US Patent 10,272,142: C1-Esterase Inhibitor for Acute CNS Attacks in NMOSD
US 10,272,142 claims a treatment method for neuromyelitis optica (NMO) and neuromyelitis optica spectrum disorder (NMOSD) where a patient receives C1-esterase inhibitor (C1-INH) during an active CNS attack at ≥2,000 Units per dose, with a dosing window that tightens in dependent claims to ≤7 days (claim 4), ≤72 hours (claim 5), and ≤24 hours (claim 6) from attack onset. Dependent claims narrow the C1-INH source (human plasma-derived or recombinant), define NMOSD subtypes (including AQP4-negative), and optionally combine C1-INH with standard NMOSD adjuncts such as glucocorticoids (methylprednisolone), rituximab, eculizumab, plasmapheresis, IVIG, mycophenolate, or other intravenous immune therapies.
This is a relatively narrow, attack-timing-and-dose framing over a mechanism (complement/serine protease regulation via C1-INH) that already existed in other inflammatory and complement-mediated indications. The patent’s enforceability and value depend on whether (1) prior art establishes C1-INH use for NMOSD attacks and (2) prior art also discloses the specific ≥2,000 U per dose threshold and the tight initiation windows (≤72 hours and ≤24 hours) coupled to clinical endpoints described as “to pre-attack levels.”
What exactly is claimed?
How is the independent claim framed (claim 1)?
Claim 1 is a method claim with three core limitations:
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Indication and target period
- Treating or delaying progression of NMO/NMOSD
- in a patient “in need of treatment”
- during an active CNS attack.
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Drug identity and dosing quantity
- Administer “one or more doses” of at least 2000 U of C1-INH per dose.
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Clinical effect constraint
- The one or more doses “decreases symptoms of NMO or NMOSD to pre-attack levels.”
Critical legal/technical points
- The “pre-attack levels” language is a functional outcome tied to symptom scales. In enforcement, that term can become a litigation pressure point: it can be argued as subjective or dependent on the measurement protocol used in the accused regimen.
- “During an active CNS attack” plus timing later in dependent claims creates a strong “when” element. That is where many freedom-to-operate analyses will focus: if prior art used C1-INH only for prevention or off-attack intervals, it may avoid the tight combination of purpose and timing.
How do the dependent claims narrow timing, product form, and adjuncts?
Timing windows
- Claim 4: dosing initiated within 7 days from onset of the active CNS attack.
- Claim 5: dosing initiated within 72 hours.
- Claim 6: dosing initiated within 24 hours.
These dependent claims materially tighten the claim scope. If prior art uses C1-INH without such rapid initiation, it may fall outside the dependent claim set, even if it is on-label or mechanistically motivated.
C1-INH source
- Claim 2: C1-INH is human plasma-derived or recombinant.
- Claims 14 and 16: further tie to plasma-derived (claim 14) or recombinant (claim 16).
NMOSD subtype definitions
- Claim 3 is broad and includes, in substance:
- single or recurrent longitudinally extensive transverse myelitis
- bilateral simultaneous or recurrent optic neuritis
- Asian optic-spinal multiple sclerosis
- optic neuritis in systemic autoimmune disease
- optic neuritis or myelitis tied to brain lesions in specific regions (hypothalamus, periventricular nucleus, brainstem)
- NMO-IgG negative NMOSD, including AQP4-antibody-seronegative NMO
This matters because a competitor might attempt to argue non-infringement by using a different diagnostic grouping. Claim 3 blocks that strategy by explicitly incorporating AQP4-seronegative NMO and lesion-defined phenotypes.
Optional adjunct combinations
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Claim 7: method further includes an “adjunct treatment” effective for treating/delaying NMOSD progression.
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Claim 8: C1-INH and adjunct are concurrent or sequential.
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Claim 9: adjunct treatment list includes:
- intravenous immune therapy
- plasmapheresis
- mycophenolate
- rituximab
- eculizumab
- IVIG preparations
- combinations
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Claims 11-13: intravenous immune therapy includes glucocorticoid and specifically methylprednisolone.
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Claims 10, 12, 15, 17: repeat concurrency/sequencing and combination with methylprednisolone tied to plasma-derived or recombinant C1-INH.
From a landscape standpoint, this adjunct scaffolding increases infringement risk: many real-world NMOSD attack protocols already include high-dose glucocorticoids (often methylprednisolone), plasma exchange in steroid-refractory cases, and later B-cell depletion or complement inhibition in prevention settings. The claim makes it easier to argue that adding C1-INH to an already-standard attack regimen meets the “adjunct” wrapper.
The novelty question: what must the patentee have that the prior art lacked?
For validity and enforcement, the key novelty hooks are:
- Indication and timing: C1-INH administered during active CNS attack.
- Dose threshold: ≥2,000 U per dose.
- Rapid initiation windows: within 7 days, then tighter within 72 hours and 24 hours.
- Functional outcome language: “decreases symptoms … to pre-attack levels.”
If any single prior art reference teaches a substantially identical method (same indication context, same “active attack” use, same dose threshold, and same rapid initiation window), that would directly attack claims 4-6. If the dose threshold and initiation window are not disclosed together, those dependent claims become a narrower island of patentable distinction.
What does the competitive freedom-to-operate picture look like?
Who would most likely infringe if C1-INH is used in NMOSD attacks?
The highest-risk actors are:
- Providers administering human plasma-derived or recombinant C1-INH as part of acute NMOSD attack management.
- Developers of C1-INH analogs or alternate C1-INH products if they fall within “C1-INH” as claimed (the claims do not introduce additional chemical constraints beyond C1-INH identity).
- Entities running clinical protocols where investigators start C1-INH rapidly after attack onset and use the described adjunct set, especially methylprednisolone and/or IV immune therapy.
How do the adjunct claims raise practical infringement risk?
Because claim 7 and onward:
- Cover a wide adjunct portfolio.
- Permit concurrent or sequential dosing (claim 8).
In practice, NMOSD acute attack care often uses:
- high-dose IV methylprednisolone first
- plasma exchange in steroid-refractory disease
- rescue immunotherapies in severe cases
If any clinical program combines C1-INH at ≥2,000 U during an attack within ≤72 hours or ≤24 hours, it is the exact fact pattern that the dependent claims are designed to capture.
What are the strongest points for the patentee?
- The claims are attack-specific (not maintenance).
- The claims include explicit dose and timing gates.
- The claim 3 NMOSD definitions are broad across phenotypes and antibody status, including AQP4-seronegative.
These features reduce design-around options based on patient subcategory selection.
What are the highest-friction points for enforceability?
- “Pre-attack levels” is a functional outcome requirement. If clinical documentation uses different assessment tools or does not record “pre-attack” comparative thresholds in a legally direct way, defendants can contest whether the dosing “decreases symptoms … to pre-attack levels.”
- The claims require “during an active CNS attack” which is not always operationalized the same way across clinical practice. Timing and clinical criteria for “onset” can be contested.
- If prior art shows C1-INH used in related neurological or complement-mediated diseases but not explicitly “active CNS attack” in NMOSD with rapid dosing, competitors can argue that only the functional disease mapping differs. That is a validity and claim construction battleground.
Patent landscape analysis: where this sits relative to known NMOSD therapy paradigms
NMOSD care is well established around:
- acute management: high-dose corticosteroids, often IV methylprednisolone; plasma exchange for steroid-refractory disease
- long-term prevention: rituximab and complement inhibition (eculizumab) are prominent, with IVIG and mycophenolate in certain contexts
US 10,272,142 does not replace that backbone. It overlays an additional intervention (C1-INH) into the attack phase and ties it to a defined dose threshold and attack initiation windows. In portfolio strategy terms, that means:
- The claim is positioned to catch incremental add-on use rather than stand-alone C1-INH replacement.
- This increases likelihood that any real-world adoption (in trials or off-label) could create infringement exposure, especially when investigators follow time-to-treatment protocols.
Practical claim-by-claim vulnerability map
Which claims are most likely to be independently defensible?
- Claim 1 is the most general and therefore also the most likely to be attacked by broad prior art.
- However, claim 1 also includes the “pre-attack levels” outcome, which can act as a narrow band if prior art did not report symptom reduction to that benchmark.
Which dependent claims are most likely to be outcome-sensitive?
- Claims 4-6 (timing) are sensitive to prior art protocol details.
- If prior art provides only slower initiation windows, or uses later administration, it may not anticipate those dependent claims.
Which dependent claims are most likely to be design-around-resistant?
- Claim 3 subtype scope is broad and limits patient selection avoidance.
- Claims 7-13 adjunct set captures standard acute NMOSD adjuncts.
Key “design-around” levers and why they may fail
Can a competitor avoid infringement by changing dose?
- The claims require ≥2,000 U per dose. Dropping below that threshold is the simplest lever, but many C1-INH regimens are typically dosed in unit amounts related to weight or fixed dosing; if standard NMOSD-associated protocols already use ≥2,000 U, the design-around becomes difficult.
Can a competitor avoid by delaying administration?
- Claims 4-6 penalize initiation timing within ≤7 days, ≤72 hours, and ≤24 hours.
- A competitor could attempt dosing outside those windows, but claim 1 still covers “during an active CNS attack” without an explicit time limit. So a “delay past 24 hours” strategy might still infringe claim 1 unless it moves administration to a non-attack period or beyond what would be argued as “active attack.”
Can a competitor avoid by excluding certain NMOSD subtypes?
- Claim 3 blocks that by including AQP4-seronegative NMO and multiple phenotypes and lesion patterns. A purely diagnostic-based work-around has limited value.
Can a competitor avoid by omitting adjuncts like methylprednisolone?
- Claim 1 does not require adjuncts. Claims 7 onward only broaden coverage. Omitting adjuncts can avoid dependent claims but not claim 1.
Business implications: what this patent likely tries to capture
From the claim set, US 10,272,142 is drafted to capture C1-INH as an acute attack intervention in NMOSD rather than a prophylactic therapy. The tight “from onset” language suggests the inventors expected a clinical rationale that rapid administration changes outcomes. The optional adjunct language indicates the inventors anticipated standard NMOSD attack care would already include methylprednisolone and similar immune therapies, so C1-INH would be layered in, not used in isolation.
Key Takeaways
- US 10,272,142 claims C1-INH dosing for NMOSD/NMO acute active CNS attacks with a core requirement of ≥2,000 U per dose and a clinical outcome framed as symptom reduction “to pre-attack levels.”
- Dependent claims tighten timing to ≤7 days, ≤72 hours, and ≤24 hours from attack onset, making protocol start time a primary infringement and validity axis.
- The claim set is broad across NMOSD phenotypes, including AQP4-seronegative disease, which constrains diagnostic-based design-around strategies.
- Adjunct claims mirror standard NMOSD acute and immune therapies, including methylprednisolone, rituximab, eculizumab, plasmapheresis, and IVIG, increasing the chance that real-world combined regimens overlap the claim language.
- The main enforceability risk lies in proof issues tied to the functional outcome language (“pre-attack levels”) and operational definitions of “active CNS attack” and “onset.”
FAQs
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Does claim 1 require adjunct therapy?
No. Adjuncts are only introduced in dependent claims (claims 7 onward).
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What is the minimum C1-INH dose recited in the independent claim?
At least 2,000 U of C1-INH per dose (claim 1).
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How fast must treatment start to meet the narrowest dependent timing claim?
Within 24 hours from onset of the active CNS attack (claim 6).
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Are AQP4-seronegative NMOSD patients within scope?
Yes. Claim 3 explicitly includes NMO:AQP4 antibody-seronegative NMO.
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Can C1-INH be plasma-derived or recombinant?
Yes. Claim 2 covers human plasma-derived C1-INH or recombinant C1-INH.
References
[1] US Patent 10,272,142 (claims as provided in prompt).
