Amgen Inc.’s $27.8 billion deal to buy Horizon Therapeutics Plc, the largest in the biotechnology company’s history, will be challenged by federal regulators on the grounds it would hamper innovation and drug development, according to a person familiar with the matter.
The Federal Trade Commission is expected to file a lawsuit to block the purchase on Tuesday, the person said, asking not to be identified discussing private information. A suit would mark the first time in more than a decade that the FTC has sought to stop a pharmaceutical deal outright.
Horizon shares plunged 17% at 9:34 a.m. ...
