A Manhattan federal court has sided with Novartis in a lawsuit accusing the pharmaceutical giant of using a patent listing to keep cheaper generic versions of its heart-failure drug Entresto off the U.S. market for longer.
U.S. District Judge Lewis Liman dismissed a proposed class action brought on behalf of purchasers of Entresto, rejecting claims that Novartis improperly listed a patent in the Food and Drug Administration’s Orange Book to extend the drug’s market protection.
The lawsuit was filed by the Iron Workers Local 580 Insurance Fund on behalf of people and organizations that purchased Entresto. It alleged that Novartis’s patent listing unlawfully postponed generic competition and forced buyers to continue paying higher prices.
According to the complaint, the delay lasted at least six months, a period during which Novartis generated more than $2 billion in U.S. sales of Entresto.
At the heart of the dispute was whether the patent listed by Novartis actually covered Entresto itself. The purchasers argued that the patent applied to individual components of the medicine but did not cover the particular combination in which those ingredients are used in Entresto.
Judge Liman rejected that interpretation, agreeing with Novartis that the patent was properly included in the Orange Book.
The ruling comes as Entresto’s long-running dominance in the U.S. market has begun to weaken following the expiration of its patents and the arrival of generic competitors.
Entresto remains Novartis’s top-selling medicine, but the company’s sales from the drug fell 42% to $1.31 billion during the first quarter of 2026 after generic versions entered the U.S. market.
Entresto has been a major contributor to Novartis’s business, accounting for about 14% of the company’s sales in the previous year.
The case, *Iron Workers Local 580 Insurance Fund v. Novartis Pharmaceuticals Corp.*, was heard in the U.S. District Court for the Southern District of New York.
