US Patent 10,874,663: Scope, Claim Build, and US Landscape for Treatment-Resistant Depression (Bupropion + Dextromethorphan)
What is the core claim scope of US 10,874,663?
US Drug Patent 10,874,663 claims methods of treating treatment-resistant depression (TRD) using a bupropion + dextromethorphan combination at specific dose levels, for at least 8 consecutive days, using a defined release profile and formulation composition constraint (each component is one of the only therapeutically active compounds in the dosage form).
The independent claim set is built around three fixed elements and two “advantage” limitations:
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Patient / disease state
- “a human being in need thereof” for treatment-resistant depression.
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Dose and schedule
- Twice daily option: about 105 mg bupropion hydrochloride + about 45 mg dextromethorphan hydrobromide, administered twice a day for at least 8 consecutive days (and dependent claims expand to 14 and 30 days).
- Once daily option: about 210 mg bupropion hydrochloride + about 90 mg dextromethorphan hydrobromide, administered once a day for at least 8 consecutive days (and dependent claims expand to 14 and 30 days).
- AUC equivalence / substitution option (claim 13): combinations that provide about the same AUC0-24 of bupropion and dextromethorphan as the fixed regimen.
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Dosage form composition limitation
- bupropion and dextromethorphan are the only therapeutically active compounds in the dosage form.
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Release profile requirement
- dosage form is:
- immediate release of dextromethorphan, and
- sustained release of bupropion.
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Comparative effectiveness limitation
- the method is “more effective” than monotherapy control arms using the named comparator dosing.
This architecture creates a claim that is narrower than a broad “use of bupropion + dextromethorphan” patent, but broader than a pure fixed-dose regimen because of the AUC0-24 equivalence substitution and because dose levels are expressed as “about” and allow salt / free-base molar equivalents.
How are the independent claims structured and what do they cover?
Claim 1 (twice daily anchor)
Claim 1 is the primary twice-daily scope anchor.
Required elements (minimum set):
- TRD treatment method for a human
- drug combination twice a day for at least 8 consecutive days
- Combination includes:
- ~105 mg bupropion hydrochloride (or molar equivalent bupropion free base or another salt form)
- ~45 mg dextromethorphan hydrobromide (or molar equivalent dextromethorphan free base or another salt form)
- Both drugs are in a dosage form where:
- bupropion and dextromethorphan are the only therapeutically active compounds
- Dosage form release profile:
- immediate release dextromethorphan
- sustained release bupropion
- Comparative efficacy:
- more effective than 150 mg bupropion hydrochloride alone twice daily for at least 8 consecutive days
Claim 7 (once daily anchor)
Claim 7 mirrors claim 1 but shifts dosing frequency and dose.
Required elements:
- TRD treatment method
- drug combination once a day for at least 8 consecutive days
- Combination includes:
- ~210 mg bupropion hydrochloride (or molar equivalent)
- ~90 mg dextromethorphan hydrobromide (or molar equivalent)
- Dosage form:
- only therapeutically active compounds are bupropion + dextromethorphan
- Release profile:
- immediate release dextromethorphan
- sustained release bupropion
- Comparative efficacy:
- more effective than 210 mg bupropion hydrochloride alone once daily for at least 8 consecutive days
Claim 13 (AUC0-24 equivalence + alternative combinations)
Claim 13 expands scope by:
- listing three combination “forms” that qualify for the method, and
- allowing substitution if AUC0-24 is matched versus the specified twice-daily benchmark regimen.
The claim explicitly covers one of the following:
- (A) ~105 mg bupropion HCl + ~45 mg dextromethorphan HBr twice a day
- (B) ~210 mg bupropion HCl + ~90 mg dextromethorphan HBr once a day
- (C) an amount of bupropion (free base or salt) + an amount of dextromethorphan (free base or salt) that provides:
- about the same AUC0-24 of bupropion and
- about the same AUC0-24 of dextromethorphan
as the ~105 mg / ~45 mg twice-daily regimen
Still required:
- only therapeutically active compounds are bupropion + dextromethorphan
- dosage form release profile:
- immediate release dextromethorphan + sustained release bupropion
- comparative efficacy:
- more effective than 105 mg bupropion alone twice daily for at least 8 days
How do the dependent claims narrow or extend duration and comparators?
Dependent claims add duration and comparator monotreatment arms.
Dose-frequency dependent set (claims 2–6 for twice daily)
- Claim 2: more effective than 45 mg dextromethorphan HBr alone twice daily for at least 8 days
- Claim 3: about 105 mg bupropion HCl + about 45 mg dextromethorphan HBr administered twice daily
- Claim 4: regimen administered for at least 14 consecutive days
- Claim 5: regimen administered for at least 30 consecutive days
- Claim 6: combination administered twice daily for at least 30 days
Dose-frequency dependent set (claims 8–12 for once daily)
- Claim 8: more effective than 90 mg dextromethorphan HBr alone once daily for at least 8 days
- Claim 9: about 210 mg bupropion HCl + about 90 mg dextromethorphan HBr administered once daily
- Claim 10: regimen administered for at least 14 consecutive days
- Claim 11: regimen administered for at least 30 consecutive days
- Claim 12: combination administered once daily for at least 30 days
Additional dependent narrowing within claim 13 (claims 14)
- Claim 14: more effective than 45 mg dextromethorphan alone twice daily for at least 8 days
What dosage-form and composition features matter most for freedom-to-operate?
The non-negotiable technical hooks in the claims are:
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Immediate release dextromethorphan + sustained release bupropion
- If either component’s release profile deviates from this split, the method claim’s “dosage form is formulated…” limitation is not met as written.
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Only bupropion + dextromethorphan are therapeutically active
- A formulation with additional therapeutically active agents (even if clinically inactive for TRD but pharmacologically active) risks falling outside this “only therapeutically active” constraint.
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Salt and free-base molar equivalents
- “about X mg of [HCl/HBr] or a molar equivalent amount” broadens the claim to cover alternative salt/free-base choices that meet molar equivalent substitution.
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Dose ceiling logic is controlled by “about” and comparator logic
- The claim’s comparative advantage is defined against monotherapies at specific doses:
- twice daily comparator in claim 1: 150 mg bupropion HCl alone twice daily
- once daily comparator in claim 7: 210 mg bupropion HCl alone once daily
- twice daily comparator in claim 2/14: 45 mg dextromethorphan HBr alone twice daily
- once daily comparator in claim 8: 90 mg dextromethorphan HBr alone once daily
- A product that changes dose might still fit if the claim language permits it (“about”), but the “more effective than” test is tied to these specific comparator regimens.
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AUC0-24 equivalence substitution
- Claim 13’s AUC matching expands beyond a single mg/administration scheme, capturing reformulations that hit exposure targets versus the ~105 mg/~45 mg twice-daily benchmark.
How broad or narrow is the claim set in practical terms?
Coverage matrix (method scope, as claimed)
| Claim basis |
Dosing frequency |
Target amounts (as claimed) |
Duration floor |
Release profile required |
Comparator “more effective” anchor |
| Claim 1 |
Twice daily |
~105 mg bupropion HCl + ~45 mg dextromethorphan HBr |
≥8 days |
IR dextromethorphan; SR bupropion |
vs 150 mg bupropion HCl alone BID |
| Claim 7 |
Once daily |
~210 mg bupropion HCl + ~90 mg dextromethorphan HBr |
≥8 days |
IR dextromethorphan; SR bupropion |
vs 210 mg bupropion HCl alone QD |
| Claim 13 |
Either listed regimen or AUC-matched alternative |
~105/45 BID or ~210/90 QD or AUC0-24 match to ~105/45 BID |
≥8 days |
IR dextromethorphan; SR bupropion |
vs 105 mg bupropion alone BID |
| Dependents (2,8,14) |
N/A |
Same combo |
≥8 days (or longer via others) |
Same |
adds dextromethorphan monotherapy comparators |
Interpretation of breadth drivers
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Narrowness reducers:
- TRD definition is implied but not exhaustively defined in the claim text; still, it requires that the method targets “treatment-resistant depression.”
- The dosage form must have the defined split release.
- Formulation must have only two therapeutically active compounds.
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Breadth expanders:
- “about” for doses and molar equivalents for salts/free base.
- AUC0-24 matching in claim 13 captures reformulations even if the mg and dosing schedule differ, as long as exposure matches the benchmark.
What does the claim language imply about prior art and obviousness arguments?
The patent is drafted as a combination efficacy + formulation-release combination, with comparative superiority limitations against monotherapies at defined doses.
That design pushes invalidity arguments toward:
- Reaching all elements: finding prior art that already teaches:
- TRD treatment with bupropion + dextromethorphan combination,
- at those dose ranges,
- with IR dextromethorphan and SR bupropion,
- and showing superiority versus specific bupropion or dextromethorphan monotherapy schedules.
- Reframing “more effective”:
- If prior art claims TRD improvements but does not show comparative superiority over the exact comparator dosing, that may be a distinguishing path.
- AUC0-24 matching:
- Prior art that uses alternative dosing but yields comparable exposure could map to claim 13’s AUC substitution if it also uses the split-release formulation design.
How should this patent be mapped in a US patent landscape view?
Given the information provided is only the claim text for US 10,874,663, the landscape mapping must be built from claim-structure, not from external bibliographic verification.
Landscape nodes to expect around this claim (based on its hooks)
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Formulation patents for IR dextromethorphan + SR bupropion
- These are typically the hardest-to-design-around because they are tied to dosage form release design and “only therapeutically active” limitations.
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Combination therapy patents for bupropion + dextromethorphan
- These may exist in both method and product forms, but this patent’s method claims require:
- TRD,
- split release,
- specific dose schedules or AUC matching.
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Regimens in depression and TRD subclasses
- Many depression patents exist; few will match “treatment-resistant depression” plus this exact dose/exposure/formulation architecture.
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Bioequivalence and AUC matching as reformulation strategy
- Claim 13 explicitly anticipates reformulations and substitutes that match systemic exposure, which is a typical design point in later product generations.
Practical litigation risk hotspots
- If an ANDA or 505(b)(2) product uses an IR bupropion or SR dextromethorphan approach, it may fall outside the release profile element.
- If it includes any additional therapeutically active agent, it may fall outside the “only therapeutically active compounds” element.
- If it matches exposure (AUC0-24) but not dosing, claim 13 still creates pathway risk unless the exposure matching is avoided and the release profile differs.
What are the claim design implications for product design (design-around vs capture)?
Elements that are hardest to design around
- IR dextromethorphan + SR bupropion combined in one dosage form with only those two active compounds.
- AUC0-24 equivalence substitution that can capture alternative dosing strengths/schedules.
Elements that are design variables
- Dose expressed as “about” and as molar equivalents. A product can attempt to move outside the “about” region or avoid the exposure match.
- Comparative efficacy limitation. A product could attempt to prevent the “more effective than comparator” evidence mapping by:
- changing clinical trial outcomes, or
- targeting a different indication (though method claims specify TRD treatment).
Summary of claim coverage and key decision points
- US 10,874,663 is a TRD treatment method patent built on:
- bupropion + dextromethorphan combination,
- defined dose levels (two schedules) or AUC0-24 matching,
- dosage form release split (IR dextromethorphan, SR bupropion),
- two-drug-only therapeutically active composition,
- superiority assertions versus bupropion and dextromethorphan monotherapy at specified doses and schedules.
- The largest practical risk sits with any product that matches:
- split-release,
- two-active-only formulation,
- and either the fixed dose regimens or the AUC0-24 match.
Key Takeaways
- The patent claims TRD treatment methods using a bupropion + dextromethorphan combination with defined dosing regimens (twice daily ~105/45 mg; once daily ~210/90 mg) for at least 8 days.
- Coverage is constrained by dosage form engineering: immediate release dextromethorphan and sustained release bupropion in a dosage form where only these two compounds are therapeutically active.
- Claim 13 materially expands scope by capturing AUC0-24-matched reformulations to the ~105/45 twice-daily benchmark, even if dosing differs.
- The claims include comparative “more effective” limitations against specific bupropion and dextromethorphan monotherapy dose/schedule controls, shaping enforcement evidence needs.
- From an R&D/design-around perspective, release-profile and AUC match are the dominant technical levers; extra active compounds and deviating from split-release provide potential exclusion paths.
FAQs
1) Does US 10,874,663 protect the drug product itself or only the method?
The claims provided are method of treating TRD claims, with explicit limitations about the dosage form (release profile and active-compound composition). Product protection depends on the patent’s product claims, if any, not included in the provided text.
2) What exact dose combinations are claimed for TRD?
- Twice daily: about 105 mg bupropion HCl + about 45 mg dextromethorphan HBr
- Once daily: about 210 mg bupropion HCl + about 90 mg dextromethorphan HBr
Claim 13 also allows AUC0-24 equivalents to the twice-daily benchmark.
3) What release profile does the claim require?
The dosage form must provide:
- immediate release (IR) of dextromethorphan
- sustained release (SR) of bupropion
4) Can salt forms fall under the claims?
Yes. Each drug is covered as the named salt or a molar equivalent amount of the free base or another salt form.
5) What monotherapy comparators are used for the “more effective” limitation?
Key comparators in the claim set include:
- bupropion HCl alone at 150 mg BID (claim 1) and 210 mg QD (claim 7)
- dextromethorphan HBr alone at 45 mg BID (claims 2, 14) and 90 mg QD (claim 8)
References
[1] Provided claim text for US Drug Patent 10,874,663 (user-supplied).
