AMRN Amarin Corp PLC

On August 11, 2016, Amarin Corporation plc (the “Company,” “we,” “us” and “our”) entered into an Underwriting Agreement (the “Underwriting Agreement”) with Citigroup Global Markets Inc. and Jefferies LLC, as representatives of the several underwriters listed therein (the “Underwriters”), relating to the issuance and sale (the “Offering”) of up to 21,100,000 American Depositary Shares (“ADSs”), including 3,165,000 ADSs issuable to the Underwriters pursuant to a 30-day option, with each ADS representing one of the Company’s ordinary shares, par value £0.50 per share. The price to the public in this offering is $2.85 per ADS, and the Underwriters have agreed to purchase the ADSs from Amarin pursuant to the Underwriting Agreement at a price of $2.679 per ADS. The net proceeds to us from the Offering are expected to be approximately $56.1 million, after deducting underwriting discounts and commissions and other estimated offering expenses, assuming no exercise of the option by the Underwriters. The Offering is expected to close on or about August 16, 2016, subject to customary closing conditions. The Company currently intends to use the net proceeds from the Offering to advance its REDUCE-IT cardiovascular outcomes trial and for general corporate and working capital purposes.

In the Underwriting Agreement, the Company makes customary representations, warranties and covenants and also agrees to indemnify the Underwriters against certain liabilities, including liabilities under the Securities Act of 1933, as amended, or to contribute to payments that the Underwriters may be required to make because of such liabilities. The Underwriting Agreement has been filed with this report to provide investors and security holders with information regarding its terms. It is not intended to provide any other factual information about the Company. The representations, warranties and covenants contained in the Underwriting Agreement were made only for purposes of such agreement and as of specific dates, were solely for the benefit of the parties to such agreement, and may be subject to limitations agreed upon by the contracting parties. The foregoing is only a brief description of the material terms of the Underwriting Agreement and does not purport to be a complete description of the rights and obligations of the parties thereunder. The Underwriting Agreement is filed as Exhibit 1.1 to this report, and the description of the terms of the Underwriting Agreement is qualified in its entirety by reference to such exhibit. A copy of the opinion of K&L Gates LLP relating to the legality of the issuance and sale of the ADSs in the Offering is attached as Exhibit 5.1 hereto.

The Offering was made pursuant to our effective registration statement on Form S-3 (Registration Statement No. 333-97936) previously filed with the U.S. Securities and Exchange Commission (the “SEC”) on August 7, 2014 and declared effective on August 22, 2014, and a prospectus supplement thereunder filed on August 10, 2016.