December 12, 2022

Horizon Therapeutics and Amgen have reached agreement on the terms of a cash offer for the Company by Pillartree, a newly formed private limited company wholly owned by Amgen, which is unanimously recommended by the Company Board and pursuant to which Acquirer Sub will acquire the entire issued and to be issued ordinary share capital of the Company. Under the terms of the Acquisition, each Company Shareholder at the Scheme Record Time will be entitled to receive $116.50 for each Company Share in cash.

The Acquisition represents:

a premium of approximately 47.9% to the closing price of $78.76 per Company Share on November 29, 2022 (being the last closing price per Company Share prior to the Company’s issuance of an announcement of a possible offer under Rule 2.4 of the Irish Takeover Rules); and

a premium of approximately 19.7% to the closing price of $97.29 per Company Share on December 9, 2022.

The Acquisition values the entire issued and to be issued ordinary share capital of the Company at approximately $27.8 billion on a fully diluted basis and implies an enterprise value of approximately $28.3 billion.

Amgen has entered into a Bridge Credit Agreement, dated December 12, 2022, for an aggregate amount of $28.5 billion, by and among Amgen, Citibank N.A., as administrative agent, Bank of America, N.A., as syndication agent, and Citibank, N.A. and Bank of America, N.A. as lead arrangers and book runners, and the other banks from time to time party thereto to finance, together with Amgen’s own cash resources, the Acquisition.

Commenting on today’s announcement, Tim Walbert, chairman, president and chief executive officer of the Company said: “In nearly 15 years, we have built one of the fastest growing and most respected companies in the biotechnology industry from the ground up. We have accomplished a tremendous amount for patients, their families and our customers, and created significant value for shareholders. These accomplishments are all rooted in our employees’ deep commitment, dedication and personal passion for those impacted by rare, autoimmune and severe inflammatory diseases. Amgen is aligned with that commitment and passion and will continue to maximise the value of the current portfolio and pipeline and accelerate the ability to reach more patients globally.”

Commenting on today’s announcement, Robert A. Bradway, chairman and chief executive officer of Amgen said: “The acquisition of Horizon is a compelling opportunity for Amgen and one that is consistent with our strategy of delivering long-term growth by providing innovative medicines that address the needs of patients who suffer from serious diseases. Amgen’s decades of leadership in inflammation and nephrology, combined with our global presence and world-class biologics capabilities, will enable us to reach many more patients with first-in-class medicines like TEPEZZA, KRYSTEXXA and UPLIZNA. Additionally, the potential new medicines in Horizon’s pipeline strongly complement our own R&D portfolio. The acquisition of Horizon will drive growth in Amgen’s revenue and non-GAAP EPS and is expected to be accretive from 2024.”