UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of Report (Date of Earliest Event Reported): March 12, 2025

Amarin Corporation plc

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code: +353 1 6699 020

Not Applicable

Former name or former address, if changed since last report

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (17 CFR §230.405) or Rule 12b-2 of the Securities Exchange Act of 1934 (17 CFR §240.12b-2).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.02. Results of Operations and Financial Condition.

On March 12, 2025, Amarin Corporation plc (“Amarin”) issued a press release announcing its financial results for the three and twelve months ended December 31, 2024 and 2023 (the “Press Release”). A copy of the Press Release is furnished herewith as Exhibit 99.1.

The information in this report furnished pursuant to Item 2.02 shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section. It may only be incorporated by reference in another filing under the Exchange Act or the Securities Act of 1933, as amended (the “Securities Act”), if such subsequent filing specifically references the information furnished pursuant to Item 2.02 of this report.

Item 3.03 Material Modification to Rights of Security Holders.

On March 12, 2025, Amarin announced its intent to effect an adjustment in the ratio of its American depositary shares (“ADSs”) to its ordinary shares, £0.50 par value per share (“Ordinary Shares”) from one (1) ADS representing one (1) Ordinary Share to one (1) ADS representing twenty (20) Ordinary Shares (the “ADS Ratio Change”). The ADS Ratio Change will result in a one for twenty reverse split of issued and outstanding ADSs, and it will have no effect on the Ordinary Shares. The ADS Ratio Change is expected to become effective on or about April 11, 2025 (the “Effective Date”).

As a result of the ADS Ratio Change, the trading price of Amarin's ADSs is expected to increase proportionally, but Amarin can give no assurance that the trading price per ADS after the ADS Ratio Change will be equal to or greater than twenty (20) times the trading price per ADS before the change.

Item 7.01 Regulation FD

On March 12, 2025, Amarin issued a press release announcing the ADS Ratio Change. A copy of this press release is furnished as Exhibit 99.2 to this Current Report on Form 8-K.

The information in this Item 7.01 and the attached Exhibit 99.1 are being furnished to the Securities and Exchange Commission and shall not be deemed “filed” for purposes of Section 18 of the Exchange Act, or otherwise subject to the liabilities of that Section, nor shall it be deemed incorporated by reference into any filing of Amarin under the Securities Act or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

Item 9.01. Financial Statements and Exhibits.

(d) Exhibits

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SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.