AMARIN CORP PLC\UK — Director's Dealing 2018

Feb 2, 2018

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: AMARIN CORP PLC\UK (AMRN)
CIK: 0000897448
Period of Report: 2018-01-31

Reporting Person: THERO JOHN F (Director, President and CEO)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2018-01-31	Ordinary Shares	M	260000	—	Acquired	1416771	Direct
2018-01-31	Ordinary Shares	M	120000	—	Acquired	1536771	Direct
2018-01-31	Ordinary Shares	M	119667	—	Acquired	1656438	Direct
2018-01-31	Ordinary Shares	F	197513	$3.83	Disposed	1458925	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2018-01-31	Restricted Stock Units	$0.00	M	260000	Disposed		Ordinary Shares (260000)	Direct
2018-01-31	Restricted Stock Units	$0.00	M	120000	Disposed		Ordinary Shares (120000)	Direct
2018-01-31	Restricted Stock Units	$0.00	M	119667	Disposed		Ordinary Shares (119667)	Direct
2018-02-01	Restricted Stock Units	$0.00	A	371000	Acquired		Ordinary Shares (371000)	Direct
2018-02-01	Stock Options (Right to Buy)	$3.80	A	558000	Acquired	2028-02-01	Ordinary Shares (558000)	Direct

Footnotes

F1: The Ordinary Shares may be represented by American Depositary Shares, each of which currently represents one Ordinary Share.

F2: On February 2, 2015, the Reporting Person was granted 780,000 Restricted Stock Unit ("RSUs") under the Amarin Corporation plc 2011 Stock Incentive Plan. These RSUs vest in three equal installments on each of January 31, 2016, January 31, 2017 and January 31, 2018. The third and final vesting event occurred on January 31, 2018.

F3: Not applicable.

F4: On February 1, 2016, the Reporting Person was granted 360,000 RSUs under the Amarin Corporation plc 2011 Stock Incentive Plan. These RSUs vest in three equal installments on each of January 31, 2017, January 31, 2018 and January 31, 2019. The second vesting event occurred on January 31, 2018.

F5: On February 1, 2017, the Reporting Person was granted 359,000 RSUs under the Amarin Corporation plc 2011 Stock Incentive Plan. These RSUs vest in three equal installments on each of January 31, 2018, January 31, 2019 and January 31, 2020. The first vesting event occurred on January 31, 2018.

F6: Represents withholding by the Issuer of shares in respect of tax liability incident to the vesting of a security issued in accordance with Rule 16b-3, and not a market sale of securities.

F7: Each RSU represents a contingent right to receive one Ordinary Share or cash in lieu thereof at the Issuer's discretion.

F8: Please see the section titled "Remarks" below for additional information.

F9: On February 1, 2018, the Reporting Person was granted 371,000 RSUs under the Amarin Corporation plc 2011 Stock Incentive Plan. These RSUs vest in three equal installments on each of January 31, 2019, January 31, 2020 and January 31, 2021.

F10: On February 1, 2018, the Reporting Person was granted an option to purchase 558,000 Ordinary Shares under the Amarin Corporation plc 2011 Stock Incentive Plan. The shares subject to this option shall vest and become exercisable in 48 equal monthly installments on the last day of each month starting on February 28, 2018.