LNTH: Material agreement · Leadership change

Item 1.01 Entry into a Material Definitive Agreement Merger Agreement 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. Effect on Capital Stock Upon the terms and subject to the conditions set forth in the Merger Agreement, at the effective time of the Merger (the “ Effective Time ”), each issued and outstanding share of common stock of the Company, par value $0.01 per share (the “ Company Common Stock ”), other than (i) shares that, immediately prior to the Effective Time, are owned by the Company as treasury stock or owned by Parent or Merger Sub or any other subsidiary of Parent or any Company subsidiary (other than, in each case, Company Common Stock that is held in a fiduciary or agent capacity and is beneficially owned by third parties) and (ii) shares issued and outstanding immediately prior to the Effective Time and held by a holder who did not vote in favor of the adoption of the Merger Agreement, and is entitled to demand and properly exercises and demands appraisal of such shares pursuant to, and who complies in all respects with the Delaware General Corporation Law, will be automatically converted into the right to receive (x) $102.50 per share in cash, without interest (the “ Per Share Cash Consideration ”) and (y) on