the Equity Plan and the applicable award agreement.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;A.<u>Initial Awards</u>. Each Non-Employee Director who is initially elected or appointed to the Board shall automatically be granted a mix of (a) an option to purchase the Company's Class A ordinary shares and (b) restricted stock units, representing the right to receive Class A ordinary shares ("***RSUs***"), with a combined value equal to $700,000 divided by the Black-Scholes Value (as defined below), rounded down to the nearest whole share, with such other adjustments as determined by the Board's Compensation Committee, but no more than a total of 93,300 shares, of the Company's Class A ordinary shares on the date of such initial election or appointment. The proportion of share options to RSUs included in such award shall be determined by the Board's Compensation Committee from time-to-time. The awards described in this Section II(A) shall be referred to as "***Initial Awards***." No Non-Employee Director shall be granted more than one Initial Award.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;B.<u>Subsequent Awards</u>. A Non-Employee Director who (i) has been serving as a Non-Employee Director on the Board for at least six (6) months as of the date of any annual meeting of the Company's shareholders and (ii) will continue to serve as a Non-Employee Director immediately following such meeting, shall be automatically granted a mix of (a) an option to purchase the Company's Class A ordinary shares and (b) RSUs, with a combined value equal to $400,000 divided by the Black-Scholes Value, rounded down to the nearest whole share, with such other adjustments as determined by the Board's Compensation Committee, but no more than a total of 53,600 shares, of the Company's Class A ordinary shares on the date of such annual meeting. The proportion of share options to RSUs included in such award shall be determined by the Board's Compensation Committee from time-to-time. The awards described in this Section

------

II(B) shall be referred to as "***Subsequent Awards***." For the avoidance of doubt, a Non-Employee Director elected for the first time to the Board at an annual meeting of the Company's shareholders shall only receive an Initial Award in connection with such election, and shall not receive any Subsequent Award on the date of such meeting as well.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;C.<u>Black-Scholes Value</u>. For purposes of this Section II, "***Black-Scholes Value***" means the per share fair value of an option calculated on the basis of the Black-Scholes option pricing model and using as inputs to such model (i) for the value of one Class A ordinary share of the Company, the average closing price of the Company's Class A ordinary shares over each trading day occurring in the 30 calendar days ending on the last day of the month prior to the month in which the grant date of the relevant Initial Award or Subsequent Award occurs and (ii) such other assumptions as are determined by the Company's Chief Accounting Officer on or prior to the grant date of the relevant Initial Award or Subsequent Award.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;D.<u>Termination of Employment of Employee Directors</u>. Members of the Board who are employees of the Company or any parent or subsidiary of the Company who subsequently terminate their employment with the Company and any parent or subsidiary of the Company and remain on the Board will not receive an Initial Award pursuant to Section II(A) above, but to the extent that they are otherwise entitled, will receive, after termination of employment with the Company and any parent or subsidiary of the Company, Subsequent Awards as described in Section II(B) above.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E.<u>Terms of Option Awards Granted to Non-Employee Directors</u>

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1. *Exercise Price*. The per share exercise price of each option granted to a Non-Employee Director shall equal the Fair Market Value (as defined in the Equity Plan) of a share of the Company's Class A ordinary shares on the date the option is granted.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;2.*Vesting*. The share options contained in an Initial Award shall vest and become exercisable as to one-third of the share options subject to the Initial Award on the first anniversary of the date of grant and as to the remainder in twenty-four (24) substantially equal monthly installments thereafter, such that the share options contained in an Initial Award shall be fully vested on the third anniversary of the date of grant, subject to the Non-Employee Director continuing in service as a Non-Employee Director through each such vesting date. The share options contained in a Subsequent Award shall vest and become exercisable in twelve (12) substantially equal monthly installments following the date of grant, with the final installment(s) vesting upon the earlier of (a) the first anniversary following the date of grant or (b) the date of the annual meeting of the Company's shareholders in the following year, in each case, subject to the Non-Employee Director continuing in service on the Board as a Non-Employee Director through each such vesting date. Unless the Board otherwise determines, any share options contained in an Initial Award or Subsequent Award which are unvested or unexercisable at the time of a Non-Employee Director's termination of service on the Board as a Non-Employee Director shall be immediately forfeited upon such termination of service and shall not thereafter become vested and exercisable. All of the share options contained in a Non-Employee Director's Initial Awards and Subsequent Awards shall vest in full immediately prior to the occurrence of a Change in Control (as defined in the Equity Plan), to the extent outstanding at such time.

------

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;3.*Term*. The maximum term of each share option granted to a Non-Employee Director hereunder shall be ten (10) years from the date the option is granted.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;F.<u>Terms of RSU Awards Granted to Non-Employee Directors</u>

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1.*Vesting*. The RSUs contained in an Initial Award shall vest as to one-third of the RSUs subject to the Initial Award on each anniversary of the date of grant, such that the RSUs contained in an Initial Award shall be fully vested on the third anniversary of the date of grant, subject to the Non-Employee Director continuing in service as a Non-Employee Director through each such vesting date. The RSUs contained in a Subsequent Award shall vest in their entirety on the earlier of (a) the first anniversary of the date of grant or (b) the date of the annual meeting of the Company's shareholders in the following year, in each case, subject to the Non-Employee Director continuing in service on the Board as a Non-Employee Director through such vesting date. Unless the Board otherwise determines, any RSUs contained in an Initial Award or Subsequent Award which are unvested at the time of a Non-Employee Director's termination of service on the Board as a Non-Employee Director shall be immediately forfeited upon such termination of service and shall not thereafter become vested. All of the RSUs contained in a Non-Employee Director's Initial Awards and Subsequent Awards shall vest in full immediately prior to the occurrence of a Change in Control (as defined in the Equity Plan), to the extent outstanding at such time.

\* \* \* \* \*

------

## Exhibit 31.1

**Exhibit 31.1**

**CERTIFICATIONS**

I, Sanj K. Patel, certify that:

1. I have reviewed this Quarterly Report on Form 10-Q of Kiniksa Pharmaceuticals International, plc;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4. The registrant's other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(c) Evaluated the effectiveness of the registrant's disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(d) Disclosed in this report any change in the registrant's internal control over financial reporting that occurred during the registrant's most recent fiscal quarter (the registrant's fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant's internal control over financial reporting; and

5. The registrant's other certifying officer and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant's auditors and the audit committee of the registrant's board of directors (or persons performing the equivalent functions):

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant's ability to record, process, summarize and report financial information; and

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant's internal control over financial reporting.

---

| | |
|:---|:---|
| April 28, 2026 | /s/ Sanj K. Patel |
|  | Sanj K. Patel |
|  | Chief Executive Officer and Chairman of the Board of Directors<br>(Principal Executive Officer)<br>|

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## Exhibit 31.2

**Exhibit 31.2**

**CERTIFICATIONS**

I, Mark Ragosa, certify that:

1. I have reviewed this Quarterly Report on Form 10-Q of Kiniksa Pharmaceuticals International, plc;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4. The registrant's other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(c) Evaluated the effectiveness of the registrant's disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(d) Disclosed in this report any change in the registrant's internal control over financial reporting that occurred during the registrant's most recent fiscal quarter (the registrant's fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant's internal control over financial reporting; and

5. The registrant's other certifying officer and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant's auditors and the audit committee of the registrant's board of directors (or persons performing the equivalent functions):

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant's ability to record, process, summarize and report financial information; and

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant's internal control over financial reporting.

---

| | |
|:---|:---|
| April 28, 2026 | /s/ Mark Ragosa |
|  | Mark Ragosa |
|  | Chief Financial Officer<br>(Principal Financial Officer) |

---

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## Exhibit 32.1

**Exhibit 32.1**

**CERTIFICATION PURSUANT TO**

**18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO**

**SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002**

I, Sanj K. Patel, Chief Executive Officer and Chairman of the Board of Directors of Kiniksa Pharmaceuticals International, plc (the "Company"), hereby certify, pursuant to 18 U.S.C. §1350, as adopted pursuant to §906 of the Sarbanes-Oxley Act of 2002, that, to the best of my knowledge:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(1) The Quarterly Report on Form 10-Q of the Company for the period ended March 31, 2026 (the "Report") fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended; and

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(2) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

---

| | |
|:---|:---|
| April 28, 2026 | /s/ Sanj K. Patel |
|  | Sanj K. Patel |
|  | Chief Executive Officer and Chairman of the Board of Directors |
|  | (Principal Executive Officer) |

---

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## Exhibit 32.2

**Exhibit 32.2**

**CERTIFICATION PURSUANT TO**

**18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO**

**SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002**

I, Mark Ragosa, Chief Financial Officer of Kiniksa Pharmaceuticals International, plc (the "Company"), hereby certify, pursuant to 18 U.S.C. §1350, as adopted pursuant to §906 of the Sarbanes-Oxley Act of 2002, that, to the best of my knowledge:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(1) The Quarterly Report on Form 10-Q of the Company for the period ended March 31, 2026 (the "Report") fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended; and

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(2) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

---

| | |
|:---|:---|
| April 28, 2026 | /s/ Mark Ragosa |
|  | Mark Ragosa |
|  | Chief Financial Officer<br>(Principal Financial Officer) |

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