SAR 6 - ALKERMES PLC

Lodge with the Stock Exchange (which may publicise) and with the Panel.A copy must also be sent to the company the voting securities of which (or the rights over the voting securities of which) are acquired.

Date of disclosure 08-05-2026

DISCLOSURE UNDER RULE 6 OF THE IRISH TAKEOVER PANEL ACT, 1997, SUBSTANTIAL ACQUISITION RULES, 2007 ("SARs")

Date of Acquisition ...07-05-2026

Acquisition in ALKERMES PLC (name of company)

(3)   Party making disclosure: BlackRock, Inc.

(4)  (a) Name of person acquiring securities or rights over securities: BlackRock, Inc.

and if different, beneficial owner

(b) Names of any other persons acting in concert (see SAR 3)

Signed, for and on behalf of the party named in (3) above

(Also print name of signatory) Jana Blumenstein

Telephone and extension number: +44 0207 743 3650

Note 1. Under SAR 3, the holdings of and acquisitions by persons acting in concert must be aggregated and treated as a holding of or acquisition by one person. SAR 8(b) requires persons who must aggregate holdings to disclose certain disposals.

Note 2. "Stock Exchange": see definition in Rule 2.1(a) of Part A of the Takeover Rules.

For full details of the SARs disclosure requirements, see Rules 4, 6 and 8(b) of the SARs. If in doubt, consult the Panel.