Plaintiff states  joined the Federal Trade Commission’s suit against Amgen’s planned $28 billion purchase of Horizon Therapeutics. The plaintiffs sought a temporary restraining order and preliminary injunction blocking Amgen Inc. and its subsidiaries from completing the proposed acquisition. Horizon Therapeutics PLC makes the only U.S. FDA-approved treatment for thyroid eye disease, Tepezza, and the only FDA-approved treatment for chronic refractory gout, Krystexxa, The plaintiffs allege Amgen could use rebates on its existing portfolio of drugs to pressure insurance companies and pharmacy benefits managers into favoring Tepezza and Krystexxa after competitors enter the market.