Alkermes plc, a global biopharmaceutical company, develops and commercializes proprietary medicines that address unmet medical needs in neuroscience, focusing on serious mental illnesses, addiction, and neurological disorders including schizophrenia, bipolar I disorder, alcohol dependence, opioid dependence, and narcolepsy; its core proprietary products include Vivitrol for alcohol and opioid dependence, Aristada and Aristada Initio for schizophrenia, and Lybalvi for schizophrenia and bipolar I disorder. The company also derives revenue from manufacturing services and royalties on partnered products utilizing its proprietary technologies such as long-acting injectable formulations. Founded in 1987 and headquartered in Dublin, Ireland, with key research and development operations in Waltham, Massachusetts, and manufacturing facilities in Athlone, Ireland, Wilmington, Ohio, and Gainesville, Georgia, Alkermes conducts business primarily in the United States and internationally. In a significant strategic development, Alkermes announced in October 2025 a definitive agreement to acquire Avadel Pharmaceuticals plc for up to $2.37 billion, including $21.00 per share in cash plus a $1.50 contingent value right, enhancing its neuroscience portfolio with Avadel's Lumryz, an FDA-approved once-at-night sodium oxybate for narcolepsy, and accelerating entry into the sleep medicine market ahead of potential phase 3 advancement of alixorexton; the transaction, approved by both boards, awaits regulatory approvals and shareholder votes with closure expected in the first quarter of 2026. Alkermes advances a neuroscience pipeline featuring investigational orexin 2 receptor agonists such as alixorexton (formerly ALKS 2680) in phase 2 for narcolepsy and idiopathic hypersomnia—recently reporting positive topline results from the Vibrance-2 study in narcolepsy type 2—alongside ALKS 4510 and ALKS 7290 in phase 1, and olanzapine/samidorphan in phase 3 for pediatric schizophrenia and bipolar I disorder.