Patent Showdown: Federal Circuit Freezes MSN’s Entresto Launch Amid Novartis Battle

The underlying dispute centers on Novartis' U.S. Patent No. 8,101,659, which covers the use of sacubitril/valsartan (sold under the brand name Entresto) for treating heart failure with reduced ejection fraction (HFrEF). In a July 11 ruling, the U.S. District Court for the District of Delaware found that MSN's proposed generic product would not infringe the ‘659 patent. The ruling followed years of litigation in which Novartis asserted that generic challengers would infringe its intellectual property rights.

Entresto is one of Novartis’ most profitable drugs, generating over $7.8 billion globally in 2024, with more than $3 billion from U.S. sales alone. A generic entry could drastically undercut those revenues, providing a lower-cost alternative to patients but dealing a blow to Novartis' bottom line.

This is not the first time the Federal Circuit has intervened in this battle. In January 2025, the court granted Novartis a temporary, one-week stay of the lower court’s ruling, allowing time to consider the appeal. The latest stay could signal a willingness to further delay generic competition while the appellate court examines the merits of Novartis’ claims.

The decision also underscores the broader tension in the pharmaceutical industry over balancing innovation and access. Innovator companies argue that patent protections are critical to incentivizing costly research and development, while generics contend that patents are often stretched beyond their rightful scope to delay competition and keep prices high.

Industry experts say the outcome of the appeal could have far-reaching implications not only for Novartis and MSN but also for other generic drugmakers watching closely. Several other companies, including Zydus, Torrent, and Lupin, are also seeking to market their own versions of Entresto and may be impacted by the precedent this case sets.