Alkermes plc. — Director's Dealing 2018

May 18, 2018

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: Alkermes plc. (ALKS)
CIK: 0001520262
Period of Report: 2018-05-17

Reporting Person: LANDINE MICHAEL J (SVP, Corp Dev., Alkermes, Inc.)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2018-05-17	Ordinary Shares	M	20000	$12.29	Acquired	192644	Direct
2018-05-17	Ordinary Shares	S	16900	$45.9581	Disposed	175744	Direct
2018-05-17	Ordinary Shares	S	3100	$47.1465	Disposed	172644	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2018-05-17	Employee Stock Option (Right to Buy)	$12.29	M	20000	Disposed	2018-05-27	Ordinary Shares (20000)	Direct

Footnotes

F1: This option exercise was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on 3/6/18.

F2: This sale was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on 3/6/18.

F3: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $45.53 to $46.43. Full information regarding the number of shares sold at each separate price can be furnished to the SEC staff upon request.

F4: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $46.69 to $47.56. Full information regarding the number of shares sold at each separate price can be furnished to the SEC staff upon request.

F5: These options are fully vested in accordance with their terms.