X0609 4 2026-07-01 0001520262 Alkermes plc. ALKS 0001730048 Hopkinson Craig C. false 900 WINTER STREET WALTHAM MA 02451 1 EVP R&D, Chief Medical Officer 1 Ordinary Shares 2026-07-01 4 M 0 5000 19.34 A 82389 D Ordinary Shares 2026-07-01 4 S 0 8300 51.4613 D 74089 D Ordinary Shares 2026-07-01 4 S 0 700 52.1314 D 73389 D Employee Stock Option (Right to Buy) 19.34 2026-07-01 4 M 0 5000 0 D 2031-02-22 Ordinary Shares 5000 1356 D This option exercise was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on 3/14/2025. This sale was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on 3/14/2025. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $51.06 to $52.04. Full information regarding the number of shares sold at each separate price can be provided to the issuer, any security holder of the issuer or the SEC staff upon request. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $52.10 to $52.17. Full information regarding the number of shares sold at each separate price can be provided to the issuer, any security holder of the issuer or the SEC staff upon request. These options are fully vested in accordance with their terms. /s/ Shantale Greenson, attorney-in-fact for Craig C. Hopkinson 2026-07-01