Context: Entresto, a Novartis drug used to treat chronic heart failure, first approved in 2015, will be among the first high-spend drugs subject to government-negotiated pricing for Medicare patients starting in 2026 under the Inflation Reduction Act. The drug brought in over $7.8 billion in sales for Novartis last year, and, in an effort to defend its corner of the market and jump ahead of the impending threat of generics, Novartis sued the FDA over its green light of MSN’s generic Entresto, alleging that it “inappropriately rewrites Entresto’s approved indication” and omits key safety data (August 1, 2024 Fierce Pharma article). The company also sued MSN, alleging infringement of two of its Entresto-related patents in the District of Delaware. In one case, Novartis has reportedly filed a letter urging the court to speed up its decision-making process (June 6, 2025 Fierce Pharma article: the redacted letter is attached below box). In the other case, MSN filed a letter (copy also below box) responding to a request for injunctive relief by Novartis on June 10. In its letter, MSN accused Novartis of “essentially re-packag[ing] its post-trial brief.”
What’s new: MSN and Novartis have settled part of their Entresto patent fight in the U.S. (court order below). This means they are no longer litigating over this patent: U.S. Patent No. 8,101,659 (“Methods of treatment and pharmaceutical composition”).
Direct impact: That patent, initially already expired, was granted a period of pediatric exclusivity, extending its life to July 15, 2025 (in part due to its Orange Book listing). While it is settled, it will now depend on the case over the second patent when MSN can enter the market.
Wider ramifications: The second patent-in-suit, listed below, is due to expire in November 2026:
- (U.S. Patent No. 11,096,918 (“Amorphous solid form of compounds containing S—N-valeryl-N-{[2′-(1H-tetrazole-5-yl)-biphenyl-4-yl]-methyl}-valine and (2R,4S)-5-biphenyl-4-yl-4-(3-carboxy-propionylamino)-2-methyl-pentanoic acid ethyl ester moieties and sodium cations”)
If Novartis is successful in its injunctive relief request, it could further reset MSN’s Entresto drug launch to after that expiration date.
Below is the order confirming the settlement of the dispute over the second patent:
Here is a breakdown of the overall case to date:
- October 2022: Novartis asserted its two patents against MSN in the District of Delaware, after MSN had submitted an Abbreviated New Drug Application (ANDA) for a generic version of Entresto. During claim construction, MSN argued the claims required valsartan and sacubitril to be “two separate components”.
- July 2024: Novartis then requested a preliminary injunction to block MSN’s launch. Judge Richard Andrews of the United States District Court for the District of Delaware denied that request, finding Novartis unlikely to succeed on the merits and that they didn’t show irreparable harm.
- January 2025: The Federal Circuit decided on the ‘659 patent (PDF).
- April 2025: The Delaware court ruled in Novartis’s favor, ordering the FDA to reset the effective approval date of MSN’s application to “no earlier than July 16, 2025”. MSN then sought relief from that judgment, arguing that the court’s opinion had “significantly changed the scope of what the patent [at issue] claims”, and therefore it no longer infringes the patent asserted.
- May 23, 2025: On appeal, the Federal Circuit reversed that decision. It ruled: “Because MSN’s motion has failed to show a sufficient likelihood of success regarding its challenges to the district court’s decision denying relief from the final judgment, we deny the motion for a stay. We also deny the motion to expedite the appeals.”
- June 3, 2025: Novartis filed a letter reportedly requesting the Delaware court to issue a final decision and verdict on the case before July 15, effectively further resetting the effective approval date of MSN’s generic drug until after November 9, 2026. Here is a (redacted) copy of the letter Novartis issued last week:
- June 10, 2025: MSN responded to that letter, claiming Novartis “essentially re-packaged its post-trial brief.” Here is that letter:
Counsel
Novartis is being represented by Morrison & Foerster’s Deanne Maynard, Seth W. Lloyd, and Zach ZhenHe Tan, as well as Venable LLP’s Christina A. L. Schwarz, and Nicolas Kalla. Meanwhile, MSN is being represented by Stamoulis & Weinblatt’s Richard Charles Weinblatt, as well as RMMS Legal’s William A. Rakoczy, Deanne M. Mazzochi, Kevin E. Warner, and Daignault Iyer LLP’s Ronald M. Daignault, and Richard Juang.