Alkermes plc. — Director's Dealing 2012

May 22, 2012

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: Alkermes plc. (ALKS)
CIK: 0001520262
Period of Report: 2012-05-21

Reporting Person: Pugh Gordon G (SVP, COO & CRO, Alkermes, Inc.)

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2012-05-21	Employee Stock Option (Right to Buy)	$16.55	A	110000	Acquired	2022-05-21	Ordinary Shares (110000)	Direct
2012-05-21	Restricted Stock Unit Award	$0	A	16500	Acquired		Ordinary Shares (16500)	Direct

Footnotes

F1: Stock option award granted under the Alkermes plc 2011 Stock Option and Incentive Plan. Shares subject to the stock option vest in four equal annual installments commencing on 5/21/13.

F2: Restricted stock unit award granted under the Alkermes plc 2011 Stock Option and Incentive Plan. Shares subject to the award vest in four equal annual installments commencing on 5/21/13.