Novartis v. Mylan: ENTRESTO® Patent Dispute Dismissed After 693 Days
Novartis Pharmaceuticals Corporation filed suit against Mylan Pharmaceuticals Inc. in the Delaware District Court alleging infringement of US11058667B2, a patent covering its blockbuster ENTRESTO® heart failure tablets. The case was dismissed after nearly two years, alongside parallel proceedings in West Virginia and at the Federal Circuit.
ENTRESTO® patent battle dismissed after multi-forum standoff
Novartis Pharmaceuticals Corporation filed this infringement action against Mylan Pharmaceuticals Inc. on April 5, 2022 in the U.S. District Court for the District of Delaware before Judge Richard G. Andrews. The asserted patent, US11058667B2, covers ENTRESTO® tablets — Novartis’s sacubitril/valsartan combination therapy for heart failure — in three dose strengths: 24 mg/26 mg, 49 mg/51 mg, and 97 mg/103 mg. The suit is consistent with Novartis’s broader strategy of enforcing its ENTRESTO® patent portfolio against generic filers seeking ANDA approval.
The Delaware case was not litigated in isolation. Court filings reference a parallel action in the U.S. District Court for the Northern District of West Virginia (No. 1:19-cv-201-TSK) and a consolidated Federal Circuit appeal (No. 23-2260, consolidated with Lead Appeal No. 23-2218). In January 2024, the parties jointly stipulated to a 75-day stay of the Delaware proceedings as they related to Mylan, citing ongoing activity expected to require time to resolve. The case was ultimately dismissed on February 27, 2024.
The 693-day duration and the structured stay agreed upon by both parties suggest the dismissal may have been tied to resolution of the broader multi-forum dispute rather than a standalone Delaware outcome. The specific terms of any resolution — whether a settlement, licence, or consent judgement in another forum — are not apparent from the Delaware public record. The Federal Circuit appeal and West Virginia proceeding represent additional touchpoints that may reveal the full commercial outcome for Mylan’s generic entry timeline.
Filing to dismissal in 693 days
693 days — nearly two years of active multi-forum litigation before dismissal
What the dismissal of this Delaware action means for both parties
Case dismissed — prejudice status unspecified in public record
The Delaware docket records the basis of termination as ‘Case Dismissed,’ but the public filing does not specify whether dismissal was with or without prejudice. This distinction is commercially significant: dismissal with prejudice bars Novartis from refiling the same claims in this court, while dismissal without prejudice preserves that right. Practitioners should review the full docket order to determine the operative prejudice status before drawing conclusions about Novartis’s enforcement options in Delaware.
Prejudice status: unconfirmedDelaware was one of three concurrent proceedings against Mylan
At the time of the January 2024 stay stipulation, Novartis and Mylan were simultaneously engaged in a West Virginia district court action (No. 1:19-cv-201-TSK) and a Federal Circuit appeal (No. 23-2260). The parties’ agreement to pause Delaware for 75 days to allow other proceedings to progress is a classic multi-forum coordination strategy. Dismissal of the Delaware case may reflect resolution achieved — or progress made — in one of those parallel venues rather than a standalone Delaware outcome.
Multi-forum coordination75-day mutual stay preceded dismissal — a meaningful signal
The January 2024 joint stipulation for a 75-day stay included a mutual non-aggression clause: neither party would act directly adverse to the other across any of the related actions during the stay. This type of agreement typically signals that settlement or licensing discussions are underway. The stay was set to expire April 8, 2024, yet the case closed February 27, 2024 — suggesting resolution was reached before the stay’s natural expiry.
Early resolution signalMylan’s ENTRESTO® generic entry timeline remains a key unknown
ENTRESTO® is one of the highest-revenue cardiovascular drugs globally. The dismissal of this Delaware action does not, on its face, confirm whether Mylan has secured a launch date, licence, or consent judgement. The outcome of the West Virginia proceedings and Federal Circuit appeal (No. 23-2260) will be determinative for Mylan’s ability to commercially launch a generic sacubitril/valsartan product. Competitors and payers tracking generic entry should monitor those parallel proceedings closely.
Generic entry: unresolvedFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | Novartis Pharmaceuticals Corporation | Company | Global pharmaceutical innovator — holder of US11058667B2 covering ENTRESTO® tabletsSearch in Eureka ↗ |
| Defendant | Mylan Pharmaceuticals, Inc. | Company | Generic pharmaceutical manufacturer and ANDA filer, subsidiary of Viatris Inc.Search in Eureka ↗ |
| Plaintiff counsel | Alexandra M. Joyce | Attorney | Counsel for Novartis Pharmaceuticals CorporationSearch in Eureka ↗ |
| Plaintiff counsel | Christina Schwarz | Attorney | Counsel for Novartis Pharmaceuticals CorporationSearch in Eureka ↗ |
| Plaintiff counsel | Christopher E. Loh | Attorney | Counsel for Novartis Pharmaceuticals CorporationSearch in Eureka ↗ |
| Plaintiff counsel | Daniel M. Silver | Attorney | Counsel for Novartis Pharmaceuticals CorporationSearch in Eureka ↗ |
| Plaintiff counsel | Jared L. Stringham | Attorney | Counsel for Novartis Pharmaceuticals CorporationSearch in Eureka ↗ |
| Plaintiff counsel | Melinda R. Roberts | Attorney | Counsel for Novartis Pharmaceuticals CorporationSearch in Eureka ↗ |
| Plaintiff counsel | Nicholas N. Kallas | Attorney | Counsel for Novartis Pharmaceuticals CorporationSearch in Eureka ↗ |
| Defendant counsel | David Ellis Moore | Attorney | Counsel for Mylan Pharmaceuticals, Inc.Search in Eureka ↗ |
| Defendant counsel | Robert L. Florence | Attorney | Counsel for Mylan Pharmaceuticals, Inc.Search in Eureka ↗ |
| Defendant counsel | Tasneem A. Dharamsi | Attorney | Counsel for Mylan Pharmaceuticals, Inc.Search in Eureka ↗ |
| Presiding judge | Judge Richard G. Andrews | Chief Judge | Delaware District Court — Chief JudgeSearch in Eureka ↗ |
Stipulation of dismissal — official text
The verdict record for this case is a joint stay stipulation rather than a merits ruling. The parties agreed to a 75-day standstill, with reciprocal obligations not to act adversely in any related forum. Critically, the stay applied only to Mylan — leaving Novartis free to continue pressing claims against other defendants. This asymmetric design suggests Novartis retained strategic flexibility while negotiations with Mylan proceeded, consistent with a bilateral resolution rather than a litigation defeat for either side.
US11058667B2 — ENTRESTO® Sacubitril/Valsartan Heart Failure Formulation
US11058667B2 (application number US15/572399) protects the formulation of ENTRESTO®, Novartis’s sacubitril/valsartan combination tablet indicated for heart failure with reduced ejection fraction. The patent covers three commercially marketed dose strengths: 24 mg/26 mg, 49 mg/51 mg, and 97 mg/103 mg. Sacubitril/valsartan represents a mechanistically novel dual-acting angiotensin receptor–neprilysin inhibitor (ARNI), and the formulation patents protecting its commercial presentation are a primary line of defence against generic competition.
ENTRESTO® generated multi-billion-dollar annual revenues for Novartis, making US11058667B2 one of the highest-stakes formulation patents in the cardiovascular space. For generic manufacturers, defeating or designing around this patent is a prerequisite to launching a competing sacubitril/valsartan product. The patent’s involvement in simultaneous Delaware and West Virginia proceedings, as well as a Federal Circuit appeal, reflects Novartis’s active multi-front enforcement posture and signals that the IP barrier around ENTRESTO® remains contested and commercially significant.
Should you run an FTO analysis against US11058667B2?
Any pharmaceutical company developing, formulating, or planning to commercialise a sacubitril/valsartan combination product in the United States should treat US11058667B2 as a high-priority FTO target. The patent has been actively enforced against at least one major generic filer across multiple federal courts simultaneously. Even where one case has closed, related proceedings at the Federal Circuit may produce claim construction guidance that reshapes the enforceability landscape for all potential entrants.
PatSnap Eureka’s FTO Search Agent can map the full claim scope of US11058667B2 against your product’s formulation parameters, surface related Novartis family members, and flag any inter partes review or post-grant proceedings that may have narrowed or invalidated specific claims. Continuous claim monitoring ensures your FTO remains current as Federal Circuit proceedings conclude — particularly given the consolidated appeal No. 23-2260 that may still be active.
Run a freedom-to-operate analysis on US11058667B2 to assess your product’s exposure
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What this case signals for the cardiovascular generic drug IP landscape
Novartis’s multi-forum enforcement strategy around ENTRESTO® sets a benchmark for how innovators defend blockbuster cardiovascular IP against ANDA challengers.
Multi-forum enforcement is Novartis’s playbook for ENTRESTO® defence
Running simultaneous actions in Delaware, West Virginia, and the Federal Circuit maximises litigation pressure on generic filers and creates procedural complexity that extends the effective market exclusivity window. Generic manufacturers planning ANDA challenges to ENTRESTO® should budget for protracted, multi-venue disputes rather than single-court resolution.
Mutual stay agreements often precede settlement — watch the Federal Circuit
The 75-day mutual stay with a non-aggression clause is a well-established pre-settlement procedural step in Hatch-Waxman litigation. The fact that the Delaware case closed before the stay expired suggests the parties reached agreement faster than anticipated. The Federal Circuit appeal (No. 23-2260) is the most likely venue where any formal resolution terms would be reflected.
Novartis v Mylan — key questions answered
Novartis asserted US11058667B2, a formulation patent covering ENTRESTO® (sacubitril/valsartan) tablets in three dose strengths: 24 mg/26 mg, 49 mg/51 mg, and 97 mg/103 mg. The application number on record is US15/572399.
The public record does not specify the precise reason for dismissal. The parties entered a 75-day joint stay stipulation in January 2024, citing ongoing proceedings in West Virginia and at the Federal Circuit. The case closed February 27, 2024 — before the stay’s April 8, 2024 expiry — suggesting the parties likely reached a resolution, though specific terms are not disclosed in the Delaware docket.
The basis of termination recorded is ‘Case Dismissed,’ but the public docket does not specify whether dismissal was with or without prejudice. Practitioners should review the full termination order to confirm the operative prejudice status and what rights Novartis retains to refile in Delaware.
Concurrent with the Delaware case, Novartis was pursuing Mylan in the U.S. District Court for the Northern District of West Virginia (No. 1:19-cv-201-TSK) and in a consolidated Federal Circuit appeal (No. 23-2260, consolidated with Lead Appeal No. 23-2218). These parallel proceedings were explicitly referenced in the January 2024 stay stipulation.
Novartis was represented by McCarter & English LLP, with attorneys including Daniel M. Silver, Nicholas N. Kallas, and Christopher E. Loh among others. Mylan was represented by Potter, Anderson & Corroon LLP, with David Ellis Moore, Robert L. Florence, and Tasneem A. Dharamsi on the record.
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