Ownership Submission
FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
OMB APPROVAL
OMB Number: 3235-0287
Expires: January 31, 2005
Estimated average burden hours per response... 0.5

(Print or Type Responses)
1. Name and Address of Reporting Person *
THERO JOHN F
  2. Issuer Name and Ticker or Trading Symbol
AMARIN CORP PLC\UK [AMRN]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
President and CEO
(Last)
(First)
(Middle)
C/O AMARIN PHARMA, INC., 1430 ROUTE 206
3. Date of Earliest Transaction (Month/Day/Year)
03/31/2019
(Street)

BEDMINSTER, NJ 07921
4. If Amendment, Date Original Filed(Month/Day/Year)
6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)
2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)
4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)
5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)
6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)
7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Ordinary Shares (1) 03/31/2019   M   37,500 (2) A (3) 2,124,928 (4) D  
Ordinary Shares (1) 03/31/2019   F(5)   14,757 D $ 20.76 2,110,171 (4) D  

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number. SEC 1474 (9-02)

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)
2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)
5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)
6. Date Exercisable and Expiration Date
(Month/Day/Year)
7. Title and Amount of Underlying Securities
(Instr. 3 and 4)
8. Price of Derivative Security
(Instr. 5)
9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)
10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)
11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Restricted Stock Units (6) $ 0 03/31/2019   M     37,500   (2)   (3) Ordinary Shares (1) 37,500 $ 0 37,500 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
THERO JOHN F
C/O AMARIN PHARMA, INC.
1430 ROUTE 206
BEDMINSTER, NJ 07921
  X     President and CEO  

Signatures

 /s/ John F. Thero   04/01/2019
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) The Ordinary Shares may be represented by American Depositary Shares, each of which currently represents one Ordinary Share.
(2) As previously reported on July 8, 2015, the Reporting Person was granted 600,000 Restricted Stock Units ("RSUs") under the Amarin Corporation plc 2011 Stock Incentive Plan (the "Plan"). These RSUs vest in 16 equal quarterly installments. The fifteenth vesting event occurred on March 31, 2019.
(3) Not applicable.
(4) Please see the section titled "Remarks" below for additional information.
(5) 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.
(6) Each RSU represents a contingent right to receive one Ordinary Share or cash in lieu thereof at the Issuer's discretion.
 
Remarks:
In the case of a Change of Control (as defined in the Plan), the grants described in this Form 4 vest in full. As of the date of this Form 4, the Reporting Person owns or holds the right to acquire an aggregate of 10,219,750 Ordinary Shares of the Issuer in the form of Ordinary Shares, stock options and RSUs granted under the Amarin Corporation plc 2002 Stock Option Plan and the Plan, including but not limited to, certain performance-based Restricted Stock Units that are earned only if product revenues reach pre-defined annual milestone levels, then vest only if the recipient remains with the company for multiple years following the reporting of REDUCE-IT results.

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.

Potential persons who are to respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB number.