Regeneron Hits Amgen With Antitrust Suit Over Cholesterol Drugs

Regeneron Pharmaceuticals Inc. opened a new front Friday in its long-running fight with Amgen Inc., launching federal antitrust litigation in Delaware over claims that Amgen uses illegal tactics to shield its cholesterol drug Repatha from competition with Regeneron’s Praluent.

The lawsuit accuses Amgen of responding to a series of patent losses by pivoting to an illegal “bundling” scheme aimed at coercing key payment intermediaries by conditioning “entirely unrelated” rebates involving must-have blockbuster drugs on their choice to cover Repatha rather than Praluent.

The pressure on those intermediaries—pharmacy benefit managers that administer prescription networks for health plans—has “made it economically ...