Supernus Pharmaceuticals, Inc.

Item 8.01 Other Events. As previously announced, on August 3, 2026, Supernus Pharmaceuticals, Inc. (the “Company”) and Indivior Pharmaceuticals Inc. (“Indivior”) are hosting a conference call and webcast at 8:30 a.m., Eastern Time, to present information regarding the proposed merger of the Company and Indivior. The Company intends to display the slides filed as Exhibit 99.1 hereto during the presentation. Important Additional Information and Where to Find It In connection with the proposed transaction, Indivior intends to file with the SEC a registration statement on Form S-4, which will include a document that serves as a prospectus of Indivior and a joint proxy statement of Indivior and Supernus (the “joint proxy statement/prospectus”). Each party also plans to file other relevant documents with the SEC regarding the proposed transaction. INVESTORS AND SECURITY HOLDERS ARE URGED TO READ THE JOINT PROXY STATEMENT/PROSPECTUS AND OTHER RELEVANT DOCUMENTS FILED WITH THE SEC WHEN THEY BECOME AVAILABLE, BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION ABOUT THE PROPOSED TRANSACTION. A definitive joint proxy statement/prospectus will be sent to Indivior’s stockholders and Supernus’ stockholders. Investors and securityholders may obtain a free copy of the joint proxy statement/prospectus (if and when it becomes available) and other relevant documents filed by Indivior and Supernus with the SEC at the SEC’s website at www.sec.gov. Copies of the documents filed by Indivior with the SEC will be available free of charge on Indivior’s website at www.indivior.com or by contacting Indivior’s Investor Relations at InvestorRelations@indivior.com. Copies of the documents filed by Supernus with the SEC will be available free of charge on Supernus’ website at www.supernus.com. No Offer or Solicitation This report and the information contained herein is for informational purposes only and does not constitute an offer to sell or the solicitation of an offer to buy or exchange any securities, or a solicitation of any vote or approval, nor shall there be any sale of securities in any jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such jurisdiction. This report does not constitute a prospectus or prospectus equivalent document. No offer of securities shall be made except by means of a prospectus meeting the requirements of Section 10 of the Securities Act of 1933, as amended. Participants in the Solicitation Indivior and Supernus and their respective directors, executive officers and other members of management and employees may be deemed to be participants in the solicitation of proxies in respect of the proposed transaction. Information about directors and executive officers of Indivior is available in the Indivior proxy statement for its 2026 Annual Meeting, which was filed with the SEC on March 27, 2026. Information about directors and executive officers of Supernus is available in the Supernus proxy statement for its 2026 Annual Meeting, which was filed with the SEC on April 30, 2026. Other information regarding the participants in the proxy solicitation and a description of their direct and indirect interests, by security holdings or otherwise, will be contained in the joint proxy statement/prospectus and other relevant materials filed with the SEC regarding the proposed transaction when they become available. Investors should read the joint proxy statement/prospectus carefully when it becomes available before making any voting or investment decisions. Investors may obtain free copies of these documents from Indivior and Supernus as indicated above.