Entresto is a medication used to treat heart failure. According to Drug Patent Watch [1], the patent for Entresto is set to expire on June 16, 2025. However, Novartis, the manufacturer of Entresto, has been facing legal battles against generic drug makers who are seeking to launch their own versions of the drug. Novartis filed a lawsuit against a number of these companies in 2019, alleging patent infringement [2]. In response, some of these companies have challenged the validity of Novartis' patents. In April 2021, Novartis appealed to the FDA to block the approval of generic versions of Entresto, but this appeal was rejected [3]. Despite these legal challenges, the current expiration date for the patent remains June 16, 2025.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/ENTRESTO
[2] https://www.fiercepharma.com/pharma/novartis-hit-entresto-patent-suit-amid-legal-fights-against-generic-makers
[3] https://www.fiercepharma.com/pharma/novartis-takes-entresto-generic-fight-fda-again-after-similar-appeal-flopped-april