    <SEC-DOCUMENT>0000950170-25-051657-index.html : 20250407
    <SEC-HEADER>0000950170-25-051657.hdr.sgml : 20250407
    <ACCEPTANCE-DATETIME>20250407165851
    ACCESSION NUMBER:		0000950170-25-051657
    CONFORMED SUBMISSION TYPE:	ARS
    PUBLIC DOCUMENT COUNT:		1
    CONFORMED PERIOD OF REPORT:	20241231
    FILED AS OF DATE:		20250407
    DATE AS OF CHANGE:		20250407
    EFFECTIVENESS DATE:		20250407

    FILER:

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

    	FILING VALUES:
    		FORM TYPE:		ARS
    		SEC ACT:		1934 Act
    		SEC FILE NUMBER:	001-35299
    		FILM NUMBER:		25818848

    	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>
    <DOCUMENT>
    <TYPE>ARS
    <SEQUENCE>1
    <FILENAME>alks_2025_ars.pdf
    <DESCRIPTION>ARS
    <TEXT>
    Document 1 - file: alks_2025_ars.pdf

    </DOCUMENT>
    </SEC-DOCUMENT>