© Reuters. FILE PHOTO: An Amgen sign is seen at the company’s office in South San Francisco, California October 21, 2013. The biopharmaceutical company reports earnings on Tuesday. REUTERS/Robert Galbraith/File Photo
(Reuters) – Amgen Inc (NASDAQ:) said on Monday it would buy rare disease drugmaker Horizon Therapeutics (NASDAQ:) Plc for $26.40 billion in its biggest deal yet, giving the biotech company access to blockbuster thyroid eye disease treatment Tepezza.
Amgen will pay $116.50 in cash for each Horizon share held, or a premium of nearly 20% to the stock’s last close.
The offer values Horizon at $28.3 billion, including debt.
A deal will add several approved drugs to the company’s portfolio including Krystexxa used for the treatment of gout that is not controlled by other medicines.
The acquisition could help Amgen counter the impact from rising competition for its top-selling arthritis drug, Enbrel, from newer branded treatments and expected expiry of patents for the therapy in 2029.