Name of person dealing (Note 1)

The Vanguard Group, Inc.

Company dealt in

Horizon Therapeutics plc

Class of relevant security to which the dealings being disclosed relate (Note 2)

$0.0001 ordinary shares

Date of dealing

30 November 2022

Long

Short

Numbers

(%)

Numbers

(%)

(1) Relevant securities

21,586,362

9.52%

(2) Derivatives (other than options)

(3) Options and agreements to purchase/sell

Total

21,586,362

9.52%

Class of relevant security:

Long

Short

Numbers

(%)

Numbers

(%)

(1) Relevant securities

(2) Derivatives (other than options)

(3) Options and agreements to purchase/sell

Total

Purchase/sale

Number of relevant securities

Price per unit (Note 5)

Purchase

3,880

100.29 USD

Sale

232

100.29 USD

Product name,

e.g. CFD

Nature of transaction

(Note 6)

Number of relevant securities

(Note 7)

Price per unit

(Note 5)

Not Applicable

Product name,

e.g. call option

Writing, selling, purchasing, varying etc.

Number of securities to which the option relates (Note 7)

Exercise price

Type, e.g. American, European etc.

Expiry date

Option money paid/received per unit (Note 5)

Not Applicable

Product name,

e.g. call option

Number of securities

Exercise price per unit (Note 5)

Not Applicable

Nature of transaction

(Note 8)

Details

Price per unit

(if applicable) (Note 5)

Not Applicable

Full details of any agreement, arrangement or understanding between the person disclosing and any other person relating to the voting rights of any relevant securities under any option referred to on this form or relating to the voting rights or future acquisition or disposal of any relevant securities to which any derivative referred to on this form is referenced. If none, this should be stated.

Date of disclosure

02 December 2022

Contact name

Shawn Acker

Telephone number

001-610-669-8989

If a connected EFM, name of offeree/offeror with which connected

If a connected EFM, state nature of connection (Note 10)