X0508 4 2026-01-02 0001520262 Alkermes plc. ALKS 0001730048 Hopkinson Craig C. 900 WINTER ST. WALTHAM MA 02451 1 EVP R&D, Chief Medical Officer 1 Ordinary Shares 2026-01-02 4 S 0 4000 28.00 D 61740 D This sale was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on 3/14/2025. /s/ Shantale Greenson, attorney-in-fact for Craig C. Hopkinson 2026-01-02