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

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1. Name and Address of Reporting Person * GREY MICHAEL G   2. Issuer Name and Ticker or Trading Symbol Horizon Pharma plc [HZNP] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director _____ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) C/O HORIZON PHARMA, INC., 520 LAKE COOK ROAD, SUITE 520 3. Date of Earliest Transaction (Month/Day/Year) 09/19/2014 (Street) DEERFIELD, IL 60015 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

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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

Stock Option (Right to Buy)

$ 3.95

09/19/2014

D(1)

5,265

(2)

06/07/2022

Common Stock

5,265

(3)

0

D

Stock Option (Right to Buy)

$ 2.37

09/19/2014

D(1)

20,000

(2)

05/30/2023

Common Stock

20,000

(3)

0

D

Stock Option (Right to Buy)

$ 15.96

09/19/2014

D(1)

20,000

(4)

06/26/2024

Common Stock

20,000

(3)

0

D

Stock Option (Right to Buy)

$ 7.48

09/19/2014

D(1)

10,530

(5)

09/28/2014

Common Stock

10,530

(3)

0

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
GREY MICHAEL G C/O HORIZON PHARMA, INC. 520 LAKE COOK ROAD, SUITE 520 DEERFIELD, IL 60015	X

Signatures

/s/ Robert J. De Vaere, Attorney-in-Fact		09/22/2014
**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)	Disposition in connection with the merger (the "Merger") contemplated by the Transaction Agreement and Plan of Merger among Horizon Pharma, Inc. (the "Issuer"), Vidara Therapeutics Holdings LLC, Horizon Pharma plc (formerly known as Vidara Therapeutics International Ltd.), Hamilton Holdings (USA), Inc. and Hamilton Merger Sub, Inc. Pursuant to the Merger, the outstanding securities of the Issuer are being canceled and automatically converted into securities of Horizon Pharma plc. The Reporting Person's acquisition of securities of Horizon Pharma plc in the Merger will be reported on a separate Form 4.
(2)	The stock option vested in 12 equal monthly installments following the grant date, and is fully vested and exercisable.
(3)	In connection with the Merger, the stock option has been assumed and converted into options to purchase the same number of ordinary shares of Horizon Pharma plc at the same exercise price and on substantially the same terms.
(4)	The stock option vests in 12 equal monthly installments following the grant date of 6/27/2014.
(5)	The stock option vests in 36 equal monthly installments following the grant date of 9/29/2011.

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