Novartis loses initial bid to block generic of best-selling heart drug

By Blake Brittain

Aug 12 (Reuters) - Novartis failed to convince a Delaware federal court to block generic drugmaker MSN Pharmaceuticals from launching its own version of Novartis' blockbuster heart-failure drug Entresto, according to a court decision issued on Monday.

U.S. District Judge Richard Andrews ruled that Novartis' chance of winning its patent-infringement lawsuit challenging the generic was too low to justify halting MSN's launch. However, he temporarily ordered MSN not to sell the drug while Novartis appeals to the U.S. Court of Appeals for the Federal Circuit.

Entresto is Switzerland-based Novartis' best-selling drug, earning the company more than $6 billion in revenue last year. MSN's version of Entresto was approved by the U.S. Food and Drug Administration last month and would be the first U.S. generic of the drug.

Spokespeople for Novartis and MSN did not immediately respond to requests for comment on the decision.

Novartis sued MSN and others seeking to launch Entresto generics in 2022 for infringing a patent that expires in 2026. It asked the court on Aug. 2 for a preliminary injunction blocking MSN from launching its generic, which was approved by the FDA on July 24.

Andrews ruled on Monday that Novartis was not likely enough to win on its infringement claims to justify the injunction. The judge also rejected Novartis' argument that a ruling against the company would cause "irreparable harm" by triggering a wave of generic Entresto launches by other drugmakers.

Andrews placed a three-day hold on the case while Novartis appeals to the Federal Circuit.

Novartis has separately asked a Washington, D.C. district court to block MSN's launch as part of a challenge to the FDA's decision to approve the generic. The Washington court has not yet ruled on Novartis' request. (Reporting by Blake Brittain in Washington; Editing by Andrea Ricci)