Kiniksa Pharmaceuticals International, plc filings document regulatory disclosures for a Nasdaq-listed biopharmaceutical company incorporated in England and Wales. Form 8-K reports cover operating results and financial condition, ARCALYST portfolio execution, investor presentations, and executive appointments or consulting arrangements.
Proxy materials cover annual meeting matters, director elections, executive compensation, shareholder voting procedures, and board governance. The filing record also identifies the company’s Class A ordinary shares, Nasdaq Global Select Market listing, and recurring disclosures tied to its commercial ARCALYST franchise and cardiovascular-focused development portfolio.
Kiniksa Pharmaceuticals International, plc director Cole G. Bradley reported equity compensation transactions. Bradley exercised 2,799 Restricted Share Units that vested in a single installment into the same number of Class A Ordinary Shares, bringing his direct holdings to 15,345 shares. He also received 2,026 new Restricted Share Units that each represent one Class A Ordinary Share, vesting in full on the earlier of the grant anniversary or the next annual shareholder meeting. In addition, he was granted options on 12,158 Class A Ordinary Shares at an exercise price of $48.38 per share, vesting in twelve substantially equal monthly installments and expiring in 2036.
BAKER BROS. ADVISORS LP reported acquisition or exercise transactions in this Form 4 filing.
Kiniksa Pharmaceuticals International, plc reported compensation-related equity grants to directors affiliated with Baker Bros. funds. On May 29, 2026, each of Felix J. Baker, Dr. Stephen R. Biggar and M. Cantey Boyd received 2,026 restricted share units (RSUs) and 12,158 non-qualified share options tied to Class A Ordinary Shares under the 2018 Incentive Award Plan. The RSUs vest on the earlier of May 29, 2027 or the next annual shareholder meeting, subject to continued board service, while the share options have a strike price of $48.38, vest in 12 monthly installments beginning June 29, 2026, and expire on May 28, 2036. The Form 4 attributes indirect pecuniary interests in these awards to 667, L.P. and Baker Brothers Life Sciences LP, with Baker Bros. Advisors LP holding voting and dispositive power, and Julian C. Baker and Felix J. Baker disclaiming beneficial ownership beyond their pecuniary interests.
Kiniksa Pharmaceuticals International, plc held its Annual Meeting of Shareholders on May 29, 2026, where both Class A and higher-vote Class B shares participated. Each Class A share carried one vote, and each Class B share carried ten votes as of the April 6, 2026 record date.
Shareholders re-elected Stephen R. Biggar, G. Bradley Cole and Barry D. Quart as Class II directors to serve until the 2029 Annual Meeting. All director nominees received substantially more votes for than against, with millions of votes in favor and limited opposition or abstentions.
Investors also approved several auditor and compensation items. They confirmed PricewaterhouseCoopers LLP as UK statutory auditors and ratified PwC as US independent registered public accounting firm for the 2026 fiscal year, and authorized the board, through its audit committee, to set PwC’s remuneration.
Shareholders received the UK statutory annual accounts and report for the period ended December 31, 2025 and supported the UK Statutory Directors’ Annual Remuneration Report, the UK Statutory Directors’ Remuneration Policy, and the advisory vote on named executive officer compensation, each passing with strong majorities and relatively low levels of opposition.
Baker Bros. Advisors and related entities filed Amendment No. 6 to their Schedule 13D for Kiniksa Pharmaceuticals International, plc, reporting beneficial ownership of about 7% of Kiniksa’s Class A ordinary shares. Their percentages are based on 46,303,276 Class A shares outstanding as of April 24, 2026.
On May 21, 2026, Kiniksa and the Adviser signed a Deed of Waiver that limits conversions of the Funds’ Class A1 and Class B1 ordinary shares so that the Funds and certain affiliates will not exceed 49.9% of Kiniksa’s outstanding voting rights. Separate 4.99% beneficial ownership limits and 61‑day notice periods apply to conversions of Class A1 and Class B1 shares. Without these conversion limits, the Reporting Persons may be deemed beneficial owners of 32,107,763 Class A ordinary shares, or about 42.5% of the outstanding Class A shares.
Kiniksa Pharmaceuticals International, plc entered into a material definitive agreement with Baker Bros. Advisors LP and affiliated funds. The deed of waiver limits the shareholders’ ability to convert their Class A1 or Class B1 ordinary shares if that conversion would cause them to beneficially own more than 49.9% of Kiniksa’s outstanding voting rights.
The deed can only be amended, waived or terminated with approval from at least 75% of Kiniksa’s outstanding ordinary shares, except when adding additional shareholders to the deed or imposing additional restrictions on the shareholders’ conversion rights.
Kiniksa Pharmaceuticals International ownership update: FMR LLC amended its Schedule 13G to report beneficial ownership of 6,787,700.23 shares of Class A common stock, representing 14.8% of the class. The filing lists sole dispositive power of 6,787,700.23 shares and references a power of attorney and Exhibit 99.
Kiniksa Pharmaceuticals International, plc Chief Medical Officer John F. Paolini reported an exercise-and-sell transaction in Class A Ordinary Shares. On May 1, 2026, he exercised options to acquire 58,424 shares at $10.36 per share and then sold the same number of shares in two open-market transactions at weighted average prices of $53.52 and $54.04. The sales were executed through a broker under a pre-arranged Rule 10b5-1 trading plan. Following the exercise, 29,670 share options remained outstanding and are fully vested, with an expiration date in February 2028.
Kiniksa Pharmaceuticals insider sale notice for Class A Ordinary Shares. The filing reports a broker-facilitated cashless exercise tied to an employee stock option on 05/01/2026 for 58,424 shares. It also reports a prior sale by John F. Paolini of 40,000 shares on 03/02/2026 for $1,792,970.00.
Kiniksa Pharmaceuticals International, plc reported that Chief Strategy Officer Eben Tessari has decided to resign to pursue another executive role in the life sciences industry. He will leave his officer role on May 15, 2026, but will continue supporting the company as a consultant.
Under a new Consulting Agreement effective May 15, 2026, Tessari will advise on strategic and operational matters and serve as a special advisor to the Science and Research Committee through May 15, 2027, with an option to renew. He will be paid $450 per hour, up to 20 hours per month, plus approved expenses. The company states his resignation is not due to any disagreement regarding its operations, policies, or practices.
Kiniksa Pharmaceuticals International, plc Chairman and CEO Sanj K. Patel reported an exercise-and-sale transaction in Class A Ordinary Shares. He exercised share options to acquire 48,565 shares at $30.93 per share and then sold 48,565 shares in an open-market transaction at a weighted-average price of $54.02 per share.
The sale was executed under a pre-arranged Rule 10b5-1 trading plan dated October 31, 2025. Following these direct transactions, his directly held Class A Ordinary Shares were reduced to zero, while separate indirect holdings remain in several family trusts.