X0303 4 2011-04-20 0 0000897448 AMARIN CORP PLC\UK AMRN 0001405279 Ahlholm Frederick W C/O AMARIN PHARMA, INC. MYSTIC PACKER BLDG, 12 ROOSEVELT AVENUE MYSTIC CT 06355 0 1 0 0 Vice President Finance Ordinary Shares 2011-04-20 4 M 0 31250 1.70 A 31250 D Ordinary Shares 2011-04-20 4 S 0 31250 15.8830 D 0 D Stock Option (right to buy) 1.70 2011-04-20 4 M 0 31250 0 D 2020-04-20 Ordinary Shares 31250 187500 D The Ordinary Shares may be represented by American Depositary Shares, each of which currently represents one Ordinary Share. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $15.69 to $16.00, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range. On April 20, 2010, the reporting person was granted an option to purchase 250,000 ordinary shares under the Amarin Corporation plc 2002 Stock Option Plan. The stock option initially vested in four equal installments on each anniversary of such grant date. In December 2010, the Issuer's Board of Directors approved the acceleration of the vesting of this award by six months such that the option vests in four equal installments beginning on October 20, 2010 and ending on October 20, 2013. /s/ Frederick Ahlholm 2011-04-20