United States Patent 11,253,494: Scope, Claim Coverage, and US Patent Landscape for GHB-Divalproex Concomitant Dosing
Executive summary: US Patent 11,253,494 is a US method-of-treatment patent directed to reducing the dose of gamma-hydroxybutyrate (GHB) (or a GHB salt) when administered concomitantly with divalproex sodium, including quantitative dose-reduction bands relative to a “recommended daily dosage amount” used without divalproex. The claim set centers on (i) specific proportional reductions (about 15% to about 35% lower; with dependent fallback to ~15% to ~30% and ~20%), (ii) absolute daily dose ranges anchored to 4.5 g to 9 g (and narrower cutoffs like <4.5 g, <3.6 g, <3 g), (iii) titration and split-dose variants (two equal doses; each dose below 2.25 g in one dependent claim), and (iv) interaction-mediated justification using PK/PD measurements and validated sleepiness endpoints (Cognitive Drug Research tasks, Karolinska Sleepiness Scale). From a landscape perspective, the patent is narrower than broad GHB use patents because it requires the divalproex concomitancy and the specific quantitative reduction logic tied to an “absence of concomitant administration” reference.
Important scope note (how the claims read in business terms): The independent claims are not “any reduction when coadministered.” They are reductions that are defined relative to a comparator dosing regime “in the absence of concomitant administration of divalproex sodium,” and the comparator is further bounded to prescribed daily dosage amounts (4.5 g to 9 g in the main independent claim set; and 1 g to 6 g in a second independent claim block). That structure narrows both infringement design-around opportunities and validity challenges, because practicing outside the recited proportional and absolute ranges likely avoids literal coverage.
What does US Patent 11,253,494 claim for GHB dosing with divalproex sodium?
Core claim concept (independent-method coverage): A clinician method for treating a patient receiving divalproex sodium concomitantly with GHB, where the daily GHB dose is reduced by ~15% to ~35% compared with the recommended daily dosage amount in the absence of concomitant divalproex, with the “absence” reference dose between 4.5 g and 9 g.
Claim-set architecture
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Main independent claim (Claim 1):
- Concomitant divalproex + GHB (or salt)
- Daily GHB dosage reduced about 15% to about 35% lower
- Comparator “no-divalproex” recommended dose: 4.5 g to 9 g
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Dependent refinement hooks (Claims 2–12):
- Absolute reductions: less than 4.5 g (Claim 2), less than 3.6 g (Claim 3)
- Split dosing: two equal doses (Claim 4); one of the two doses <2.25 g (Claim 5)
- Narrower band: about 15% to about 30% (Claim 6); about 20% (Claim 7)
- Specific comparator points: comparator equals 4.5 g (Claim 8) or 6–9 g (Claim 9), 7.5–9 g (Claim 10), or 9 g (Claim 11)
- Dose determined using “manufacturer’s recommended daily dosage amount” (Claim 12)
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Second independent claim block (Claim 14):
- Same overall structure but comparator reference is between 1 g and 6 g (instead of 4.5–9 g)
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Third independent claim block focused on adverse effects (Claim 20):
- Reducing adverse effects caused by the combination (concomitant divalproex)
- Same quantitative reduction band and comparator 4.5–9 g
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Fourth independent claim block focused on PK/PD compensation (Claim 25):
- Reduced daily GHB dose to a concomitant divalproex patient
- Reduced dose “compensates for PK and/or PD changes caused by divalproex”
- Comparator again bounded to 4.5–9 g
- Adds measurement methods for support/definition of the interaction rationale (Claims 26–27)
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Patient condition limitation appears as an additional narrowing element:
- Claims 13 and 19 and 24 and 30 state the patient suffers from excessive daytime sleepiness.
What precise quantitative parameters drive infringement risk?
From a “design-around” perspective, the numeric elements create bright-line thresholds:
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Proportional reduction: “about 15% to about 35% lower”
- Explicit dependent windows:
- about 15% to about 30% (Claim 6)
- about 20% (Claim 7)
- about 15% and about 30% (Claim 21)
- about 20% (Claims 22 and 29)
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Comparator band (“absence of concomitant divalproex”)
- Claim 1: 4.5 g to 9 g
- Claim 14: 1 g to 6 g
- Claim 20 and Claim 25: 4.5 g to 9 g
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Absolute daily dose cutoffs
- Claim 2: <4.5 g
- Claim 3: <3.6 g
- Claim 15: (within Claim 14 framework) <3 g
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Split dosing structure
- Two equal doses (Claim 4 and Claim 16)
- One of the two doses <2.25 g (Claim 5)
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Treatment intent / outcome framing
- “suffering from excessive daytime sleepiness” (Claims 13/19/24/30)
- “reducing adverse effects caused by the combination” (Claim 20 and dependents)
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PK/PD measurement definitions
- PD measurement via CDR system tasks or KSS (Claim 26)
- PK parameters including plasma concentration, Cmax, Cn, C24, Tmax, AUC (Claim 27)
Practical consequence: A GHB prescriber who reduces dose outside the proportional band, outside the referenced comparator range, or who does not practice in a context meeting the “concomitant divalproex” requirement, is less likely to fall within literal infringement.
Which patients and indications are covered by Claim 11,253,494?
Indication-limited embodiments
- The patent includes dependent claims explicitly limiting the patient to excessive daytime sleepiness (EDS) (Claims 13, 19, 24, 30).
- Claims 1, 14, 20, and 25 are not stated in your excerpt as EDS-limited in the independent claim text you provided. Those independent blocks can still be argued as covering any patient receiving concomitant divalproex and GHB under the dose-reduction scheme, depending on how “treating a patient” is interpreted in the specification and prosecution record.
Commercially relevant read-through for EDS
- If GHB is being used for disorders characterized by EDS (classically narcolepsy/cataplexy spectrum uses for sodium oxybate family products), EDS-dependent claims reduce ambiguity around clinical relevance and support enforcement tied to the intended population.
How do Claims 1 vs 14 vs 20 vs 25 differ in scope?
Claim 1 (main: 4.5–9 g comparator)
- Broadest comparator: recommended absence-of-divalproex dose 4.5 g–9 g
- Broad proportional reduction: 15%–35% lower
- Dependent claims narrow to absolute reductions, split dosing, and specific proportional targets.
Claim 14 (secondary: 1–6 g comparator)
- Same “concomitant divalproex + reduced GHB” frame but comparator range is 1–6 g
- Dependent cutoffs: <3 g daily; two equal doses; about 20% lower; manufacturer recommended daily dosage; EDS-limited.
Claim 20 (adverse effects reduction framing)
- The method is to reduce adverse effects caused by the combination
- Same proportional and comparator range (4.5–9 g for the absence reference)
- Dependent claims specify “about 15% and about 30% lower” (Claim 21) and “about 20% lower” (Claim 22), plus EDS-limited.
Claim 25 (PK/PD compensation mechanism)
- Defines reduction as compensating for PK and/or PD changes
- Adds measurable endpoints/parameters in dependents:
- PD: CDR tasks or KSS
- PK: concentration metrics and exposure metrics
- Comparator again 4.5–9 g
Infringement landscape implication
- If an accused product labels or implements a dose adjustment when used with divalproex, they may still avoid Claim 25 if they do not “compensate for PK/PD changes” in a way that matches how the claim is interpreted, but they may still be caught by Claims 1/20 if the actual implemented dosage reduction matches the quantitative limitations.
What is the functional meaning of “recommended daily dosage amount in the absence of concomitant administration”?
This comparator phrase is pivotal because it can be attacked or leveraged:
- Potential enforcement lever: Claim 12 explicitly covers dosing at the “manufacturer’s recommended” absence-of-divalproex dose. If a manufacturer recommends a starting daily dosage band for GHB without divalproex, the claim ties directly to that reference.
- Potential litigation issue: “recommended” could be argued as context-dependent (labeling for specific populations, titration stages, or dosing schedules). But the claims you provided still anchor the comparator to fixed numeric ranges (1–6 g or 4.5–9 g), which limits that ambiguity.
Claim risk mapping
- If clinical practice uses reduced doses with divalproex that correspond to a reduction of, say, 10% relative to the label (without divalproex), it is outside the “about 15% to about 35% lower” core range and may avoid coverage.
- If practice reduces by 15%–35% but relative to a comparator outside the claimed “absence” band, literal infringement is less likely.
What dependent claims most constrain dosing regimens (split dosing, absolute thresholds)?
Split dosing claims
- Claim 4 and Claim 16 require dosing split into two equal doses.
- Claim 5 adds that the first or second dose is <2.25 g (when applying the Claim 4 framework).
This matters for enforcement against specific titration schedules. If an accused regimen uses once-daily dosing (or three or more administrations) it may fall outside these specific dependent claim constraints, though still potentially within independent claim protection if the independent claims do not require split dosing.
Absolute cutoffs
- <4.5 g (Claim 2)
- <3.6 g (Claim 3)
- <3 g (Claim 15)
These can function as practical switches in design-around: if a competitor’s regimen uses a reduction that lands just above the cutoffs, they may avoid literal dependent coverage while still needing to consider whether the broader independent proportional range is still met.
How do PK/PD measurement dependents shape Claim 25’s scope?
PD measurement dependents
- Claim 26 ties to PD interactions measured by:
- Cognitive Drug Research (CDR) system tasks
- Karolinska Sleepiness Scale (KSS)
PK parameter dependents
- Claim 27 specifies PK parameters from:
- plasma concentration
- Cmax
- Cn
- C24
- Tmax
- AUC
Interpretive business effect
- These dependents are strong evidence that the patent’s prosecution record likely focused on measurable interaction outcomes with divalproex, not just empiric dose reduction.
- For enforcement, they support an argument that the claimed method is not arbitrary; it is grounded in objective interaction signals. For challenges, they define what “PK/PD changes” are expected to look like in the claim framework.
What does the US patent estate likely look like around US 11,253,494 (GHB + divalproex dose interaction)?
Only the claim text is provided here. A full estate map requires identifying co-pending continuations, related priority applications, and any other US/WO family members. Those items are not present in your input, so a complete landscape cannot be produced without non-provided metadata.
What can be stated from the claims alone is the likely portfolio strategy reflected by claim structure:
- One or more independent claims address:
- quantitative dose reduction bands tied to concomitant divalproex
- multiple comparator bands (4.5–9 g and 1–6 g)
- multiple claim rationales: treatment of EDS, reducing adverse effects, and compensating for PK/PD interactions
- Dependent claims add enforcement fallbacks:
- split dosing limitations
- absolute thresholds
- specific proportional points (~15%, ~20%, ~30%)
- specific measurement endpoints and PK parameters
This is typical of an interaction/potential label-change portfolio: the patent is framed to capture real-world clinical dose reductions rather than only one specific clinical trial protocol.
When does the patent potentially expire, and how long can it block generic entry?
A precise expiration timeline (utility term end, PTA adjustments, and any regulatory exclusivity interplay) depends on filing date, priority date, and whether the patent has PTA. Those details are not provided. Without them, an accurate expiration date cannot be stated.
Orange Book status and FDA exclusivity: what is the linkage for US 11,253,494?
Orange Book listing for a method-of-treatment patent is highly product-specific. Your input does not include the drug product name, NDA/ANDA/BLA reference product, or Orange Book entries. Without those, Orange Book status cannot be correctly mapped.
How strong is patent coverage for competitors reducing GHB dose with divalproex?
Strength factors derived from claim scope
- Quantified ranges reduce interpretive drift and improve enforceability against dose-adjustment practice.
- Multiple claim rationales increase the chance that an accused regimen matches at least one claim block:
- direct treatment dosing
- adverse effects reduction framing
- PK/PD compensation rationale
- Comparator reference to “recommended daily dosage amount” creates a link to labeling/manufacturer recommendations, which is often central in litigation.
Weakness factors derived from claim scope
- Narrow numeric windows can enable “near-miss” design-around if a regimen targets a reduction just outside the proportional band or outside the comparator range.
- Dependents tied to measurement methods (CDR tasks, KSS, PK parameters) can be used to narrow interpretation of Claim 25, depending on how courts treat mechanism language in method claims.
Generic launch scenarios: what dose-adjustment facts determine infringement risk?
For method-of-treatment claims in the US, infringement risk typically tracks:
- whether the prescriber administered GHB while the patient was concomitantly administered divalproex
- whether the administered daily amount is within the claimed proportional reduction and comparator band
- whether the patient fits any dependent limitations (EDS-limited claims)
- the dosing schedule structure (two equal doses; dose <2.25 g in dependent claims)
Risk tiers (conceptual)
- Highest risk: regimen matches both concomitancy and falls squarely in proportional reduction band with comparator and daily dose ranges.
- Medium risk: proportional reduction matches but dosing falls outside one of the comparator bands or absolute cutoffs for dependent claims.
- Lower risk: regimen uses a different proportional reduction magnitude or avoids matching the comparator range.
- Case-specific: whether courts treat “compensates for PK/PD changes” as requiring proof of causality in the specific patient versus broader therapeutic intent.
Key Takeaways
- US 11,253,494 is a method-of-treatment patent focused on dose reduction of GHB (or salts) when used concomitantly with divalproex sodium, using quantified reduction bands relative to a defined “recommended” comparator absence-of-divalproex dose.
- The claim set spans two comparator ranges (1–6 g and 4.5–9 g) and multiple enforcement angles: treatment of a patient (including EDS-dependent claims), reducing adverse effects, and PK/PD-compensated dosing.
- Enforcement strength comes from the numeric limits (about 15%–35% lower, including ~20% and narrower subranges) plus anchors to specific daily dose bands and some operational dosing constraints (split dosing).
- Design-around opportunities depend on whether an alternative regimen changes the magnitude of reduction or the reference comparator range, and whether it avoids matching dose cutoffs and schedule limitations in the dependent claims.
FAQs
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How do “about 15% to about 35% lower” terms impact design-around dosing decisions?
They force competitors to target reductions that land outside the proportional band, but “about” creates a factual inquiry around rounding and variability; litigation turns on the implemented reduction versus the claimed range.
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Does split dosing matter if an accused regimen uses once-daily administration?
Split dosing is required only for specific dependent claims (e.g., two equal doses). Independent coverage can still apply if the independent claims do not impose a split-dose requirement.
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What is the role of “manufacturer’s recommended daily dosage amount” in the claim?
It operationalizes the comparator reference, tying the reduction calculation to labeled or manufacturer guidance used for the absence-of-divalproex regimen.
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How do CDR system tasks and KSS limit Claim 25’s application?
They appear in dependent claim dependents supporting the PK/PD rationale, shaping evidentiary support and potential narrowing if the mechanism language is construed strictly.
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Can a clinician avoid infringement by using a different divalproex dosing schedule?
The claims require concomitant administration of divalproex, but they do not quantify divalproex dose. Avoidance would more likely rely on changing GHB dose reduction magnitude and/or comparator alignment, not on divalproex schedule alone.
References
No sources were cited because no bibliographic metadata (publication number, filing/priority dates, application family, assignee, prosecution documents, FDA labeling, NDA/ANDA linkage) was provided beyond claim text.
