Business Description

1. DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION Alkermes plc is a global biopharmaceutical company that seeks to develop innovative medicines in the field of neuroscience. Alkermes has a portfolio of proprietary commercial products for the treatment of alcohol dependence and opioid dependence, schizophrenia, bipolar I disorder and narcolepsy and a pipeline of clinical and preclinical candidates in development for neurological disorders. Headquartered in Ireland, Alkermes also has a corporate office and research and development (“R&D”) center in Massachusetts and a manufacturing facility in Ohio. In October 2025, the Company and Avadel Pharmaceuticals plc (“Avadel”) entered into a definitive transaction agreement, subsequently amended in November 2025 (the “Transaction Agreement”), pursuant to which the Company agreed to acquire the entire issued and to be issued ordinary share capital of Avadel for consideration of (i) $ 21.00 per ordinary share, nominal value $ 0.01 per share, of Avadel (each, an “Avadel Share”), payable in cash at closing and (ii) a non-transferable contingent value right (the “CVR”) entitling holders of Avadel Shares to a potential additional cash payment of $ 1.50 per Avadel Share, contingent upon achievement of a certain specified milestone (the “Avadel Acquisition”). The Company incurred costs of approximately $ 10.0 million in connection with the Avadel Acquisition during the fourth quarter of 2025. On February 12, 2026, the Company successfully completed the Avadel Acquisition, adding both LUMRYZ to the Company’s portfolio of proprietary commercial products and a commercial organization with experience in narcolepsy. In May 2024, the Company completed the sale of its development and manufacturing facility in Athlone, Ireland (the “Athlone Facility”) and related business to Novo Nordisk (“Novo”) pursuant to an asset purchase agreement entered into in December 2023. The Company and Novo also entered into subcontracting arrangements to continue certain development and manufacturing activities performed at the Athlone Facility for a period of time after the closing of the transaction, which activities concluded by the end of 2025. In connection with the sale of the Athlone Facility, the Company received $ 97.9 million from Novo, which included a payment of approximately $ 91.0 million for the facility and certain related assets, and recorded a gain of approximately $ 1.5 million within “ Other income (expense), net ” in the accompanying consolidated statements of operations and comprehensive income for the year ended December 31, 2024. In November 2023, the Company completed the separation of its former oncology business into Mural Oncology plc (“Mural”), a new, independent, publicly-traded company (the “Separation”). The Separation was effected by means of a distribution of all of the outstanding ordinary shares of Mural to the Company’s shareholders (the “Distribution”), in which each of the Company’s shareholders received one ordinary share, nominal value $ 0.01 per share, of Mural for every ten ordinary shares, par value $ 0.01 per share, of the Company (the “Distribution Ratio”) held by such shareholder as of the close of business on November 6, 2023, the record date for the Distribution (the “Record Date”). The historical results of the oncology business have been reflected as discontinued operations in the Company’s consolidated financial statements through November 15, 2023 (the “Separation Date”). For additional information related to the Separation, see Note 15, Discontinued Operations in these “Notes to Consolidated Financial Statements” in this Annual Report.