Alkermes plc. — Director's Dealing 2013

Jan 10, 2013

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: Alkermes plc. (ALKS)
CIK: 0001520262
Period of Report: 2013-01-09

Reporting Person: Peterson Rebecca (SVP, Corporate Communications)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2013-01-09	Ordinary Shares	M	7500	$15.95	Acquired	7500	Direct
2013-01-09	Ordinary Shares	M	8750	$18.105	Acquired	16250	Direct
2013-01-09	Ordinary Shares	S	16250	$22.00	Disposed	0	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2013-01-09	Employee Stock Option (Right to Buy)	$15.95	M	7500	Disposed	2017-06-01	Ordinary Shares (7500)	Direct
2013-01-09	Employee Stock Option (Right to Buy)	$18.11	M	8750	Disposed	2021-05-20	Ordinary Shares (8750)	Direct

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

F4: Vests in 4 equal annual installments commencing on 5/20/12.