Mallinckrodt Loses Ruling in U.S Lawsuit Over Acthar Gel

Mallinckrodt Plc failed to quash U.S. claims that the drugmaker owes hundreds of millions of dollars in rebates from sales of its most-prescribed medicine, Acthar Gel.

U.S. District Judge Thomas Hogan in Washington on Friday rejected the company’s claim that the Centers for Medicare & Medicaid Services had improperly tried to collect past rebates. He ordered the case closed in the government’s favor in an order posted on the court’s electronic docket. The judge’s opinion was sealed, so his reasoning wasn’t immediately available.

The decision adds to the legal woes for the drugmaker, which agreed to pay $1.6 billion to ...