Horizon Therapeutics plc Announces Closing of Public Offering of Ordinary Shares and Full Exercise of Underwriters' Option to Purchase Additional Ordinary Shares

Horizon Therapeutics plc (Nasdaq: HZNP) today announced the closing of its underwritten public offering of 13,570,000 of its ordinary shares at a price to the public of $71.00 per share. This includes the exercise in full by the underwriters of their option to purchase up to 1,770,000 additional ordinary shares. The net proceeds to the Company from this offering are expected to be approximately $919.3 million, after deducting underwriting discounts and other estimated offering expenses payable by the Company. Following the closing of the offering, there were 220,346,699 ordinary shares of the Company outstanding as of August 11, 2020.

Citigroup, Morgan Stanley, J.P. Morgan, Piper Sandler and Stifel acted as joint book-running managers for the offering. Cowen acted as a financial advisor to the Company for the offering.

A registration statement relating to the ordinary shares described above was previously filed with and became effective by rule of the Securities and Exchange Commission ("SEC"). A final prospectus supplement and accompanying prospectus related to the offering was filed with the SEC and is available on the SEC's website located at http://www.sec.gov. Copies of the final prospectus supplement and accompanying prospectus may be obtained on the SEC's website or by contacting Citigroup Global Markets Inc., c/o Broadridge Financial Solutions, 1155 Long Island Avenue, Edgewood, NY 11717 or by phone at 800-831-9146; Morgan Stanley & Co. LLC, 180 Varick Street, 2nd Floor, New York, NY 10014, Attention: Prospectus Department or by email at [email protected]; J.P. Morgan Securities LLC, c/o Broadridge Financial Solutions, 1155 Long Island Avenue, Edgewood, NY 11717, by email at [email protected] or by phone at 866-803-9204; Piper Sandler & Co., Attention: Prospectus Department, 800 Nicollet Mall, J12S03, Minneapolis, MN 55402, by email at [email protected] or by phone at 800-747-3924; or Stifel, Nicolaus & Company, Incorporated, Attention: Prospectus Department, One Montgomery Street, Suite 3700, San Francisco, CA 94104, by email at [email protected] or by phone at 415-364-2720.

This press release shall not constitute an offer to sell or the solicitation of an offer to buy, nor shall there be any sale of, the shares in any state or other jurisdiction which such offer, solicitation or sale would be unlawful prior to the registration or qualification under the securities laws of any such state or other jurisdiction.

About Horizon Therapeutics plc

Horizon is focused on researching, developing and commercializing medicines that address critical needs for people impacted by rare and rheumatic diseases. Our pipeline is purposeful: we apply scientific expertise and courage to bring clinically meaningful therapies to patients. We believe science and compassion must work together to transform lives.