AMARIN CORP PLC\UK — Director's Dealing 2021

Mar 1, 2021

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: AMARIN CORP PLC\UK (AMRN)
CIK: 0000897448
Period of Report: 2021-02-25

Reporting Person: THERO JOHN F (N/A)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2021-02-25	Ordinary Shares	M	390696.00	—	Acquired	3272445.00	Direct
2021-02-25	Ordinary Shares	F	153739.00	$7.30	Disposed	3118706.00	Direct
2021-02-26	Ordinary Shares	M	6736.00	—	Acquired	3125442.00	Direct
2021-02-26	Ordinary Shares	M	6736.00	—	Acquired	3132178.00	Direct
2021-02-26	Ordinary Shares	M	13472.00	—	Acquired	3145650.00	Direct
2021-02-26	Ordinary Shares	F	10604.00	$6.74	Disposed	3135046.00	Direct
2021-02-26	Ordinary Shares	M	59367.00	—	Acquired	3194413.00	Direct
2021-02-26	Ordinary Shares	F	23361.00	$6.74	Disposed	3171052.00	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2021-02-25	Restricted Stock Units	$0.00	M	390696.00	Disposed		Ordinary Shares (390696.00)	Direct
2021-02-26	Restricted Stock Units	$0.00	M	6736.00	Disposed		Ordinary Shares (6736.00)	Direct
2021-02-26	Restricted Stock Units	$0.00	M	6736.00	Disposed		Ordinary Shares (6736.00)	Direct
2021-02-26	Restricted Stock Units	$0.00	M	13472.00	Disposed		Ordinary Shares (13472.00)	Direct
2021-02-26	Restricted Stock Units	$0.00	M	59367.00	Disposed		Ordinary Shares (59367.00)	Direct

Footnotes

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

F2: As previously reported, on May 15 2017, the Reporting Person was granted 970,000 Restricted Stock Units ("RSUs") under the Amarin Corporation plc 2011 Stock Incentive Plan (the "Plan"). These RSUs consist of 3 tranches representing 25%, 25% and 50% of the total award. Each tranche vests ratably over 36 months beginning Sept. 30 2018 subject to achievement of certain prespecified performance criteria and continued service of the Reporting Person as provided in the RSU Award Agreement between the Issuer and Reporting Person. On Feb. 25 2021, pursuant to reporting of audited net total revenue for 2020 exceeding $500 million, the performance criteria related to the 50% tranche was deemed achieved, resulting in the vesting of 390,696 RSUs (29 of 36 months' worth). The remaining RSUs in this tranche will continue to vest over 7 monthly installments, the first of which vested Feb. 26 2021. The performance criteria related to both 25% tranches were previously deemed achieved (see Footnote 5).

F3: Not applicable.

F4: 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.

F5: As previously reported on February 27, 2020 and herewith in Footnote 2, on May 15, 2017, the Reporting Person was granted 970,000 RSUs under the Plan, of which the performance criteria related to two tranches representing 25% of the total award each was deemed achieved on February 25, 2020 pursuant to reporting of audited net product revenues for 2019 exceeding $400 million and of which the performance criteria related to one tranche representing 50% of the total award was deemed achieved on February 25, 2021 pursuant to reporting of audited net product revenues for 2020 exceeding $500 million. The tranches vest ratably over 36 months beginning September 30, 2018 subject to achievement of the performance criteria and continued service of the Reporting Person as provided in the RSU Award Agreement between the Issuer and Reporting Person. The thirtieth vesting event occurred on February 26, 2021.

F6: On March 2, 2020, the Reporting Person was granted 178,100 RSUs under the Plan. These RSUs vest in three equal installments on each of February 28, 2021, February 28, 2022 and February 28, 2023. The first vesting event occurred on February 26, 2021.

F7: Please see the section titled "Remarks" below for additional information.

F8: Each RSU represents a contingent right to receive one Ordinary Share or cash in lieu thereof at the Issuer's discretion.