Scope and Claims Analysis for US Patent 9,829,495 (Cushing’s syndrome + ACTH differential diagnosis using glucocorticoid receptor antagonists)
US 9,829,495 claims a diagnostic-therapeutic workflow that combines (1) administration of a glucocorticoid receptor antagonist (GRA) at a dose designed to elicit a defined pituitary ACTH response and (2) concurrent ACTH sampling from inferior petrosal venous sinuses (IPVS) and a peripheral vein followed by a specific ACTH ratio threshold (>3) to distinguish Cushing’s disease from ectopic ACTH secretion. The patent is method-of-treatment and method-of-diagnosis intertwined, with broad claim coverage to the use of any GRA meeting functional and timing requirements, plus narrower dependent claim coverage to particular GRAs (including mifepristone) and specific steroidal and nonsteroidal antagonist chemotypes.
What is US Patent 9,829,495 and what does it claim?
Core claim concept (independent claim 1):
A method that concurrently (a) treats Cushing’s syndrome and (b) differentially diagnoses ACTH-dependent Cushing’s syndrome between:
- ectopic ACTH syndrome, and
- Cushing’s disease,
using an adrenal axis “challenge” induced by a glucocorticoid receptor antagonist.
Claim 1 step-by-step (functional workflow)
Claim 1 requires the following elements in sequence:
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Select patient with:
- Cushing’s syndrome
- elevated ACTH levels.
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Administer a GRA dose sufficient to increase ACTH from the pituitary gland by at least two-fold in persons with normal hypothalamus-pituitary-adrenal (HPA) function.
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Wait at least 2 hours.
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Obtain paired venous measurements:
- ACTH concentration ratio derived from:
- fluid from left or right inferior petrosal venous sinus (IPVS)
- fluid from a peripheral venous sample.
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Apply diagnostic threshold:
- ACTH ratio > 3
defined as (ACTH concentration from inferior venous sinus sample) / (ACTH concentration from peripheral venous sinus sample).
If the ratio is greater than 3, it is diagnostic of Cushing’s disease.
Claim 18 (independent claim, more measurement-centric)
Claim 18 repeats essentially the same technical constraints but frames the act as:
- determining the ACTH ratio after administering the GRA and
- using the ratio (>3) as indicative of Cushing’s disease.
Claim 18 is narrower in emphasis (measurement first, “concurrently treating” included in preamble), but it preserves the same pivotal parameters:
- GRA must be dosed to produce ≥2-fold pituitary ACTH increase (in normal HPA function persons),
- sampling involves IPVS (left or right) and peripheral vein,
- diagnosis uses ratio >3,
- venous samples taken after at least 2 hours from GRA dosing.
Key legal characterization
Even though “ACTH ratio > 3” reads like diagnostics, both independent claims are drafted as methods with therapeutic (or “concurrently treating”) language. That affects enforcement posture:
- The method is not limited to interpretive laboratory steps; it includes patient selection, dosing, and timing, which typically strengthens infringement theories against procedural “workarounds.”
Which parts of the claim are truly limiting versus broad?
Limiting features that drive claim scope
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GRA administration with functional pituitary response requirement
- Not “any GRA.” The dose must be sufficient to cause ≥2-fold ACTH increase from pituitary in persons with normal HPA function.
- This functional recitation can be satisfied by demonstrating that the regimen meets that biological effect.
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Timing
- “waiting for at least two hours” (claim 1) and at least two hours prior to removal of venous samples (claim 18).
- Sampling outside that window may avoid literal coverage.
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Sampling anatomy
- must include inferior petrosal venous sinus (left or right) and a peripheral venous sample.
- A different venous site strategy could fall outside.
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Specific ratio metric and threshold
- ratio computed as IPVS ACTH divided by peripheral ACTH.
- threshold is strictly greater than 3 (not ≥3).
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Patient phenotype
- Cushing’s syndrome and elevated ACTH.
- Differential diagnosis is specifically between ectopic ACTH syndrome and Cushing’s disease.
Broad features
- Any GRA meeting the functional dosing requirement
- The independent claims do not lock to a particular molecule.
- “Left or right” IPVS
- Peripheral vein not fixed in claim 1
- Dependent claim 2 specifies jugular.
How does claim 1 compare to claim 18 in scope and infringement risk?
Claim 1: broader on “concurrently treating” framing and includes an explicit “selecting a patient” sequence plus the step order culminating in ratio diagnosis.
Claim 18: more directly covers the “determining ACTH concentration ratio” act, still requiring:
- GRA dosing meeting the ≥2-fold functional pituitary increase,
- ≥2 hour interval,
- IPVS (left/right) + peripheral sampling,
- ratio >3 indicative of Cushing’s disease.
Practical effect: both capture the same experimental/clinical protocol. Claim 18 is likely to be asserted even when an accused party contests “treatment” intent, because its operative step is the measurement-and-diagnosis protocol after a GRA challenge.
What patents protect the GRA reagent aspect (mifepristone and other GRAs)?
US 9,829,495 contains dependent chemistry limitations. These carve out “implementation-specific” coverage that is useful for targeting product-specific or class-specific substitutes.
Dependent claim 7
Dependent claims 5–9: steroidal antagonist embodiments
These claims target GRAs with particular steroid backbones and phenyl substitutions, including:
- claim 5: steroidal backbone with at least one phenyl-containing moiety in the 11-β position,
- claim 6: that moiety is dimethylaminophenyl,
- claim 8–9: specify further named structures (including two distinct steroidal compounds explicitly enumerated).
Dependent claims 10–17: nonsteroidal antagonist embodiments
- claim 10: GRA has a non-steroidal backbone,
- claim 11: backbone is cyclohexyl pyrimidine,
- claim 12: extensive structural definition for that cyclohexyl pyrimidine (variable substitution patterns, salts included),
- claim 13–14: fused azadecalin embodiments,
- claim 15–17: heteroaryl ketone fused azadecalin or octahydro fused azadecalin, with formula-defined variable substituents.
Practical coverage logic:
If a competitor uses a different GRA chemotype but still conforms to:
- ≥2 hour interval,
- ≥2-fold pituitary ACTH response dosing,
- IPVS/peripheral sampling, and
- ratio >3 diagnostic rule,
they can infringe claim 1/18 even without matching dependent chemistry claims. The dependent claims matter most when:
- enforcing against a specific GRA supplier,
- arguing validity via structural embodiment clarity,
- or when an accused protocol is close but may fail the broad “any GRA” requirement, yet matches a specified scaffold.
What formulations and device steps are (not) claimed?
Not claimed in the provided text:
- dosage form (tablet vs IV),
- method of manufacturing,
- assay kits,
- ACTH immunoassay platforms,
- sample handling (centrifugation, storage, transport time),
- normalization to cortisol or other markers.
The patent focuses on:
- patient selection
- GRA dosing
- time interval
- where samples are taken (IPVS + peripheral)
- how results are interpreted (ratio >3)
That makes it more enforceable against “clinical protocol” implementations than formulation developers.
How “strong” is the patent’s practical enforceability based on claim structure?
Strength factors
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Protocol-driven infringement surface
- To infringe, a party must implement a fairly specific combination of dosing, timing, sampling sites, and ratio threshold.
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Clear numeric diagnostic threshold
- “greater than 3” is concrete for assay interpretation and adjudication.
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Functional dosing constraint
- “dose sufficient to increase pituitary ACTH by at least two fold” provides flexibility in reagent selection.
Potential vulnerability factors (structural)
These are not legal conclusions, but they show where claim construction disputes typically arise:
- The phrase “persons with normal HPA function” invites debates on how the dosing sufficiency is established and evidenced.
- “Concurrently treating” may be treated as preamble-like in some contexts, though claim 18 keeps the diagnostic measurement as the operative step.
Where does the patent sit within the broader Cushing’s disease diagnostic patent landscape?
At a high level, the field includes:
- inferior petrosal sinus sampling (IPSS) diagnostic methods,
- modifications to improve sensitivity/specificity for Cushing’s disease vs ectopic ACTH secretion,
- pharmacologic stimulation or suppression paradigms using ACTH, CRH, desmopressin, GR antagonists, etc.,
- and procedural timing/ratio thresholds.
US 9,829,495 is distinguishable because it is anchored to:
- a glucocorticoid receptor antagonist challenge and
- an IPVS-to-peripheral ACTH ratio >3 after that challenge and at least two hours later.
This combination positions the patent as a protocol improvement rather than a wholly new sampling device or assay platform.
What generic entry risks exist if GRAs (or competing GRAs) are involved?
Because the patent’s independent claims require a specific clinical protocol including:
- selecting ACTH-elevated Cushing’s patients,
- administering a GRA with a functional pituitary ACTH response requirement,
- waiting ≥2 hours,
- performing IPVS and peripheral venous sampling,
- applying ratio >3 to diagnose Cushing’s disease,
the “generic entry risk” is less about generic drug manufacturing and more about whether the clinical workflow is adopted with a given antagonist.
If a competitor uses mifepristone (or a specified GRA scaffold) but does not follow:
- the ≥2 hour window, or
- the >3 ratio threshold, or
- the IPVS + peripheral sampling scheme,
they can reduce direct infringement exposure.
If a competitor uses any different GRA but still:
- meets the functional ≥2-fold pituitary ACTH response dosing,
- follows the sampling and ratio rule,
then the “GRA molecule” substitution is not a safe harbor.
What matters for litigation strategy given claim drafting?
For plaintiffs/enforcement
- Use claim 1/18 to argue infringement based on the entire clinical protocol.
- Anchor to ratio computation and sampling location requirements.
- Use dependent claims to strengthen specificity if the accused provider uses:
- mifepristone, or
- specific steroidal/nonsteroidal chemotypes enumerated.
For defendants
- Focus defenses typically center on:
- whether the dosing regimen actually meets “≥2-fold pituitary ACTH increase” as required,
- whether samples were taken after at least two hours,
- whether the ratio threshold was strictly “greater than 3,”
- and whether sampling included inferior petrosal venous sinus plus peripheral.
These are the claim’s most operational elements.
Patent landscape mapping (what can be concluded from the provided record only)
This analysis is limited to the claim text you provided for US 9,829,495. It does not include the rest of the US patent publication record, family members, priority dates, prosecution history, or related patents of record. Without those, a complete “multi-patent estate” map cannot be constructed from the text alone.
What can be reliably stated from the claim set:
US 9,829,495 covers multiple claim layers
- Protocol level: independent claims 1 and 18 cover diagnosis + concurrent treatment protocol.
- Reagent level: dependent claims narrow to:
- mifepristone,
- steroidal GRAs with defined phenyl/moiety and named structures,
- nonsteroidal GRAs with defined backbones and formulae.
- Sampling level: dependent claim 2 narrows peripheral sample to jugular vein.
- Sampling timing refinement: dependent claim 4 includes first and second sampling 5–10 minutes apart.
The estate is likely to be method-focused rather than device/formulation-focused
Given the lack of claimed pharmaceutical compositions beyond antagonist identification, enforcement will likely track protocol adoption in specialist centers.
Key Takeaways
- US 9,829,495 claims a GRA-challenge IPVS diagnostic protocol for ACTH-dependent Cushing’s syndrome: administer a glucocorticoid receptor antagonist, wait ≥2 hours, sample inferior petrosal venous sinus + peripheral vein, and diagnose Cushing’s disease when IPVS/peripheral ACTH ratio is >3.
- Claim 1 and claim 18 cover essentially the same technical protocol, with claim 18 more explicit on the measurement/differential diagnosis steps.
- Dependent claims add coverage to specific antagonist classes and embodiments, including mifepristone and multiple steroidal and nonsteroidal GRAs with detailed structural limitations.
- The patent’s infringement surface is clinical workflow dependent: protocol adherence is central (dose functional effect, timing, sampling sites, and ratio threshold).
FAQs
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Does US 9,829,495 require both left and right inferior petrosal venous sinuses sampling?
No. The claims specify fluid from either the left or right inferior petrosal venous sinus.
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Is the diagnostic threshold “ACTH ratio greater than 3” strict or does it include 3?
The claim language is “greater than 3,” which excludes an exact value of 3.
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What peripheral vein is required?
Claim 1 permits a peripheral venous sample generally; claim 2 narrows it to a jugular venous sample.
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Can a shorter than two-hour interval avoid infringement?
The independent claims require waiting at least two hours (or administering at least two hours prior to removal of venous samples).
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If a different glucocorticoid receptor antagonist is used, does the patent still apply?
The independent claims can apply to any GRA as long as the administered dose is sufficient to increase pituitary ACTH by at least two-fold in persons with normal HPA function, with the rest of the protocol followed.
References (APA)
- United States Patent No. 9,829,495. (Claims text provided in prompt).
