Novartis v. Torrent Pharma: Federal Circuit Splits Decision on Entresto Patents
Novartis Pharmaceuticals brought this ANDA-driven infringement action to protect Entresto® (sacubitril/valsartan) — its blockbuster heart failure therapy — against ten generic challengers including Torrent, Hetero, MSN, Alembic, and Biocon. The Federal Circuit issued a mixed ruling after 529 days, affirming some patent claims and reversing others across two asserted patents.
Federal Circuit delivers split verdict on Novartis Entresto ANDA patents
Novartis Pharmaceuticals Corporation filed Case No. 23-2218 at the Court of Appeals for the Federal Circuit on July 31, 2023, appealing a lower-court ruling in its infringement action against ten generic pharmaceutical defendants seeking approval to market generic versions of Entresto® (sacubitril/valsartan) in 24/26 mg, 49/51 mg, and 97/103 mg tablet strengths. The two patents at issue — US8101659B2 and US8796331B2 — cover the sacubitril/valsartan combination that forms the active basis of Entresto, a first-in-class angiotensin receptor-neprilysin inhibitor (ARNi) approved for heart failure with reduced ejection fraction.
The Federal Circuit closed the case on January 10, 2025 with an order affirmed in part and reversed in part, with the basis of termination recorded as ‘Appeal Granted In Part.’ This mixed disposition means the court found reversible error in at least one aspect of the district court’s analysis while sustaining other portions. Neither Novartis nor the generic challengers achieved a clean sweep: some patent protections survive intact, while others were invalidated or found non-infringed, depending on which claims and which defendants were addressed by the reversed portion.
A 529-day pendency at the Federal Circuit is consistent with complex, multi-defendant pharmaceutical ANDA appeals involving claim construction and obviousness arguments. The split nature of the ruling is commercially significant: Novartis retains enforceability on affirmed claims, but the reversal creates a pathway for at least some generic entrants. The public record does not specify which claims or which defendants were affected by the reversal versus the affirmance, leaving the precise downstream market implications subject to further proceedings or agreed orders at the district court level.
Filing to Appeal Granted In Part in 529 days
529-day appeal — above the Federal Circuit median for ANDA pharmaceutical cases
Federal Circuit affirms in part, reverses in part: what the split ruling means
What ‘Affirmed in Part, Reversed in Part’ means at the Federal Circuit
A split Federal Circuit disposition means the appellate panel found no reversible error on certain issues (affirmed) but identified legal or factual error requiring correction on others (reversed). The lower court’s findings on affirmed issues stand with full preclusive effect. On reversed issues, the court’s error may relate to claim construction, obviousness analysis, or the scope of infringement — and those aspects are resolved in favor of the appellant on the reversed grounds.
Mixed appellate outcomeNovartis retains protection on affirmed claims — partial win
The affirmance preserves Novartis’s patent rights on those claims and defendants covered by the affirmed portion, maintaining Entresto’s exclusivity shield against those generic filers. However, the reversal weakens the overall enforcement position: Novartis cannot assert the reversed claims or findings against the relevant defendants, potentially accelerating generic entry by some — but not all — challengers in this consolidated action.
Partial patent survivalGeneric defendants gain a partial pathway to market — reversal opens door
The reversal component is a meaningful win for at least a subset of the ten generic defendants — Torrent, Hetero, MSN, Alembic, and/or Biocon entities. Where the Federal Circuit reversed, those challengers may now pursue FDA approval without facing injunctive bar from the reversed claims. However, the affirmed portion maintains legal obstacles for other defendants or other dosage-strength claims, meaning generic launch timelines will likely diverge across the defendant group.
Selective generic clearanceEntresto market exclusivity is fractured — generic pressure increases
Entresto® generated multi-billion-dollar annual revenues for Novartis. A split Federal Circuit ruling is a commercially adverse signal: it suggests the patent fortress is not impenetrable and raises the bar for continued enforcement. Competitors and investors should monitor whether the reversed portion triggers 180-day first-filer exclusivity for any ANDA applicant, and whether Novartis seeks en banc rehearing or certiorari to restore full protection on the reversed claims.
Partial genericisation riskFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | Novartis Pharmaceuticals Corporation | Company | Pharmaceutical innovator — holder of US8101659B2 and US8796331B2 covering Entresto®Search in Eureka ↗ |
| Defendant | TORRENT PHARMA INC. | Company | Generic pharma ANDA filers: Torrent, Hetero, MSN, Alembic, and Biocon entities seeking Entresto® market entrySearch in Eureka ↗ |
| Co-Defendant | Hetero USA, Inc. | Company | Search in Eureka ↗ |
| Co-Defendant | Alembic Pharmaceuticals Limited | Individual | Search in Eureka ↗ |
| Co-Defendant | Hetero Labs Limited | Individual | Search in Eureka ↗ |
| Co-Defendant | Hetero Labs Limited | Individual | Search in Eureka ↗ |
| Co-Defendant | Alembic Pharmaceuticals, Inc. | Company | Search in Eureka ↗ |
| Co-Defendant | MSN Pharmaceuticals, Inc. | Company | Search in Eureka ↗ |
| Co-Defendant | MSN Laboratories Private, Ltd. | Company | Search in Eureka ↗ |
| Co-Defendant | Torrent Pharmaceuticals, Ltd. | Company | Search in Eureka ↗ |
| Co-Defendant | Biocon, Ltd. | Company | Search in Eureka ↗ |
| Co-Defendant | MSN Life Sciences Private, Ltd. | Company | Search in Eureka ↗ |
| Plaintiff counsel | Christina A. L. Schwarz | Attorney | Counsel for Novartis Pharmaceuticals CorporationSearch in Eureka ↗ |
| Plaintiff counsel | Deanne Maynard | Attorney | Counsel for Novartis Pharmaceuticals CorporationSearch in Eureka ↗ |
| Plaintiff counsel | Nicholas Nick Kallas | Attorney | Counsel for Novartis Pharmaceuticals CorporationSearch in Eureka ↗ |
| Plaintiff counsel | Seth W. Lloyd | Attorney | Counsel for Novartis Pharmaceuticals CorporationSearch in Eureka ↗ |
| Plaintiff law firm | Morrison & Foerster LLP | Law Firm | Representing Novartis Pharmaceuticals CorporationSearch in Eureka ↗ |
| Plaintiff law firm | Venable LLP | Law Firm | Representing Novartis Pharmaceuticals CorporationSearch in Eureka ↗ |
| Defendant counsel | Neal C. Belgam. | Attorney | Counsel for TORRENT PHARMA INC.Search in Eureka ↗ |
| Defendant law firm | Smith, Katzenstein, & Jenkins, LLP | Law Firm | Representing TORRENT PHARMA INC.Search in Eureka ↗ |
| Presiding judge | Judge N/A | Judge | Court of Appeals for the Federal CircuitSearch in Eureka ↗ |
Official order — verbatim text
The order ‘AFFIRMED IN PART, REVERSED IN PART’ reflects a nuanced Federal Circuit review applying de novo scrutiny to legal questions such as claim construction and a clear-error standard to factual findings. The split disposition confirms the panel found merit in some — but not all — of the challengers’ appellate arguments. Because the public record does not detail which specific claims or defendants fall on each side of the line, the precise scope of remaining exclusivity requires careful reading of the full opinion, particularly any claim-by-claim or defendant-by-defendant breakdown in the majority’s analysis.
US8101659B2 & US8796331B2 — sacubitril/valsartan ARNi combination therapy
US8101659B2 (application US12/147570) and US8796331B2 (application US13/687659) are the two Novartis patents asserted in this action, covering the sacubitril/valsartan active pharmaceutical combination that underlies Entresto® — the first approved angiotensin receptor-neprilysin inhibitor (ARNi). The patents protect the compound and/or composition aspects of the supramolecular complex formed between sacubitril (a neprilysin inhibitor prodrug) and valsartan (an ARB), a structurally distinct entity from either component used alone. The filing timeline of the two applications suggests layered protection across the molecule and its formulated forms.
Entresto® achieved blockbuster status on the strength of the PARADIGM-HF trial, demonstrating mortality benefit in heart failure with reduced ejection fraction. The two patents therefore protect one of the most commercially significant cardiovascular drug franchises of the past decade. Generic challengers across the ANDA landscape — including major Indian generics houses such as Torrent, Hetero, MSN, Alembic, and Biocon — mounted coordinated Paragraph IV challenges, signalling broad industry confidence that the patents were potentially vulnerable. The Federal Circuit’s partial reversal validates that assessment and reshapes the competitive landscape for the post-exclusivity Entresto market.
Should your team run an FTO against US8101659B2 and US8796331B2?
Any pharmaceutical company, formulator, or API supplier working in the ARNi class — or developing heart failure therapies involving neprilysin inhibition combined with renin-angiotensin system blockade — should conduct a thorough freedom-to-operate analysis against both Novartis patents. The partial reversal means that claim-level mapping is essential: not all claims are equally enforceable, and the affirmed claims retain full legal weight against potential generic or 505(b)(2) applicants not party to this litigation.
PatSnap Eureka’s FTO Search Agent can map your compound or formulation against the claim trees of US8101659B2 and US8796331B2, flag prosecution history estoppel from both file wrappers, and surface relevant prior art cited in the Federal Circuit’s reversal analysis. For pipeline teams evaluating ARNi assets or sacubitril analogue programmes, Eureka’s landscape analysis also identifies white-space claims and potential design-around opportunities validated by the appellate record.
Run a freedom-to-operate analysis on US8101659B2 to assess your product’s exposure
Run FTO in Eureka →Similar Federal Circuit ANDA patent appeals in cardiovascular pharma
Explore comparable Federal Circuit ANDA infringement appeals involving heart failure and cardiovascular drug patents, including ARNi and ARB combination therapy cases.
What this split ruling signals for pharmaceutical ANDA patent strategy
A partial Federal Circuit reversal on a blockbuster ANDA portfolio is a rare and commercially consequential event — with lessons for both innovators and challengers.
Multi-patent ANDA portfolios reduce — but do not eliminate — reversal exposure
Novartis’s two-patent strategy meant a single reversal did not eliminate all protection. Innovators filing ANDA suits should build layered claim portfolios across multiple patents with different priority dates and independent claim scopes to ensure that a partial appellate loss does not create a complete clearance for generic filers.
Ten-defendant consolidation amplifies the stakes of any single appellate ruling
Consolidating ten ANDA defendants into one appeal creates efficiency but concentrates risk. A reversal affecting even one claim in a consolidated proceeding can benefit multiple generic filers simultaneously, accelerating market entry across the group. Innovators should assess whether defendant-specific bifurcation offers better downside protection for high-value assets.
Novartis v TORRENT — key questions answered
The Federal Circuit issued an order affirmed in part and reversed in part on January 10, 2025, in Case No. 23-2218. The court upheld portions of the lower-court ruling protecting Novartis’s Entresto (sacubitril/valsartan) patents while reversing other portions, granting the appeal in part. The specific claims and defendants affected by each portion require review of the full opinion.
Novartis asserted two patents: US8101659B2 (application US12/147570) and US8796331B2 (application US13/687659). Both cover aspects of the sacubitril/valsartan combination compound and/or compositions that form the active basis of Entresto®, the ARNi heart failure therapy approved in 24/26 mg, 49/51 mg, and 97/103 mg tablet strengths.
Ten generic pharmaceutical entities were defendants: Torrent Pharma Inc., Torrent Pharmaceuticals Ltd., Hetero USA Inc., Hetero Labs Limited (two entries), MSN Pharmaceuticals Inc., MSN Laboratories Private Ltd., MSN Life Sciences Private Ltd., Alembic Pharmaceuticals Limited, Alembic Pharmaceuticals Inc., and Biocon Ltd. All had filed ANDAs with Paragraph IV certifications seeking to market generic sacubitril/valsartan.
A split Federal Circuit disposition means Novartis retains enforceable patent rights on affirmed claims, blocking some or all generic filers on those grounds. On reversed issues, the legal bar to generic entry is removed, potentially allowing affected ANDA holders to seek final FDA approval. The precise generic launch timeline depends on which defendants and claims fall on each side and whether FDA Orange Book first-filer exclusivity periods apply.
The appeal ran for 529 days, from filing on July 31, 2023 to the decision on January 10, 2025. This duration is consistent with complex multi-defendant pharmaceutical ANDA appeals at the Federal Circuit, which typically involve extensive briefing on claim construction, obviousness, and fact-intensive infringement analyses across multiple patents and dosage forms.
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