Alkermes plc.

During the three months ended September 30, 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 August 6, 2026, Dr. Cato Laurencin, adirector of the Company, adopted a Rule 10b5-1 plan providing for the sale of up to 16,142 ordinary shares of the Company that may be obtained from the exercise of stock options; this plan is scheduled to expire on December 31, 2027; (ii) on August 21, 2026, Dr. Christopher Wright, adirector of the Company, adopted a Rule 10b5-1 plan providing for the sale of up to 39,297 ordinary shares of the Company that may be obtained from the exercise of stock options or the vesting of restricted stock unit awards; this plan is scheduled to expire on November 18, 2027; and (iii) on August 31, 2026, Shane Cooke, adirector of the Company, adopted a Rule 10b5-1 plan providing for the sale of up to 41,675 ordinary shares of the Company, including 21,675 that may be obtained from the exercise of expiring stock options; this plan is scheduled to expire on August 31, 2027. During the three months ended September 30, 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.