Alkermes plc. — Director's Dealing 2015

May 13, 2015

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: Alkermes plc. (ALKS)
CIK: 0001520262
Period of Report: 2015-05-12

Reporting Person: FRATES JAMES M (SVP & CFO, Alkermes plc)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2015-05-12	Ordinary Shares	M	10000	$11.74	Acquired	88649	Direct
2015-05-12	Ordinary Shares	S	10000	$59.3423	Disposed	78649	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2015-05-12	Employee Stock Option (Right to Buy)	$11.74	M	10000	Disposed	2020-05-17	Ordinary Shares (10000)	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Ordinary Shares	4000	Indirect
Ordinary Shares	57000	Indirect

Footnotes

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

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

F3: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $58.76 to $59.59. Full information regarding the number of shares sold at each separate price can be furnished to the SEC staff upon request.

F4: Shares held by James M. Frates Grantor Retained Annuity Trust dated March 14, 2014 (the "GRAT"). The Reporting Person is a trustee and beneficiary of the GRAT and may be deemed to hold voting and dispositive power with regard to the reported shares held by the GRAT.

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