The FTC filed a lawsuit requesting a temporary restraining order and preliminary injunction to block Amgen Inc. from acquiring Horizon Therapeutics. Amgen agreed to purchase Horizon on December 11, 2022 for an approximate value of $28 billion. The FTC’s contention to the acquisition focuses on two of Horizon’s products, Tepezza and Krystexxa, because neither of those treatments have any competition in the pharmaceutical marketplace. The FTC fears that the transaction would allow Amgen to significantly increase their leverage in negotiations with pharmacy benefit managers (PBM) and payers as well as decrease competition and stymie innovation.  

The court granted the FTC’s temporary restraining order and preliminary injunction to block the acquisition until October 31, 2023 or two days following the court’s ruling on the preliminary injunction.