AMARIN CORP PLC\UK — Director's Dealing 2026

Feb 3, 2026

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: AMARIN CORP PLC\UK (AMRN)
CIK: 0000897448
Period of Report: 2026-01-31

Reporting Person: Ketchum Steven B (N/A)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2026-01-31	American Depositary Shares	M	2246	—	Acquired	41243	Direct
2026-01-31	American Depositary Shares	F	1235	$15.42	Disposed	40008	Direct
2026-01-31	American Depositary Shares	M	1933	—	Acquired	41941	Direct
2026-01-31	American Depositary Shares	F	1062	$15.42	Disposed	40879	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2026-01-31	Restricted Stock Unit	$0	M	2246	Acquired		American Depositary Shares (2246)	Direct
2026-01-31	Restricted Stock Unit	$0	M	1933	Acquired		American Depositary Shares (1933)	Direct
2026-02-01	Restricted Stock Unit	$0	A	8013	Acquired		American Depositary Shares (8013)	Direct
2026-02-01	Stock Option (right to buy)	$14.99	A	36060	Acquired	2036-02-01	American Depositary Shares (36060)	Direct

Footnotes

F1: Effective April 11, 2025, the Issuer implemented a ratio change that one (1) American Depositary Share ("ADS") currently represents twenty (20) Ordinary Shares ("ADS Ratio Change"). Proportionate adjustments were made to the Issuer's outstanding equity awards. The amount of securities reported on this Form 4 reflect the ADS Ratio Change.

F2: On February 21, 2023, the Reporting Person was granted 6,740 Restricted Stock Units ("RSUs") under the Amarin Corporation plc 2020 Stock Incentive Plan (the "Plan"). These RSUs vest in three equal installments on each of January 31, 2024, January 31, 2025 and January 31, 2026.

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: On February 1, 2024, the Reporting Person was granted 5,800 RSUs under the Plan. These RSUs vest in three equal installments on each of January 31, 2025, January 31, 2026 and January 31, 2027.

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

F7: On February 1, 2026, the Reporting Person was granted 8,013 RSUs under the Plan. These RSUs vest in three equal installments on each of January 31, 2027, January 31, 2028 and January 31, 2029.

F8: On February 1, 2026, the Reporting Person was granted an option to purchase 36,060 ADSs under the Plan. The shares subject to this option shall vest and become exercisable over three years, with 33% to vest on the first anniversary of the grant date and the balance to vest ratably over the subsequent 8 calendar quarters on the first day of each May, August, November and February.