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UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 4)*

If the filing person has previously filed a statement on Schedule 13G to report the acquisition which is the subject of this Schedule 13D, and is filing this schedule because of Rule 13d-1(e), 13d-1(f) or 13d-1(g), check the following box. ☐

Note:  Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See Rule 13d-7 for other parties to whom copies are to be sent.

*The remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

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CUSIP No. G01767105

Page 2 of 6 Pages

This Amendment No. 4 to Schedule 13D (“Amendment No. 4”) relates to ordinary shares, par value $0.01 per share (“Common Stock” and, such shares, the “Shares”), issued by Alkermes Public Limited Company, a company incorporated under the laws of Ireland (the “Issuer”), and amends the initial statement on Schedule 13D filed with the Securities and Exchange Commission (the “SEC”) on May 10, 2021 (the “Initial Schedule 13D”), as amended by Amendment No. 1 to Schedule 13D filed on May 27, 2021 (“Amendment No. 1”), Amendment No. 2 to Schedule 13D filed on September 10, 2021 (“Amendment No. 2”) and Amendment No. 3 to Schedule 13D filed on November 19, 2021 (“Amendment No. 3” and together with the Initial Schedule 13D, Amendment No. 1 and Amendment No. 2, the “Schedule 13D”), on behalf of the Reporting Persons, to furnish the additional information set forth herein. All capitalized terms contained herein but not otherwise defined shall have the meanings ascribed to such terms in the Schedule 13D.

Item 3.  Source or Amount of Funds or Other Consideration. Item 3 of the Schedule 13D is hereby amended to include the following:

The Reporting Persons may be deemed to be the beneficial owner of, in the aggregate, 14,040,000 Shares. The aggregate purchase price of the Shares purchased by the Reporting Persons reported in this Amendment 4 is approximately $18,121,054. The source of funding for these purchases was the general working capital of the respective purchasers.

Item 4.  Purpose of Transaction. Item 4 of the Schedule 13D is hereby amended to include the following:

On January 7, 2022, the Sarissa Funds filed a notice with the Issuer indicating its intention to nominate directors for election to the Board at the Issuer’s 2022 annual general meeting of shareholders. The Reporting Persons have had discussions with the Issuer and other interested parties regarding Board composition, governance, operations and other matters and intend to continue these discussions.

Item 5.  Interest in Securities of the Issuer. Items 5 (a) and (c) of the Schedule 13D are hereby amended and restated as follows:

(a) The Reporting Persons may be deemed to beneficially own, in the aggregate, 14,040,000 Shares representing approximately 8.68% of the outstanding Shares, based upon the 161,705,367 Shares outstanding as of October 22, 2021, as set forth in the Form 10-Q of the Issuer filed with the U.S. Securities and Exchange Commission on October 27, 2021.

(c)

On November 24, 2021, the Sarissa Funds acquired 125,000 Shares at $22.90 per Share, in open market transactions, for an aggregate purchase price of $2,866,388.

On November 26, 2021, the Sarissa Funds acquired 75,000 Shares at $22.49 per Share, in open market transactions, for an aggregate purchase price of $1,689,105.

On November 29, 2021, the Sarissa Funds acquired 125,000 Shares at $22.47 per Share, in open market transactions, for an aggregate purchase price of $2,812,475.

On November 30, 2021, the Sarissa Funds acquired 200,000 Shares at $22.05 per Share, in open market transactions, for an aggregate purchase price of $4,416,520.

On December 1, 2021, the Sarissa Funds acquired 75,000 Shares at $21.71 per Share, in open market transactions, for an aggregate purchase price of $1,630,260.

On December 2, 2021, the Sarissa Funds acquired 1,000 and 55,000 Shares at $21.77 and $21.99 per Share respectively, in open market transactions, for an aggregate purchase price of $1,232,739.

On December 3, 2021, the Sarissa Funds acquired 150,000 Shares at $20.03 per Share, in open market transactions, for an aggregate purchase price of $3,009,150.

On December 6, 2021, the Sarissa Funds acquired 21,000 Shares at $22.09 per Share, in open market transactions, for an aggregate purchase price of $464,417.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, the undersigned certifies that the information set forth in this statement is true, complete and correct.

Dated:  January 10, 2022

SARISSA CAPITAL MANAGEMENT LP

By:	/s/ Mark DiPaolo
	Name: Mark DiPaolo
	Title: Senior Partner, General Counsel

/s/Alexander J. Denner________________________
Alexander J. Denner