AMARIN CORP PLC\UK — Director's Dealing 2021

Jan 5, 2021

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: AMARIN CORP PLC\UK (AMRN)
CIK: 0000897448
Period of Report: 2020-12-31

Reporting Person: THERO JOHN F (N/A)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2020-12-31	Ordinary Shares	M	6736.00	—	Acquired	2753906.00	Direct
2020-12-31	Ordinary Shares	M	6736.00	—	Acquired	2760642.00	Direct
2020-12-31	Ordinary Shares	F	5302.00	$5.23	Disposed	2755340.00	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2020-12-31	Restricted Stock Units	$0.00	M	6736.00	Disposed		Ordinary Shares (6736.00)	Direct
2020-12-31	Restricted Stock Units	$0.00	M	6736.00	Disposed		Ordinary Shares (6736.00)	Direct
2021-01-04	Stock Option (Right to Buy)	$5.03	A	775000.00	Acquired	2031-01-04	Ordinary Shares (775000.00)	Direct
2021-01-04	Restricted Stock Units	$0.00	A	574100.00	Acquired		Ordinary Shares (574100.00)	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 February 27, 2020, 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 "2011 Plan"), of which the performance criteria related to two tranches representing 50% of the total award was deemed achieved on February 25, 2020 pursuant to reporting of audited net product revenues for 2019 exceeding $400 million. The tranches vest ratably over 36 months beginning September 30, 2018 subject to achievement of the performance criteria and continued employment of the Reporting Person as provided in the RSU Award Agreement between the Issuer and Reporting Person. The twenty-eighth vesting event occurred on December 31, 2020. The performance criteria related to the remaining 50% tranche has not yet been formally deemed achieved; such tranche has not lapsed as a result of achieving the other two tranches.

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

F6: Each RSU represents a contingent right to receive one Ordinary Share or cash in lieu thereof at the Issuer's discretion.

F7: On January 4, 2021, the Reporting Person was granted an option to purchase 775,000 Ordinary Shares under the Amarin Corporation plc 2020 Stock Incentive Plan (the "2020 Plan" and, together with the 2011 Plan, the "Plans"). The shares subject to this option shall vest and become exercisable over four years, with 25% to vest on the first anniversary of the grant date and the balance to vest ratably over the subsequent 12 calendar quarters on the last day of each March, June, September and December.

F8: On January 4, 2021, the Reporting Person was granted 574,100 RSUs under the 2020 Plan. These RSUs vest in three equal installments on each of December 31, 2021, December 31, 2022 and December 31, 2023.