Announcement relating to despatch of Rule 15 proposal

Core Viewpoint - Alkermes plc has reached an agreement to acquire Avadel Pharmaceuticals plc, with the transaction structured as a scheme of arrangement under Irish law [1][8]. Group 1: Proposed Transaction Details - The acquisition involves Alkermes acquiring the entire issued and to be issued ordinary share capital of Avadel [1]. - The Proposed Transaction will be implemented through a scheme of arrangement under Chapter 1 of Part 9 of the Irish Companies Act 2014 [1][8]. - A joint letter detailing the proposal has been sent to Avadel Equity Award Holders and ESPP Participants [2]. Group 2: Company Profiles - Alkermes is a global biopharmaceutical company focused on developing innovative medicines for neurological disorders, with a portfolio that includes treatments for alcohol and opioid dependence, schizophrenia, and bipolar I disorder [4]. - Avadel Pharmaceuticals specializes in transforming medicines to improve patient outcomes, with its commercial product LUMRYZ™ approved for treating narcolepsy [5][6]. Group 3: Additional Information - The Rule 15 Proposal is available for inspection on both Avadel's and Alkermes' websites [3]. - Avadel filed a definitive proxy statement with the U.S. Securities and Exchange Commission on December 3, 2025, which includes important information regarding the Proposed Transaction [9][11].