LNTH: Other company developments

Item 8.01 Other Events. As previously disclosed, on August 3, 2026, Lantheus Holdings, Inc., a Delaware corporation (“ Lantheus ” or the “ Company ”), entered into an Agreement and Plan of Merger (the “ Merger Agreement ”) by and among the Company, Curium US Holdings LLC, a Delaware limited liability company (“ Parent ”), and Coco Merger Sub Inc., a Delaware corporation and a wholly owned subsidiary of Parent (“ Merger Sub ”), pursuant to which, subject to the terms and conditions set forth therein, Merger Sub will merge with and into the Company (the “ Merger ”), with the Company surviving the Merger as a wholly owned subsidiary of Parent. On September 8, 2026, the Company filed a definitive proxy statement with the Securities and Exchange Commission (the “ SEC ”) relating to the special meeting of its stockholders to be held on October 14, 2026 (the “ Special Meeting ”) to consider and vote on the approval of the Merger Agreement and several related proposals (the “ Definitive Proxy Statement ”). Defined terms used but not defined herein have the meanings set forth in the Definitive Proxy Statement. Certain Litigation Since the filing of the Definitive Proxy Statement, three complaints have been filed against the Company and certain members of the Board in connection with the Merger. Two such complaints were filed in the Supreme Court of the State of New York, County of New York: Hamilton v. Lantheus Holdings, Inc., et al. , Index No. 655291/2026, filed on September 16, 2026, and McDaniels v. Lantheus Holdings, Inc., et al. , Index No. 655281/2026, filed on September 16, 2026, and one was filed in the Superior Court of the Commonwealth of Massachusetts, Middlesex County: Garfield v. Lantheus Holdings, Inc., et al. , Civil Docket No. 2681CV02581, filed on September 25,