<SEC-DOCUMENT>0001127602-24-028884.txt : 20241209
<SEC-HEADER>0001127602-24-028884.hdr.sgml : 20241209
<ACCEPTANCE-DATETIME>20241209205158
ACCESSION NUMBER:		0001127602-24-028884
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20241208
FILED AS OF DATE:		20241209
DATE AS OF CHANGE:		20241209

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			LAURENCIN CATO T
		CENTRAL INDEX KEY:			0001444810
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-35299
		FILM NUMBER:		241536871

	MAIL ADDRESS:	
		STREET 1:		C/O UNIVERSITY OF CONNECTICUT
		STREET 2:		263 FARMINGTON AVENUE
		CITY:			FARMINGTON
		STATE:			CT
		ZIP:			06030-3800

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Alkermes plc.
		CENTRAL INDEX KEY:			0001520262
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		ORGANIZATION NAME:           	03 Life Sciences
		IRS NUMBER:				981007018
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		CONNAUGHT HOUSE
		STREET 2:		1 BURLINGTON ROAD
		CITY:			DUBLIN 4
		STATE:			L2
		ZIP:			00000
		BUSINESS PHONE:		00-353-1-772-8000

	MAIL ADDRESS:	
		STREET 1:		CONNAUGHT HOUSE
		STREET 2:		1 BURLINGTON ROAD
		CITY:			DUBLIN 4
		STATE:			L2
		ZIP:			00000

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	ANTLER SCIENCE TWO PLC
		DATE OF NAME CHANGE:	20110804

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Antler Science Two Ltd
		DATE OF NAME CHANGE:	20110509
</SEC-HEADER>
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<SEQUENCE>1
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    <periodOfReport>2024-12-08</periodOfReport>

    <issuer>
        <issuerCik>0001520262</issuerCik>
        <issuerName>Alkermes plc.</issuerName>
        <issuerTradingSymbol>ALKS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001444810</rptOwnerCik>
            <rptOwnerName>LAURENCIN CATO T</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>CONNAUGHT HOUSE</rptOwnerStreet1>
            <rptOwnerStreet2>1 BURLINGTON ROAD</rptOwnerStreet2>
            <rptOwnerCity>DUBLIN</rptOwnerCity>
            <rptOwnerState></rptOwnerState>
            <rptOwnerZipCode>4 Ireland</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>1</aff10b5One>

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                <value>Ordinary Shares</value>
            </securityTitle>
            <transactionDate>
                <value>2024-12-08</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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            <transactionAmounts>
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                </transactionShares>
                <transactionPricePerShare>
                    <value>31.46</value>
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                <transactionAcquiredDisposedCode>
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                    <value>D</value>
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        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Ordinary Shares</value>
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            <transactionDate>
                <value>2024-12-09</value>
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            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
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            <transactionAmounts>
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                <transactionPricePerShare>
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        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Restricted Stock Unit Award</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2024-12-08</value>
            </transactionDate>
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                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
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                    <value>4163</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F4"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F4"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Ordinary Shares</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>4163</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
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                <directOrIndirectOwnership>
                    <value>D</value>
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        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Non Qualified Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>22.52</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2024-12-09</value>
            </transactionDate>
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                <transactionAcquiredDisposedCode>
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            <exerciseDate>
                <footnoteId id="F5"/>
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            <expirationDate>
                <value>2031-12-08</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
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                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>2691</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
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                <sharesOwnedFollowingTransaction>
                    <value>16142</value>
                </sharesOwnedFollowingTransaction>
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                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
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        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Each restricted stock unit represents a contingent right to receive one ordinary share.</footnote>
        <footnote id="F2">This option exercise was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on 2/26/2023.</footnote>
        <footnote id="F3">This sale was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on 2/26/2023.</footnote>
        <footnote id="F4">This award is fully vested in accordance with its terms.</footnote>
        <footnote id="F5">These options are fully vested in accordance with their terms.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Shantale Greenson, attorney-in-fact for Cato T. Laurencin</signatureName>
        <signatureDate>2024-12-09</signatureDate>
    </ownerSignature>
</ownershipDocument>
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</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
