The U.S. Court of Appeals for the Third Circuit on Monday blocked the Federal Trade Commission from reviving a lawsuit accusing a Shire unit years ago of using a web of sham regulatory filings to protect its top-selling gastrointestinal drug.

In a precedential ruling, a three-judge panel of the appeals court upheld a Delaware district court ruling, which found that the FTC’s 2017 suit came too late under Section 13(b) of the Federal Trade Commission Act, which requires the agency to show that a defendant “is violating, or is about to violate,” the law with excessive filings meant to improperly suppress generic competition.