Form 4 Filing for Alkermes plc.

This filing details a transaction by David Joseph Gaffin, EVP, CLO of Alkermes, Inc. On May 4, 2026, Gaffin sold 2,034 ordinary shares of Alkermes plc. at a price of $33.20 per share. This transaction was executed as part of a Rule 10b5-1 trading plan adopted on November 19, 2025. Following the sale, Gaffin holds 231,558 ordinary shares. The filing is an SEC Form 4, indicating a change in beneficial ownership.