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

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No.1)*

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).

1	NAME OF REPORTING PERSON OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Sarissa Capital Management LP
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP			(a)  ☐ (b)  ☐
3	SEC USE ONLY
4	SOURCE OF FUNDS WC
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e)			☐
6	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER 0
		8	SHARED VOTING POWER 11,245,000
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 11,245,000
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 11,245,000
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES:			☐
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 7.01%
14	TYPE OF REPORTING PERSON   PN

1	NAME OF REPORTING PERSON OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Alexander J. Denner, Ph.D.
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP			(a)  ☐ (b)  ☐
3	SEC USE ONLY
4	SOURCE OF FUNDS WC
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) OR 2(e)			☐
6	CITIZENSHIP OR PLACE OF ORGANIZATION United States
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER 0
		8	SHARED VOTING POWER 11,245,000
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 11,245,000
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 11,245,000
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES:			☐
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 7.01%
14	TYPE OF REPORTING PERSON   IN

CUSIP No. G01767105

Page 4 of 5 Pages

This statement constitutes Amendment No.1 to Schedule 13D (“Amendment No.1”) relates to shares of 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”) on behalf of the Reporting Persons to furnish the additional information set forth herein. The address of the principal executive offices of the Issuer is Connaught House, 1 Burlington Road, Dublin 4, Ireland D04 C5Y6. All capitalized items contained herein but not otherwise defined shall have the meanings ascribed to such terms in the Initial Schedule 13D.

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

The Reporting Persons may be deemed to be the beneficial owner of, in the aggregate, 11,245,000 Shares. The aggregate purchase price of the Shares purchased by the Reporting Persons reported in this Amendment No.1 are approximately $39,190,648. The source of funding for these purchases was the general working capital of the respective purchasers.

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

(a) The Reporting Persons may be deemed to beneficially own, in the aggregate, 11,245,000 Shares representing approximately 7.01% of the outstanding Shares, based upon the 160,451,949 Shares outstanding as of April 23, 2021, as set forth in the Form 10-K/A of the Issuer filed with the U.S. Securities and Exchange Commission on April 29, 2021.

(b) For purposes of this Schedule 13D:

All of the Shares for which Sarissa Capital and Dr. Denner may be deemed to be have a beneficial ownership are held directly by either Sarissa Capital or the Sarissa Funds for which Sarissa Capital serves as the investment advisor. Sarissa Capital, as the investment advisor to the Sarissa Funds, may be deemed to have the shared power to vote or direct the vote of (and the shared power to dispose or direct the disposition of) the 11,245,000 Shares held directly by the Sarissa Funds. By virtue of his position as the Chief Investment Officer of Sarissa Capital and by virtue of his control of the ultimate general partner of Sarissa Capital, Dr. Denner may be deemed to have the shared power to vote or direct the vote of (and the shared power to dispose or direct the disposition of) the 11,245,000 held directly by the Sarissa Funds.

(c)

On May 24, 2021, the Sarissa Funds acquired 1,000,000 Shares at $22.31 per Share, in open market transactions, for an aggregate purchase price of $22,336,100.

On May 25, 2021, the Sarissa Funds acquired 179,000 and 596,000 Shares at $21.61 and $21.75 per Share respectively, in open market transactions, for an aggregate purchase price of $16,854,547.40.

CUSIP No. G01767105

Page 5 of 5 Pages

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:  May 27, 2021

SARISSA CAPITAL MANAGEMENT LP

/s/Alexander J. Denner________________________
Alexander J. Denner