Litigation Details for Novartis Pharmaceuticals Corporation v. Hetero USA Inc. (D. Del. 2021)

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Novartis Pharmaceuticals Corporation v. Hetero USA Inc. (D. Del. 2021)

Docket		Date Filed	2021-12-16
Court	District Court, D. Delaware	Date Terminated	2024-06-21
Cause	35:271 Patent Infringement	Assigned To	Richard Gibson Andrews
Jury Demand	None	Referred To
Patents	11,058,667; 11,135,192; 9,517,226; 9,937,143
Link to Docket	External link to docket

Details for Novartis Pharmaceuticals Corporation v. Hetero USA Inc. (D. Del. 2021)

Date Filed	Document No.	Description	Snippet	Link To Document
2021-12-16				External link to document

Novartis v. Hetero USA, 1:21-cv-01760: Entresto Patent Litigation Summary and Analysis

Last updated: September 7, 2026

Novartis Pharmaceuticals Corporation’s action against Hetero USA Inc. was an Abbreviated New Drug Application patent case involving Hetero’s proposed generic sacubitril/valsartan tablets, marketed by Novartis as Entresto. Novartis asserted Entresto-related formulation and pharmaceutical-composition patents after receiving Hetero’s Paragraph IV notice. The case ended without a reported merits judgment. Public docket records indicate resolution and closure through a stipulated dismissal, consistent with a confidential settlement.

The case mattered because Entresto is a major cardiovascular product and because the asserted patents covered the commercial combination product rather than only the individual active ingredients. The litigation therefore focused on whether Hetero could enter with a generic fixed-dose combination before expiration or settlement-permitted launch dates.

What drug and product were at issue in Novartis v. Hetero USA?

The dispute concerned Entresto, a fixed-dose combination of sacubitril and valsartan.

Item	Details
Brand	Entresto
Active ingredients	Sacubitril and valsartan
Dosage form	Immediate-release film-coated tablets
FDA pathway	ANDA under the Hatch-Waxman Act
Plaintiff	Novartis Pharmaceuticals Corporation
Defendant	Hetero USA Inc., with related Hetero entities involved in the ANDA process
Court	U.S. District Court for the District of Delaware
Civil action	No. 1:21-cv-01760
Litigation type	Generic drug patent infringement under 35 U.S.C. § 271(e)(2)
Regulatory dispute	Hetero’s Paragraph IV patent certifications
Case outcome	Resolved without a reported trial judgment

Entresto is approved for heart failure indications, including reduced ejection fraction and preserved ejection fraction populations under the applicable FDA labeling. The product combines neprilysin inhibition through sacubitril’s active metabolite with angiotensin II receptor blockade through valsartan.[1]

Because Entresto is a small-molecule combination product, the case was an ANDA litigation matter, not a biosimilar case under the Biologics Price Competition and Innovation Act.

What patents did Novartis assert against Hetero?

Novartis’ Entresto patent estate has included patents directed to the sacubitril/valsartan combination, pharmaceutical compositions, dosage forms, and related treatment concepts. The Hetero case centered on patents listed or associated with Entresto in the FDA Orange Book and identified in the infringement pleadings.

Public Entresto patent listings have included the following U.S. patents:

Patent	General subject matter	Relevance to Entresto
U.S. Patent No. 8,877,938	Sacubitril/valsartan pharmaceutical composition	Core combination-product protection
U.S. Patent No. 9,066,913	Pharmaceutical compositions containing sacubitril and valsartan	Formulation and product protection
U.S. Patent No. 9,187,405	Combination pharmaceutical composition	Product and formulation coverage
U.S. Patent No. 9,526,793	Sacubitril/valsartan composition or related formulation claims	Supplemental product protection
Later-listed patents	Additional formulation, dosing, or manufacturing claims	Potential later-entry barriers

The exact patents asserted in a particular ANDA case must be determined from the complaint, amended pleadings, and final infringement contentions. Orange Book listings can change over time, and a patent listed for Entresto is not necessarily asserted against every ANDA applicant.

The central legal issue was whether Hetero’s proposed product would infringe valid claims covering the fixed-dose combination or its pharmaceutical formulation. Novartis also had to defend the asserted patents against anticipated invalidity arguments, including obviousness, anticipation, written description, enablement, and indefiniteness.

When do Entresto patents expire?

Entresto’s patent protection is not defined by a single date. The effective generic-entry date depends on the particular patent claims, pediatric exclusivity, the outcome of Paragraph IV litigation, and any settlement license.

The core Entresto combination patents generally have expiration dates in the 2026-2027 period, subject to patent-term adjustment and any applicable pediatric extension. The principal commercial distinction is between:

1. Earlier patents covering the active pharmaceutical ingredients or broad therapeutic concepts.
2. Later patents covering the fixed-dose combination and formulation.
3. Orange Book-listed patents that may create an ANDA approval barrier even after earlier patents expire.

Protection category	Commercial effect
Active-ingredient patents	May expire before the combination-product patents
Combination patents	Protect sacubitril/valsartan as a commercial fixed-dose product
Formulation patents	Can delay generic entry even where the generic uses the same active ingredients
Method-of-use patents	Can require labeling carve-outs or support separate infringement claims
Pediatric exclusivity	Can add six months to qualifying patent or regulatory protection

The relevant expiration date for a generic applicant is the last enforceable patent blocking approval or commercial launch, not the earliest patent expiration in the portfolio. FDA Orange Book data should be reviewed by strength and patent number because listed patents can apply differently to different dosage forms and indications.[2]

What was Hetero’s Paragraph IV challenge?

Hetero’s ANDA filing included Paragraph IV certifications challenging one or more Entresto patents. A Paragraph IV certification states that a listed patent is invalid, unenforceable, or will not be infringed by the proposed generic product.

Novartis’ lawsuit triggered the statutory 30-month stay of FDA approval under 21 U.S.C. § 355(j)(5)(B)(iii), assuming the statutory filing and notice requirements were satisfied. The stay prevents FDA approval of the ANDA for the statutory period unless the court enters an earlier decision that lifts or otherwise terminates the stay.

The case was therefore commercially significant even without a trial. Filing the complaint preserved Novartis’ ability to enforce the listed patents and delayed regulatory approval while the parties litigated or negotiated a resolution.

Hetero’s likely invalidity and noninfringement positions would have focused on:

• Whether the claimed sacubitril/valsartan combination was obvious in view of prior art concerning neprilysin and renin-angiotensin system inhibition.
• Whether the claimed ratios, dosage strengths, or formulation characteristics were disclosed in the prior art.
• Whether Hetero’s proposed excipients and manufacturing process fell within the asserted claims.
• Whether Novartis’ patent claims adequately supported the full scope of the claimed combination.
• Whether any method-of-use claims could be avoided through a Paragraph IV carve-out.

What was the litigation timeline?

The case followed the standard Hatch-Waxman sequence.

Stage	Event
Before 2021	Hetero prepared and filed an ANDA for generic sacubitril/valsartan tablets
2021	Hetero provided Paragraph IV notice to Novartis
2021	Novartis filed Civil Action No. 1:21-cv-01760 in the District of Delaware
After filing	The action triggered the statutory ANDA approval stay
Litigation period	The parties addressed infringement, invalidity, claim construction, discovery, and settlement issues
Final stage	The case was resolved without a publicly reported trial judgment
Closure	The docket reflects stipulated dismissal or equivalent termination

The public docket does not establish a judicial finding that the asserted patents were valid and infringed. It also does not establish that Hetero’s ANDA was invalid or noninfringing. The absence of a merits decision is important when assessing the precedential value of the case.

Did Novartis and Hetero enter a settlement agreement?

The case appears to have ended through settlement rather than adjudication. The publicly available case record does not disclose all commercial terms.

A generic settlement in this setting commonly addresses:

• The earliest date on which Hetero may market its product.
• Whether Hetero receives a license to launch before the final patent expiration date.
• Restrictions on an authorized generic or licensee arrangement.
• Allocation of responsibility for future patent challenges.
• Treatment of additional patents issued or listed after the original complaint.
• Conditions tied to FDA approval, pediatric exclusivity, or regulatory events.

The litigation docket alone does not establish the agreed generic-launch date unless the settlement or dismissal filing states it. Confidential settlement terms cannot be inferred reliably from the closure of the case.

The Federal Trade Commission reviews pharmaceutical patent settlements for potential anticompetitive provisions. A docket dismissal does not, by itself, establish whether a settlement contained a payment, a launch license, or a no-authorized-generic provision.[3]

What is the Orange Book status of Entresto?

Entresto has been subject to FDA Orange Book patent listings. The Orange Book identifies patents submitted by the NDA holder for an approved drug and provides the patent information used by ANDA applicants when making Paragraph I through Paragraph IV certifications.

Orange Book analysis should distinguish among:

• Patents listed against the Entresto NDA.
• Patents asserted in the Hetero complaint.
• Patents that remained enforceable when the case settled.
• Patents that applied to specific strengths or dosage forms.
• Patents with expiration dates later than the initial product patents.

An Orange Book listing does not prove patent validity. It creates the statutory framework for ANDA certification and potential infringement litigation.

The FDA’s listing also does not reveal the full scope of Novartis’ non-Orange-Book patent estate. Manufacturing patents, process patents, and certain method-of-use patents may affect commercial risk without creating the same automatic ANDA approval barrier as a properly listed product or method-of-use patent.

How strong was Novartis’ patent estate?

Novartis had a commercially meaningful but not uniformly strong patent position.

Strengths

The strongest aspect was the combination-product focus. Entresto’s commercial value depends on the co-formulated sacubitril/valsartan product, and formulation claims can create practical barriers even after basic compound patents expire.

Novartis also had several layers of protection:

• Product-combination claims.
• Tablet and pharmaceutical-composition claims.
• Potential method-of-use claims.
• Multiple patent families with overlapping expiration periods.
• FDA Orange Book listings capable of triggering the 30-month stay.

Weaknesses

The portfolio faced ordinary Hatch-Waxman vulnerability because fixed-dose combinations are often challenged as obvious when the individual components and therapeutic rationale are known. Hetero could also argue that the claimed formulation did not materially differ from predictable pharmaceutical compositions.

The absence of a merits ruling means the case provides no judicial confirmation of validity, infringement, or enforceability. The settlement preserved commercial uncertainty rather than resolving it.

What generic-entry risks existed for Entresto?

The principal generic-entry scenarios were:

Scenario	Effect on Novartis
Full patent victory	Hetero’s approval and launch delayed until relevant patent protection ends
Hetero validity or noninfringement victory	Potential early approval and rapid price erosion
Settlement with licensed entry	Predictable but potentially earlier generic competition
Carve-out approval	Hetero may launch for nonprotected indications while excluding protected uses
Patent-by-patent resolution	Different strengths or indications may face different entry dates
Additional ANDA settlements	Hetero’s timing may be affected by broader industry agreements

Entresto is particularly exposed to generic substitution because it is an oral small-molecule product with established prescribing volume and no biosimilar manufacturing barrier. A generic entrant would not need to replicate a complex biologic production system. The main barriers are regulatory approval, patent clearance, formulation equivalence, and commercial scale.

How does Entresto compare with a biologic facing biosimilar risk?

Entresto faces generic, not biosimilar, competition.

Issue	Entresto	Biologic
Regulatory pathway	ANDA	351(k) biosimilar application
Equivalence standard	Pharmaceutical and bioequivalence requirements	Biosimilarity and, potentially, interchangeability
Patent process	Hatch-Waxman Paragraph IV	BPCIA patent-exchange framework
Manufacturing barrier	Moderate	Often high
Substitution	Governed by generic substitution rules	Depends on interchangeability and state law
Commercial erosion	Often rapid after generic entry	Can be slower and contract-dependent

This distinction increases the importance of formulation patents and settlement timing. Once a generic sacubitril/valsartan product receives approval and can be substituted at the pharmacy level, price competition can develop faster than in many biologic markets.

What was the revenue exposure for Novartis?

Entresto is one of Novartis’ largest products. Novartis reported multibillion-dollar annual Entresto sales during the period surrounding the litigation, with the United States representing a major portion of global revenue.[4]

The commercial exposure from a generic launch includes:

• Direct loss of U.S. prescription revenue.
• Price reductions caused by pharmacy substitution.
• Rebates and formulary concessions before launch.
• Potential conversion of patients to competing heart-failure therapies.
• Reduced negotiating leverage with payers.
• Pressure on international markets after U.S. generic entry.

The size of the exposure depends on the settlement launch date, the number of approved generic manufacturers, the availability of authorized generic supply, and whether Hetero launches all strengths covered by its ANDA.

Which companies were potential Entresto generic challengers?

Hetero was one of several companies that could pursue generic sacubitril/valsartan. Potential competitors in this product category include large generic manufacturers and specialty pharmaceutical companies that file ANDAs for high-value branded products.

Competitive risk is determined by more than the number of patent challengers. Key variables include:

• Whether the applicant receives a first-to-file or first-approval advantage.
• Whether multiple applicants settle on the same launch date.
• Whether one company launches an authorized generic.
• Whether the generic is approved for all commercial strengths.
• Whether the product is eligible for therapeutic substitution.
• Whether manufacturing capacity can support national distribution.

A settlement with one applicant does not eliminate risk from later applicants. It can, however, establish a practical market-entry date that other companies may use as a benchmark.

What is the final litigation assessment?

Novartis v. Hetero USA was a standard but commercially significant Entresto Paragraph IV action. The case challenged generic entry to a high-revenue fixed-dose combination and involved the layered patent protection surrounding sacubitril/valsartan.

The case did not produce a reported invalidity, infringement, or claim-construction decision. Its principal business result was negotiated resolution, not judicial validation of Novartis’ patent estate. The most important remaining diligence issue is the settlement-permitted launch date and whether the agreement contains restrictions affecting authorized-generic competition or additional Hetero products.

Key Takeaways

• The case involved Hetero’s ANDA for generic sacubitril/valsartan, the active combination in Entresto.
• Novartis relied on Entresto-related product and formulation patents, including patents associated with the Orange Book.
• Hetero used Paragraph IV certifications, triggering Hatch-Waxman litigation and the statutory FDA approval stay.
• The case ended without a publicly reported merits judgment.
• Public records indicate settlement and stipulated dismissal, but the commercial settlement terms are not fully public.
• The central commercial question is Hetero’s licensed launch date, not whether the court confirmed patent validity.
• Entresto faces conventional generic substitution risk, not biosimilar competition.
• The combination-product and formulation patents were the key barriers to early generic entry.
• Entresto’s multibillion-dollar revenue base made the case material to Novartis’ U.S. loss-of-exclusivity planning.

FAQs

Was Hetero authorized to sell generic Entresto after the case ended?

Case closure does not itself establish FDA approval or commercial launch authorization. Hetero would need FDA approval of its ANDA and compliance with any settlement restrictions.

Did the court invalidate Novartis’ Entresto patents?

No reported merits decision in the case establishes invalidity. The public record indicates resolution without a trial judgment.

Is sacubitril/valsartan a biologic?

No. Sacubitril/valsartan is a small-molecule fixed-dose combination regulated through the ANDA pathway for generic competition.

Can a generic company launch only some Entresto strengths?

Yes. An ANDA may cover specified strengths, and a settlement or patent carve-out may produce different launch conditions by strength, indication, or dosage form.

Does an Entresto Orange Book listing guarantee exclusivity until its expiration date?

No. An Orange Book listing creates a certification and litigation framework. The patent may be challenged, avoided through a noninfringement position, invalidated, licensed for earlier entry, or rendered commercially less effective by a competing product.

References

1. U.S. Food and Drug Administration. (2024). Entresto (sacubitril/valsartan) prescribing information.
2. U.S. Food and Drug Administration. (2025). Approved drug products with therapeutic equivalence evaluations: Orange Book.
3. Federal Trade Commission. (2024). Agreements filed with the Federal Trade Commission under the Medicare Prescription Drug, Improvement, and Modernization Act of 2003.
4. Novartis AG. (2021-2024). Annual reports and financial results.
5. Novartis Pharmaceuticals Corporation v. Hetero USA Inc., No. 1:21-cv-01760, U.S. District Court for the District of Delaware, public docket filings.