AMARIN CORP PLC\UK — Director's Dealing 2019

May 21, 2019

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: AMARIN CORP PLC\UK (AMRN)
CIK: 0000897448
Period of Report: 2019-05-17

Reporting Person: STACK DAVID M (Director)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2019-05-17	Ordinary Shares	M	13174	$3.21	Acquired	13174	Direct
2019-05-17	Ordinary Shares	S	13174	$18.0005	Disposed	0	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2019-05-17	Stock Option (Right to Buy)	$3.21	M	13174	Disposed	2028-05-14	Ordinary Shares (13174)	Direct
2019-05-20	Stock Option (Right to Buy)	$16.83	A	9658	Acquired	2029-05-20	Ordinary Shares (9658)	Direct
2019-05-20	Restricted Stock Units	$0.00	A	7428	Acquired		Ordinary Shares (7428)	Direct

Footnotes

F1: The option exercises and sale transactions reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan previously adopted by the Reporting Person.

F2: The Ordinary Shares may be represented by American Depositary Shares, each of which currently represents one Ordinary Share.

F3: Please see the section titled "Remarks" below for additional information.

F4: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $18.00 to $18.01, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range.

F5: The stock option granted to the Reporting Person is fully vested as of the date hereof.

F6: On May 20, 2019, the Reporting Person was granted an option to purchase 9,658 Ordinary Shares under the Amarin Corporation plc 2011 Stock Incentive Plan (the "Plan"). The option shall vest and become exercisable in a single annual installment upon the earlier of (i) the anniversary of the grant date of May 20, 2019 or (ii) the Issuer's annual general meeting of shareholders in 2020.

F7: Each Restricted Stock Unit ("RSU") represents a contingent right to receive one Ordinary Share or cash in lieu thereof at the Issuer's discretion, with settlement to be made on a deferred basis, specifically upon the non-employee director's separation of service with the Issuer.

F8: On May 20, 2019, the Reporting Person was granted 7,428 RSUs under the Plan. The RSUs vest in equal annual installments over a three-year period, with each installment vesting upon the earlier of (i) the anniversary of the grant date of May 20, 2019 or (ii) the Issuer's annual general meeting of shareholders in such year.

F9: Not applicable.