United States Patent 11,919,838: What the Claims Actually Cover and How the Landscape Likely Shapes Freedom to Operate
US 11,919,838 is framed as a method-of-use patent that uses a specific small-molecule scaffold (the “compound of the formula” with substituent variables R1 and R2, and bonds between “carbon 9 and carbon 11”) to activate the Keap1/Nrf2/ARE pathway and, separately, to reduce oxidative stress by the same mechanism class. The claims then broaden into systemic administration and dose ranges (0.1-1000 mg/kg) for in vivo use.
Because the claims you provided are limited to the method and substituent/bond/dosing parameters, the scope is driven by (i) what compounds fall inside the formula definition, (ii) whether “carbon 9-carbon 11” is required to be single vs double, and (iii) what qualifies as “contacting” (in vitro) vs “administered” (in vivo), with dose and route defining a practical boundary for infringement and design-around.
What is the claim structure and what is the legally operative scope?
The independent claims are claim 1 and claim 9, each anchored to a “method” and each tied to the same general compound formula.
Independent claim 1 (activation of Keap1/Nrf2/ARE)
Claim 1 recites:
- A method of activating the antioxidant/anti-inflammatory Keap1/Nrf2/ARE pathway in a cell.
- By contacting the cell with an effective amount of a compound of the formula, where:
- R1 and R2 are independently selected from a defined set of substituents:
- hydrogen, or
- alkyl (c ≤ 12), alkenyl (c ≤ 12), alkynyl (c ≤ 12)
- aryl (c ≤ 12), aralkyl (c ≤ 12)
- heteroaryl (c ≤ 12), heteroaralkyl (c ≤ 12)
- acyl (c ≤ 12)
- alkylsulphonyl, alkenylsulphonyl (c ≤ 12), alkynylsulphonyl (c ≤ 12)
- arylsulphonyl (c ≤ 12), aralkylsulphonyl (c ≤ 12)
- heteroarylsulphonyl (c ≤ 12), heteroaralkylsulphonyl (c ≤ 12)
- “a substituted version of any of these groups”
- plus pharmaceutically acceptable salts, tautomers, or optical isomers
- No explicit restriction is given in claim 1 on the bond between carbon 9 and carbon 11; that is added in dependent claims 2 and 3.
Dependent claims 2–3 (carbon 9-carbon 11 bond state)
- Claim 2: bond between carbon 9 and carbon 11 is a double bond
- Claim 3: bond between carbon 9 and carbon 11 is a single bond
These two claims materially impact claim interpretation if the formula allows either possibility. If the drawing/definition in the specification describes both, these dependents become explicit coverage hooks for each bond type.
Dependent claims 4–8 (in vivo systemic dosing and routes; dosage frequency)
Claim 4:
- Cell is in a subject
- Compound is administered to the subject systemically
Claim 5:
- Route options: intravenously, intra-arterially, intramuscularly, intraperitoneally, subcutaneously, or orally
Claim 6:
Claim 7–8:
- Dosing frequency: single dose per day (claim 7) or two or more doses per day (claim 8)
Dependent claims 5, 6, 7, 8 narrow, but do not eliminate broad infringing practice
Even though these are dependent, their presence signals the patent holder expects enforcement across typical systemic dosing paradigms and broad dose selection, rather than a narrow therapeutic window.
Independent claim 9 (reducing oxidative stress)
Claim 9 is parallel to claim 1, but replaces the functional target:
- Method of reducing oxidative stress in a cell
- Achieved by contacting with an effective amount of a compound of the same formula with the same R1/R2 definition and same allowance for salts, tautomers, optical isomers.
- Dependent claims 10–16 mirror claims 2–8:
- bond between carbon 9 and 11 as double (claim 10) or single (claim 11)
- systemic administration (claims 12–13)
- dose 0.1–1000 mg/kg (claim 14)
- dosing frequency single daily (claim 15) or two or more daily (claim 16)
Practical legal implication: two usage theories, same compound perimeter
Having both claims means an accused product does not only have to be positioned as an “activator of Keap1/Nrf2/ARE.” If the compound produces oxidative stress reduction in the asserted manner, the second claim theory can still be pursued.
What compounds are inside the formula perimeter, based on the text provided?
The scope is “formula-first.” The claim text you provided does not reproduce the full chemical structure, but it does constrain the allowable substituent space:
Substituent variable scope for R1 and R2
Each of R1 and R2 can independently be:
- H
- Hydrocarbon and unsaturated variants:
- alkyl, alkenyl, alkynyl with c ≤ 12
- Aromatic and heteroaromatic:
- aryl, aralkyl, heteroaryl, heteroaralkyl with c ≤ 12
- Carbonyl-containing:
- Sulphonyl-containing:
- alkylsulphonyl, alkenylsulphonyl(c ≤ 12), alkynylsulphonyl(c ≤ 12)
- arylsulphonyl(c ≤ 12), aralkylsulphonyl(c ≤ 12)
- heteroarylsulphonyl(c ≤ 12), heteroaralkylsulphonyl(c ≤ 12)
- “substituted versions” of any above
- Plus pharmaceutically acceptable salts, tautomers, optical isomers
Bond state scope
The patent makes separate dependent coverage for:
- double bond between carbon 9 and carbon 11, and
- single bond between carbon 9 and carbon 11
If the core scaffold supports both, these dependents give the holder two enforcement wedges.
The key inclusion/exclusion leverage point for design-around
A competitor likely has only three meaningful levers relative to these claims:
- Avoid the specific “compound of the formula” entirely (most reliable design-around).
- Stay within the same scaffold but alter substitution so that R1/R2 no longer fall within the allowed sets (less clear without the full structure).
- Operate outside the method conditions (e.g., avoid systemic administration, avoid the 0.1–1000 mg/kg dosing band, or avoid the “effective amount” profile that maps to infringement theory). Claim language still leaves room for the patent holder to argue “effective amount” covers a wide range.
Because the R1/R2 set is broad, and the dose band is wide, the “carve-outs” via dosing are narrow in practical terms unless a development program is intentionally outside the stated range or route.
How broad are the method steps and what does “systemic” plus route imply for FTO?
The method can be practiced:
- In vitro / ex vivo: “contacting the cell” (claims 1 and 9 are not restricted to administration).
- In vivo: dependent claims add “cell located in a subject” and “administered…systemically” (claims 4 and 12).
Route options (claims 5 and 13) cover essentially all mainstream systemic channels:
- IV, intra-arterial, IM, intraperitoneal, subcutaneous, oral
That route set reduces the ability to avoid infringement by selecting an alternate administration route.
Dose band is extremely permissive
Claim 6 and claim 14 state 0.1–1000 mg/kg.
This is a very wide numerical range for small-molecule systems. For FTO, it means that a product tested and marketed in typical preclinical and clinical dose regimes that fall anywhere inside that band will likely land within the claim’s dosage parameter, assuming “effective amount” is satisfied.
Dosing frequency dependence
Claims 7–8 and 15–16 add “single dose per day” or “two or more doses per day,” which are both common in practice. Together they cover most oral and parenteral schedules.
How should this patent be positioned inside a “Keap1/Nrf2/ARE activation” patent landscape?
Even without reproducing the full compound structure, this claim set indicates the holder’s strategy:
- Mechanism anchoring: Keap1/Nrf2/ARE activation (claim 1) and oxidative stress reduction (claim 9) are two functional gates.
- Compound formula breadth: R1 and R2 options are broad across small and medium-sized substituent groups, including sulphonyl functionality.
- Delivery realism: systemically administered, broad routes, wide dose range.
In landscape terms, this patent typically sits among other Nrf2-pathway patents in one of two ways:
- Compound-subclass patents: those that define chemical scaffolds and claim in vivo use by functional outcome (this patent does that).
- Method-of-treatment patents that claim use of Nrf2 activators for specific diseases (not shown in your claim excerpt).
If competing programs use a different scaffold or different mechanistic mode (e.g., direct Nrf2 activators vs Keap1 modulators), they may still face these claims if the final delivered molecule falls into the formula.
What are the likely claim construction pinch points that drive infringement risk?
1) “compound of the formula” defines the real boundary
The claims rely on a formula with R1/R2 variables and carbon 9-carbon 11 bond state. Without the structural depiction, the practical risk assessment becomes about whether competitor molecules can be shown not to satisfy the formula definition.
2) “effective amount” is not numerically defined
Aside from the dependent dose band (0.1–1000 mg/kg), the claim uses “effective amount” in claim 1 and claim 9. The dependent dose claims likely exist to pin down dosage practices, but the independent claims still have functional reach if an accused dosing regimen plausibly meets effectiveness.
3) “contacting the cell” covers broad experimental setups
In vitro assays used in screening or preclinical studies could be implicated if the accused compound activates Keap1/Nrf2/ARE in cells and uses the covered compound. That matters for research collaborations and for internal SAR studies when the goal is to show pathway activation.
What is the actionable “freedom-to-operate” posture implied by this claimset?
If a competitor’s candidate compound matches the formula perimeter
Then the patent’s method claims are likely directly relevant for:
- Indication strategies built around Keap1/Nrf2/ARE activation
- Oxidative stress reduction endpoints in cell-based models
- Systemic delivery plans using common routes
- Dosing regimens that sit between 0.1–1000 mg/kg
If a competitor avoids the formula perimeter
Then the patent is less likely to be a blocking issue because the claims appear to be limited to a “compound of the formula” rather than a functional genus like “any Nrf2 activator.”
If a competitor stays within the formula but tries to design around by use
Given the breadth of:
- route selection (claims 5 and 13),
- dose band (claims 6 and 14),
- dosing frequency (claims 7–8 and 15–16),
design-around through route and dosage is unlikely to be sufficient. A strategy would more likely depend on chemistry changes that remove literal or interpretive coverage, or on use outside the dependent limitations if the accused practice is constrained.
What does the claim set imply about enforceable scope breadth across commercialization?
The dependent claims collectively indicate the holder is targeting:
- Oral and parenteral commercial delivery (oral is explicitly listed)
- Standard clinical and translational dosing regimes in preclinical animal contexts (mg/kg band)
- Both single and split daily dosing schedules
So the likely enforcement posture is not limited to a narrow administration scenario.
Key Takeaways
- US 11,919,838 is a method-of-use patent for Keap1/Nrf2/ARE activation and oxidative stress reduction, tied to a specific chemical formula with broad R1/R2 substituent coverage and optional single vs double bond between carbon 9 and carbon 11 (claims 2–3 and 10–11).
- The in vivo dependent claims cover systemic administration via IV, intra-arterial, IM, intraperitoneal, subcutaneous, or oral (claims 4–5 and 12–13).
- The dosing parameter is extremely broad: 0.1–1000 mg/kg (claims 6 and 14) with common frequency options (once daily vs two or more daily) (claims 7–8 and 15–16).
- From an FTO perspective, the primary determinant is whether a candidate compound is within the “compound of the formula” boundary; avoidance via route or dosing alone is likely weak given the claim breadth.
FAQs
1) Does the patent require proof of Keap1/Nrf2/ARE activation to infringe claim 9?
No. Claim 9 is framed as reducing oxidative stress. Claim 1 explicitly targets Keap1/Nrf2/ARE activation. Having both gives the holder two functional infringement theories.
2) Is the method limited to a specific administration route?
No. Listed routes include IV, intra-arterial, IM, intraperitoneal, subcutaneous, and oral when practicing the dependent systemic claims.
3) Can a candidate avoid risk by dosing outside 0.1–1000 mg/kg?
The dependent claims require that dose range, but the independent claims still require an “effective amount.” A full risk elimination strategy would need to address both the compound formula and the functional “effective amount” requirement.
4) Does the patent cover both single and double bonds at carbon 9-carbon 11?
Yes. Dependent claims cover each bond state separately: claim 2 (double) and claim 3 (single), and similarly claim 10 (double) and claim 11 (single).
5) Are salts, tautomers, and optical isomers included?
Yes. The claim explicitly includes pharmaceutically acceptable salts, tautomers, and optical isomers within the covered compound scope.
References
[1] United States Patent US 11,919,838 (claims provided by user).
