Entry into a Material Definitive Agreement. Agreement and Plan of Merger On August 1, 2026, Indivior Pharmaceuticals, Inc., a Delaware corporation (“Indivior”) and Artemis Merger Sub Inc., a Delaware corporation and a wholly owned subsidiary of Indivior (“Merger Sub”), entered into an Agreement and Plan of Merger (the “Merger Agreement”) with Supernus Pharmaceuticals, Inc., a Delaware corporation (“Supernus”). The Merger Agreement provides that, upon the terms and subject to the conditions se…

Results of Operations and Financial Condition. On August 3, 2026, Indivior Pharmaceuticals, Inc. (“Indivior” or the “Company”) issued a press release reporting its financial results for the period ended June 30, 2026. The press release is furnished as Exhibit 99.1 to this Current Report on Form 8-K.

Chief Scientific Officer — Dr. Christian Heidbreder: The position of Chief Scientific Officer is being eliminated and Dr. Heidbreder's employment will terminate by the end of 2026.

Other. On May 4, 2026 the Company issued a press release announcing that it had entered into an accelerated share repurchase agreement (the “ASR Agreement”) with an investment bank counterparty (the “Counterparty Bank”) to repurchase $175.0 million (the “Prepayment Amount”) of shares of the Company’s common stock, par value $0.001 per share (the “Common Stock”), as part of the Company’s previously announced $400 million share repurchase program (the “Share Repurchase Program”). The full text…

Results of Operations and Financial Condition. On April 30, 2026, Indivior Pharmaceuticals, Inc. (“Indivior” or the “Company”) issued a press release reporting its financial results for the period ended March 31, 2026. The press release is furnished as Exhibit 99.1 to this Current Report on Form 8-K.

Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant The disclosure set forth in

Termination of a Material Definitive Agreement On March 17, 2026, the Company used a portion of the proceeds of the Convertible Notes Offering to prepay all outstanding principal, accrued interest, and associated fees under that Note Purchase Agreement fir st made as of November 4, 2024, by and among by and among RBP Global Holdings Limited, Indivior Global Holdings Limited, Piper Sandler Finance LLC, as Administrative Agent and the lenders from time to time party thereto, as amended by that…

Entry Into a Material Definitive Agreement. Indenture On March 17, 2026, Indivior Pharmaceuticals, Inc. (the “ Company ”) issued $500,000,000 principal amount of its 0.625% Convertible Senior Notes due 2031 (the “ Notes ”; the “ Convertible Notes Offering ”). The Notes were issued pursuant to, and are governed by, an indenture (the “ Indenture ”), dated as of March 17, 2026, between the Company and U.S. Bank Trust Company, National Association, as trustee (the “ Trustee ”). Pursuant to the pu…

The Notes were issued to the initial purchasers in reliance upon Section 4(a)(2) of the Securities Act of 1933, as amended (the “ Securities Act ”), in transactions not involving any public offering. The Notes were resold by the initial purchasers to persons whom the initial purchasers reasonably believed are “qualified institutional buyers,” as defined in, and in accordance with, Rule 144A under the Securities Act. Any shares of the Company’s common stock that may be issued upon conversion o…

Other Events. On March 12, 2026, the Company announced the pricing of its offering of 0.625% convertible senior notes due 2031 (the “Notes”). A copy of the press release is filed as 99.1 to this Current Report on Form 8-K. Neither this Current Report on Form 8-K nor the press release constitutes an offer to sell, or the solicitation of an offer to buy, the Notes or the shares of the Company’s common stock, if any, issuable upon conversion of the Notes.

Other Events. On March 12, 2026, the Company announced the launch of its proposed offering of convertible senior notes due 2031 (the “Notes”). A copy of the press release is filed as 99.1 to this Current Report on Form 8-K. Neither this Current Report on Form 8-K nor the press release constitutes an offer to sell, or the solicitation of an offer to buy, the Notes or the shares of the Company’s common stock, if any, issuable upon conversion of the Notes.

Results of Operations and Financial Condition. On February 26, 2026, Indivior Pharmaceuticals, Inc. (“Indivior” or the “Company”) issued a press release reporting its financial results for the period ended December 31, 2025. The press release is furnished as Exhibit 99.1 to this Current Report on Form 8-K.

Other Events. Description of Indivior U.S. Capital Stock Indivior U.S. has one class of securities registered under Section 12 of the Exchange Act: its common stock. The following description of Indivior U.S.’s capital stock is a summary. This summary is subject to the General Corporation Law of the State of Delaware (the “ DGCL ”) and the complete text of the Certificate and Bylaws which are incorporated herein by reference. General Indivior U.S.’s authorized capital stock consists of 700,00…

Director: The filing discloses the continuation of the existing board and executive team following a corporate domestication (redomestication) event, rather than a departure, hire, or election.

Unregistered Sale of Equity Securities. The information set forth in the Introductory Note of this Current Report on Form 8-K is incorporated by reference into this

Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant. The information set forth under the heading “Note Purchase Agreement” under

Material Modification to the Rights of Security Holders. The information set forth in the Introductory Note and

Amendment to Note Purchase Agreement Effective January 26, 2026, following the effectiveness of the U.S. Domestication, RBP Global Holdings Limited, Piper Sandler Finance LLC, as Administrative Agent and the lenders from time to time party thereto entered into that certain First Amendment to Note Purchase Agreement with respect to the Note Purchase Agreement, dated as of November 4, 2024 (the “Note Purchase Agreement”), by and among RBP Global Holdings Limited, Indivior Global Holdings Limite…

Changes in Control of Registrant. The information set forth in the Introductory Note of this Current Report on Form 8-K is incorporated by reference into this

CEO — Joseph Ciaffoni: The filing discloses routine annual base salary increases for the CEO and CFO, not a change in personnel or management structure.

Termination of a Material Agreement On November 20, 2025, Indivior, PLC (the “Registrant,” or the “Company,”) announced that it had satisfied its remaining obligations under that certain Resolution Agreement by and among Indivior Inc., Indivior PLC, the United States Attorney’s Office for the Western District of Virginia, and the United States Department of Justice’s Consumer Protection Branch made as of July 24, 2020 (the "Resolution Agreement"). As a result, the Resolution Agreement termina…

Results of Operations and Financial Condition. On October 30, 2025, Indivior PLC (“Indivior” or the “Company”) issued a press release reporting its financial results for the period ended September 30, 2025. The press release is furnished as Exhibits 99.1 to this Current Report on Form 8-K.

Costs Associated with Exit or Disposal Activities. The management team of Indivior PLC (“Indivior” or the “Company”), with oversight of the Company's Board of Directors, approved an enterprise-wide initiative – the Indivior Action Agenda – that started in the second quarter of 2025. The Indivior Action Agenda, as disclosed on July 31 st , is a three-phased, multi-year operational roadmap intended to maximize the potential of Indivior’s business and make a positive difference in the lives of p…

Costs Associated with Exit or Disposal Activities. The current management team of Indivior PLC (“Indivior” or the “Company”), with the oversight of the Company's Board of Directors, approved an enterprise-wide initiative – the Indivior Action Agenda – that started in the second quarter of 2025. The Indivior Action Agenda, as disclosed on July 31 st , is a three-phased, multi-year operational roadmap intended to maximize the potential of Indivior’s business and make a positive difference in th…

CFO — Ryan Preblick: The filing discloses a routine renewal of an existing CFO's employment agreement with no changes to compensation, title, or responsibilities, which is a non-management administrative matter.