Amgen acquires Horizon Therapeutics (2022–2023)
Amgen agreed in December 2022 to buy Horizon for $27.8 billion, paying a premium for Tepezza, the leading thyroid eye disease drug, and Krystexxa for gout. The Federal Trade Commission sued to block the deal in May 2023, arguing Amgen could use rebate contracts to keep rivals out. The two sides settled in September 2023, and Amgen closed the deal the next month.
Amgen closed the acquisition after agreeing to a consent order restricting how it used rebate contracts.
Tepezza became a top product for Amgen, and the FTC's challenge signaled closer antitrust scrutiny of pharma M&A.
Tepezza is the existing standard of care for thyroid eye disease, the condition Merida's MER511 would challenge. The deal also shows pharma acquisitions can draw antitrust scrutiny even after approval.
