Alkermes plc.

During the three months ended March 31, 2026, the following contracts, instructions or written plans for the purchase or sale of the Company’s securities that are or were intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) under the Exchange Act (each, a “Rule 10b5-1 plan”) were adopted by officers (as defined in Rule 16a-1(f) under the Exchange Act) and directors of the Company: (i) on March 11, 2026, Christopher Wright, M.D., Ph.D., a director of the Company, adopted a Rule 10b5-1 plan providing for the sale of up to 2,000 ordinary shares of the Company that may be obtained from the vesting of restricted stock unit awards; this plan is scheduled to expire on December 31, 2026; and (ii) on March 12, 2026, Richard Pops, our Chairman and Chief Executive Officer, adopted a Rule 10b5-1 plan providing for the sale of up to 203,999 ordinary shares of the Company that may be obtained from the exercise of expiring stock options; this plan is scheduled to expire on February 17, 2027. During the three months ended March 31, 2026, no other directors or officers of the Company adopted or terminated a Rule 10b5-1 plan or a trading plan not intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) under the Exchange Act.