Patent 9,517,226 Scope and Claims: NEP inhibitor pro-drug LCZ696 for HFpEF left atrial remodeling and atrial fibrillation delay (US 9,517,226)
US 9,517,226 claims a specific therapeutic method using a named NEP inhibitor pro-drug (the molecule that corresponds to LCZ696/“sacubitril-valsartan” pro-drug component) and/or its parent NEP inhibitor, targeted to heart failure with preserved ejection fraction (HF-PEF) with left atrial enlargement and/or remodeling, measured by left atrial volume (and related indices/dimensions). The claim set is method-of-treatment focused, with dependent claims carving out atrial fibrillation (AF) treatment or prevention, NT-proBNP reduction and sustained NT-proBNP lowering, NYHA stabilization/delayed worsening, and combination with valsartan in a 1:1 molar ratio, plus dosing and LCZ696 salt/polymorph details.
What is US Patent 9,517,226 protecting and what is the core claim concept?
Core protection: A method for treating or delaying progression of HF-PEF characterized by left atrial enlargement/remodeling, where success is characterized by reducing left atrial volume, LAVI, and/or left atrial dimension, via administration of a NEP inhibitor pro-drug (or its corresponding NEP inhibitor) to a patient.
Independent claim role: Claim 1 is the anchor. It defines:
- Therapeutic agent identity (named NEP inhibitor pro-drug and/or its NEP inhibitor)
- Patient disease framing (HF-PEF, with atrial enlargement and/or remodeling)
- Outcome measure (left atrial volume and/or LAVI and/or left atrial dimension reduction)
This is a clinical endpoint constrained method claim, not a composition claim.
Adjacent claim boundaries created by Claim 1
Claim 1 is limited in three ways that matter for infringement analysis:
- Indication boundary: HF-PEF (not HFrEF, not generic “heart failure”).
- Anatomy/remodeling boundary: atrial enlargement/remodeling with measurable left atrial metrics.
- Drug identity boundary: administration of the specified NEP inhibitor pro-drug or NEP inhibitor (or salts).
How broad are the claims in US 9,517,226 in terms of drug identity and “pro-drug vs inhibitor”?
Claim 1 drug scope
Claim 1 covers two alternative active species:
- The NEP inhibitor pro-drug: the specific named chemical entity (pro-drug form)
- The NEP inhibitor: the corresponding NEP inhibitor compound (non-pro-drug form)
Practical implication for scope:
- Methods using either the pro-drug or the parent NEP inhibitor fall within claim 1 if other elements match (HF-PEF plus atrial remodeling endpoint).
- Methods using different NEP inhibitors not structurally identical to the named compounds are not captured by the literal wording.
Claim 9 tightens drug identity by specifying the delivered LCZ696 form
Claim 9 narrows claim 1/7/8 by specifying the pro-drug delivered by administration of LCZ696 as a specific chemical description:
trisodium[3-((1S,3R)-1-biphenyl-4-ylmethyl-3-ethoxycarbonyl-1-butylcarbamoyl) propionate-(S)-3′-methyl-2′-(pentanoyl{2″-(tetrazol-5-ylate)biphenyl-4′-ylmethyl}amino)butyrate]hemipentahydrate.
This is not generic “sacubitril” or “sacubitril-containing therapy.” It is a particular LCZ696 salt/hydrate/species description. So:
- Claim 9 is an explicit narrowing of the LCZ696 embodiment.
- A competitor using a different salt form, hydrate, or pro-drug presentation could evade claim 9 while still potentially meeting claim 1 (depending on whether claim 9’s dependent chain is required and whether the exact salt is part of the asserted claim).
What outcomes define infringement: left atrial volume, LAVI, and left atrial dimension?
Claim 1 infringement is conditioned on the treatment/delay of progression being characterized by:
- Reduction of left atrial volume
- Left atrial volume index (LAVI)
- Left atrial dimension
How this constrains claim scope
- The claim text uses “characterized by the reduction,” which ties the method to clinical effect/measurement. In enforcement, that usually means evidentiary reliance on trial endpoints, imaging protocols, and statistical outcome measures.
- A therapy that otherwise treats HF-PEF but does not target or does not produce the claimed left atrial metric reductions could be outside the claim depending on how “characterized by” is construed in litigation.
Independent claim design is “imaging/physiology endpoint” centric
Unlike method claims that stop at “administration of X,” this claim requires that the treatment or delay is characterized by specific left atrial remodeling endpoints. That makes the claim more difficult to prove through purely prescribing/labeling evidence; the accused regimen’s effect on LA volume metrics becomes central.
What does Claim 2 cover: atrial fibrillation treatment vs delaying new onset?
Claim 2 depends on claim 1 and covers:
- Treatment of atrial fibrillation, or
- Delaying the time until new onset of atrial fibrillation.
This adds an AF-related temporal/control dimension. Importantly:
- It does not require prior AF history (that is separately handled in claim 3).
- It aligns with HF-PEF left atrial remodeling as a driver for AF onset; the claim is still tethered to claim 1’s HF-PEF and LA remodeling endpoint structure.
What does Claim 3 add: patients with no history of atrial fibrillation?
Claim 3 depends on claim 1 and limits to:
- Patients with no history of atrial fibrillation.
This is a prophylaxis/baseline-history narrowing. For infringement scenarios:
- A regimen tested or prescribed to HF-PEF patients without prior AF would fit the history limitation.
- A regimen restricted to patients with established AF would not necessarily meet claim 3.
How do Claims 4 and 5 cover NT-proBNP as an effectiveness marker?
Claim 4: reducing plasma NT-proBNP
Claim 4 depends on claim 1 and limits to reducing:
Claim 5: sustained reduction in NT-proBNP concentration
Claim 5 depends on claim 1 and further specifies:
- The administration leads to a sustained reduction in plasma NT-proBNP.
Scope impact
These claims add biochemical endpoints layered on top of HF-PEF plus LA remodeling. In practice:
- A product could potentially affect NT-proBNP without producing the claimed LA volume metric reduction; then claim 4/5 would likely still fail unless the claim 1 LA endpoint is met.
- If the clinical program measures both NT-proBNP and LA remodeling, they increase the chance that multiple dependent claims are met simultaneously.
What does Claim 6 protect: NYHA class improvement/stabilization/delayed worsening?
Claim 6 depends on claim 1 and requires:
- Improvement, stabilization, or delayed worsening in NYHA classification in patients with heart failure.
This is a functional clinical status endpoint. It creates a path for infringement proof in outcomes trials that use NYHA endpoints, even if imaging or NT-proBNP data are contested (though claim 1’s LA endpoint still applies to any asserted dependent claim).
What does Claim 7 cover: combination with valsartan and how strong is the co-administration limitation?
Claim 7 depends on claim 1 and narrows to methods where:
- The NEP inhibitor pro-drug or NEP inhibitor is administered together, concomitantly, or sequentially with:
- valsartan or pharmaceutically acceptable salt.
Scope nuance: “together, concomitantly or sequentially”
This language is broad in real-world dosing timing:
- “Sequentially” can cover staggered dosing schedules, provided the method elements are satisfied.
- It reduces the design-around value of altering dosing time windows.
Litigable dependency structure
Because claim 7 is dependent, an accused regimen must also satisfy claim 1 (HF-PEF with LA remodeling endpoint via the specified NEP inhibitor) in addition to adding valsartan.
What does Claim 8 add: a 1:1 molar ratio valsartan to NEP inhibitor?
Claim 8 narrows claim 7 to:
- Administering the NEP inhibitor (or pro-drug) and valsartan in a 1:1 molar ratio.
This ratio element can be a critical infringement tripwire:
- If a competitor uses a different molar ratio formulation or different combination dosing that does not meet 1:1, claim 8 may not be met even if general concomitant valsartan use exists (claim 7 still might be at issue, depending on what’s asserted).
What does Claim 9 constrain: LCZ696 delivered as a specific trisodium hemipentahydrate species?
Claim 9 is a dependent narrowing specifying the LCZ696 species as:
- trisodium[...]hemipentahydrate with a very detailed chemical identity.
Scope effect
- Claim 9 ties the pro-drug embodiment to a specific salt/hydrate and chemical descriptor.
- In enforcement, this element is likely to be litigated on the accused product’s exact composition form (salt, hydrate, polymorph characteristics as relevant to the patent’s chemical description).
Design-around potential
- A developer switching to a different salt/hydrate/presentation for the same pro-drug active could seek to avoid claim 9 while still practicing the broader claim 1 approach, but only if they also remain within or outside the dependent-chain elements being asserted.
What does Claim 10 add: twice-daily dosing and specific dose levels?
Claim 10 depends on claim 9 and specifies:
- LCZ696 administered twice daily
- doses of 50 mg, 100 mg, 200 mg, or 400 mg
Infringement relevance
- If an accused label uses once daily, claim 10 is unlikely to be met.
- If an accused regimen uses dose strengths outside those listed, claim 10 likely fails.
- Still, claim 1 through 9 could remain potential targets if they do not depend on the specific dosing constraint being asserted.
How does this claim set map to modern HFpEF and AF clinical narratives?
While the patent text is outcome-measure based (LA volumes/dimensions, NT-proBNP, NYHA), the dependent claims align with a therapeutic hypothesis:
- NEP inhibition (with valsartan in the combination embodiments) improves HFpEF physiology, reduces atrial remodeling, reduces AF burden or delays onset, and produces biomarker and clinical status improvements.
This alignment matters because it affects the evidentiary record needed to prove infringement:
- Trials or observational studies that include LA volume imaging metrics, LAVI/dimensions, NT-proBNP, and NYHA class provide the best infringement proof for multiple dependent claims at once.
Patent landscape: what other US patents usually surround this scope, and how do they compete?
No landscape can be produced from the single input provided. US 9,517,226 scope and claims are given, but the patent landscape requires:
- the patent’s citation list,
- family members,
- assignees and prosecution history,
- related continuations/divisionals,
- and Orange Book and litigation linkages for the actual FDA-listed products.
Under the constraints, an accurate landscape cannot be generated without those data.
Claim strategy implications for licensing and litigation
1) What claim elements are hardest to prove
- The “characterized by” LA metric reductions (left atrial volume/LAVI/dimension) likely require imaging endpoint evidence.
- The specified drug identity and, in dependent form, the specific LCZ696 trisodium hemipentahydrate entity in claim 9 likely require product composition evidence.
2) What elements are easiest to document from product labeling and trial protocols
- Administration of a specific NEP inhibitor pro-drug (or parent inhibitor) and valsartan combination is often label-driven in HF programs.
- Twice daily dosing and allowed dose strengths can be mapped to the product’s approved dosing regimen.
3) What creates branching exposure scenarios
- If an accused therapy uses the same NEP inhibitor pro-drug but a different dosing schedule, it may still fall under claims 1–9 but avoid claim 10.
- If a competitor uses valsartan concomitantly but not at 1:1 molar ratio, it may avoid claim 8 while still implicating claim 7.
- If the therapy is not administered in the LCZ696 trisodium hemipentahydrate form, claim 9 may be avoidable while claim 7/8 remain potentially at issue depending on which dependent claim is asserted.
Timeline and expiration analysis: when does exclusivity end?
No exclusivity timeline can be computed from the claim text alone. A patent expiration analysis requires the patent’s filing date, priority date, any terminal disclaimers, PTA (patent term adjustment), and whether later patents in the family extend exclusivity. That data is not present.
Key Takeaways
- US 9,517,226 is a method-of-treatment patent anchored on HF-PEF patients with left atrial enlargement/remodeling, where therapeutic effect is characterized by reduced left atrial volume/LAVI/left atrial dimension.
- The claim set covers administration of a named NEP inhibitor pro-drug and/or its NEP inhibitor parent, with dependent claims branching into:
- AF treatment or delayed new-onset AF (claims 2–3),
- NT-proBNP reduction and sustained lowering (claims 4–5),
- NYHA improvement/stabilization/delayed worsening (claim 6),
- combination with valsartan and 1:1 molar ratio (claims 7–8),
- and a specific LCZ696 trisodium hemipentahydrate form and twice-daily dose strengths (claims 9–10).
- The most litigation-sensitive elements are the endpoint-based left atrial metric reduction and the composition and dosing specificity in dependent claims.
FAQs
1) Does US 9,517,226 cover heart failure with reduced ejection fraction (HFrEF)?
No. Claim 1 is limited to heart failure with preserved ejection fraction (HF-PEF).
2) If a therapy reduces NT-proBNP but does not reduce LAVI/left atrial volume, does it avoid infringement?
It does not necessarily avoid infringement, but the dependent NT-proBNP claims sit on top of claim 1, which requires LA metric reduction “characterized” by the treatment.
3) Can “sequential” valsartan co-administration satisfy claim 7?
Yes. Claim 7 explicitly includes administration “together, concomitantly or sequentially.”
4) Does claim 10 require twice-daily dosing and specific mg strengths?
Yes. Claim 10 is limited to twice daily dosing at 50/100/200/400 mg.
5) Is the LCZ696 form in claim 9 optional?
For claim 9 specifically, it is not optional. Claim 9 requires delivery of LCZ696 as the specified trisodium hemipentahydrate species.
References
- US Patent 9,517,226 (claims provided in prompt).
