Director awarded options and RSUs; Form 4/A corrects vesting terms

### 4/A - PRIMARY DOCUMENT
SEC FORM
4/A SEC Form 4
FORM 4 | UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940 | OMB APPROVAL |
OMB Number: | 3235-0287 |
Estimated average burden |
hours per response: | 0.5 |

|

|
   |

| Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue.
See

Instruction 1(b). |
   |

| Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10. |

1. Name and Address of Reporting Person * GAYNOR RICHARD |

(Last) | (First) | (Middle) |

CONNAUGHT HOUSE |
1 BURLINGTON ROAD |

(Street) DUBLIN | | 4 Ireland |

(City) | (State) | (Zip) |

IRELAND
|

(Country) | 2. Issuer Name and Ticker or Trading Symbol

Alkermes plc.
[ ALKS ]
| 5. Relationship of Reporting Person(s) to Issuer

(Check all applicable) X | Director | | 10% Owner |
| Officer (give title below) | | Other (specify below) |
| | | |

|
2a. Foreign Trading Symbol

|
3. Date of Earliest Transaction
(Month/Day/Year)
05/20/2026 | 6. Individual or Joint/Group Filing (Check Applicable Line)
X | Form filed by One Reporting Person |
| Form filed by More than One Reporting Person |

|
4. If Amendment, Date of Original Filed
(Month/Day/Year)
05/22/2026
|

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 |

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 Securities Underlying Derivative Security (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: 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 |
Non Qualified Stock Option (Right to Buy) | $ 36.98 | 05/20/2026 | | A | | 11,538 | |

(1) (2) | 05/20/2036 | Ordinary Shares | 11,538 | $ 0 | 11,538 | D | |
Restricted Stock Unit Award | (3) | 05/20/2026 | | A | | 5,409 | |

(1) (2) |

(1) (2) | Ordinary Shares | 5,409 | $ 0 | 5,409 | D | |

Explanation of Responses: |
1. Shares subject to the award vest (and if applicable, become exercisable) in full on the earlier of the one-year anniversary of the date of grant or the date of the issuer's next annual general meeting of shareholders that occurs at least 50 weeks after the date of grant. |
2. This amendment is being filed to reflect the vesting terms applicable to this award, which were reported incorrectly on the original Form 4. The correct vesting schedule is set forth in Footnote 1 above. |
3. Each restricted stock unit represents a contingent right to receive one ordinary share. |

| /s/ Shantale Greenson, attorney-in-fact for Richard Gaynor | 05/22/2026 |
| ** Signature of Reporting Person | Date |
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly. |
* 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). |
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient,
see

Instruction 6 for procedure. |
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 Number. |
* Form 4: SEC 1474 (03-26) |

### 4/A - PRIMARY DOCUMENT
X0609

4/A

2026-05-20

2026-05-22

0001520262
Alkermes plc.
ALKS

0001741284
GAYNOR RICHARD

true
CONNAUGHT HOUSE
1 BURLINGTON ROAD
DUBLIN

L2
4 Ireland
IRELAND

1

0

Non Qualified Stock Option (Right to Buy)

36.98

2026-05-20

4
A
0

11538

0

A

2036-05-20

Ordinary Shares

11538

11538

D

Restricted Stock Unit Award

2026-05-20

4
A
0

5409

0

A

Ordinary Shares

5409

5409

D

Shares subject to the award vest (and if applicable, become exercisable) in full on the earlier of the one-year anniversary of the date of grant or the date of the issuer's next annual general meeting of shareholders that occurs at least 50 weeks after the date of grant.
This amendment is being filed to reflect the vesting terms applicable to this award, which were reported incorrectly on the original Form 4. The correct vesting schedule is set forth in Footnote 1 above.
Each restricted stock unit represents a contingent right to receive one ordinary share.

/s/ Shantale Greenson, attorney-in-fact for Richard Gaynor
2026-05-22