Scope and claims of US Patent 10,183,002 (glyceryl tri[4-phenylbutyrate] dosing method for UCD patients based on a single fasting ammonia value)
US Patent 10,183,002 claims a tightly specified oral dosing algorithm for glyceryl tri[4-phenylbutyrate] (GT4PB; PB-GT) in urea cycle disorder (UCD) patients. The core claim is a method of treating a UCD subject using (i) an initial GT4PB dose, (ii) a single fasting plasma ammonia measurement after a defined time to reach steady state, and (iii) an adjusted dose increased only when fasting ammonia exceeds a threshold linked to each lab’s “upper limit of normal” (ULN), with an explicit probability statement for patients whose fasting ammonia falls between 0 and 0.5 ULN. Dependent claims narrow the steady-state time windows and add specific lab thresholds and fasting collection parameters.
Which patents protect US 10,183,002’s glyceryl tri[4-phenylbutyrate] ammonia-based dosing algorithm?
The patent is framed as a dosing-and-monitoring method rather than composition of matter. Claim coverage is directed to: (1) UCD patient selection (no hyperammonemic crisis; fasting ammonia below ULN), and (2) a stepwise decision process that uses a single fasting plasma ammonia reading to drive an increased dose vs no increase.
What the independent claim covers (claim 1)
Claim 1 is a method comprising all of the following in sequence:
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Patient state gating
- Treating a “subject with a urea cycle disorder (UCD)” who has:
- fasting plasma ammonia level less than the upper limit of normal, and
- not experiencing a hyperammonemic crisis.
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Initial dosing
- Orally administering an initial dosage of glyceryl tri[4-phenylbutyrate] (GT4PB).
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Single measurement after steady state
- After a time sufficient for GT4PB to reach steady state, the method requires:
- measuring a single fasting plasma ammonia level.
- explicitly not serial blood draws.
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Lab-relative thresholding
- Comparing the measured fasting ammonia to a lab-specific ULN, where ULN is relative to the reference range at the laboratory that performed the assay.
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Dose adjustment rule (direction and threshold)
- Adjusting the dosage upward only when:
- fasting ammonia is greater than half the ULN.
- The adjusted dose is greater than the initial dosage in that condition.
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Explicit likelihood statement
- The claim includes a specificity element: a subject with fasting ammonia in the range 0 to 0.5 ULN has a >80% likelihood of having an average daily ammonia level within a normal range.
This means the claim is not merely “monitor ammonia and dose PB-GT.” It is “monitor once, at a steady-state time, using a single fasting ammonia relative to lab ULN, and increase dose only if above 0.5 ULN,” with the probability statement embedded in the method scope.
Dependent claim narrowing
- Claim 2: steady-state time 48 hours.
- Claim 3: steady-state time 48 to 72 hours.
- Claim 4: steady-state time 72 hours to 1 week.
- Claim 5: steady-state time 1 week to 2 weeks.
- Claim 6: steady-state time greater than 2 weeks.
- Claim 7: repeating steps (b) to (d) until fasting ammonia is at or below half ULN.
- Claim 8: ULN is 35 µmol/L.
- Claim 9: fasting period for obtaining fasting ammonia is overnight.
Practical claim boundary points (where infringement hinges)
Coverage turns on “all-elements” satisfaction. The most likely failure points for a would-be practice to fall outside the claim are:
- No hyperammonemic crisis requirement: If the method is used during a crisis or for an actively hyperammonemic patient, claim 1’s patient gating may not be met.
- Fasting ammonia must be below ULN at the start (claim 1): a patient with baseline fasting ammonia equal to/above ULN does not fit the method’s described patient population.
- Single fasting measurement, not serial draws: methods using multiple ammonia checks at the steady-state time may avoid literal coverage.
- Dose adjustment threshold must be “> 0.5 ULN”: a method that increases dose when ammonia is ≥ 0.5 ULN (instead of strictly greater) could be an edge-case design-around depending on claim construction and the literal reading of “greater than.”
- ULN must be lab-relative: methods hardcoding a single universal ULN without tying to lab reference ranges risk non-literal exclusion.
- Probability statement: although probability may be treated as a property or intended result, it is still part of the claim language, and it strengthens the evidentiary rationale for the specific thresholding approach.
How broad is US 10,183,002’s claim scope across dosing schedules, time-to-steady-state, and lab ULN definitions?
Claim 1 is broad on GT4PB use but narrow on the monitoring and adjustment logic.
Breadth factors
Broadest elements in claim 1
- GT4PB is the only active specified.
- Treatment is for UCD.
- The “adjusted dosage is greater than initial dosage” is a simple directionality.
- The ULN is defined relative to each laboratory reference range, meaning the claim contemplates inter-lab variability.
Narrowest elements in claim 1
- “single fasting plasma ammonia level” and “not serial blood draws.”
- the threshold structure:
- initial dosing then adjustment based on whether fasting ammonia is greater than half ULN.
- the initial inclusion criterion that fasting ammonia is less than ULN (not just “measured”).
- inclusion of the probability likelihood statement tied to 0–0.5 ULN.
Time-to-steady-state narrowing via dependent claims
The dependent claim set turns time into a structured claim pathway:
- 48 hours (claim 2)
- 48–72 hours (claim 3)
- 72 hours–1 week (claim 4)
- 1 week–2 weeks (claim 5)
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2 weeks (claim 6)
This creates multiple claim “lanes” for different steady-state assumptions or clinical protocols. A method that uses, for example, 3 weeks before drawing the single fasting ammonia reading could map to claim 6; 72 hours to 1 week maps to claim 4.
“Repeating steps (b) to (d)” scope (claim 7)
Claim 7 extends the method into an iterative algorithm:
- Steps (b) to (d) are repeated until fasting ammonia is at or below half ULN.
This can matter for designs that otherwise attempt to stop after one adjustment cycle.
Specific lab threshold and fasting collection (claims 8 and 9)
- Claim 8 locks ULN to 35 µmol/L, which is a concrete parameter.
- Claim 9 locks fasting collection to an overnight fasting period, which can be important for labs or protocols using different fasting durations.
What subject-matter is likely unsupported by the claims: formulation, composition, or manufacturing patents?
Based on the claim language provided, US 10,183,002 is a method claim centered on patient management decisions. The scope does not, on its face, claim:
- GT4PB formulations (tablet, capsule, film coating) by composition, excipients, particle size, or manufacturing process.
- method steps related to conversion, metabolite monitoring, or alternative biomarkers besides fasting plasma ammonia.
- non-oral administration routes.
So, the relevant patent landscape around this number is expected to be dominated by:
- additional PB-GT dosing/monitoring patents,
- UCD treatment method patents using ammonia targets,
- and possibly regimen optimization patents tying monitoring frequency and sampling strategy.
When does US 10,183,002 expire, and how does term interact with PB-GT lifecycle and U.S. exclusivity?
No filing date, priority date, or term-calculation inputs were provided with the patent number. Without those, an accurate expiration timeline cannot be produced.
What Paragraph IV generic entry risks exist if a challenger attempts to use a different ammonia sampling schedule?
Claim 1’s “single fasting plasma ammonia level” and “not serial blood draws” structure is the most direct enforcement lever against generic substitution protocols.
Likely risk-reducing design choices for a generic challenger
A challenger seeking to avoid literal infringement could attempt to implement one or more of the following:
- use serial blood draws at the steady-state time, changing the monitoring modality from single-point measurement.
- use non-fasting ammonia measurements or mixed sampling strategies.
- apply dose adjustment rules that change the threshold logic:
- adjust only when fasting ammonia is ≥ ULN, or
- adjust on a different fraction (e.g., 0.3 ULN) rather than 0.5 ULN.
- avoid the initial patient inclusion criterion (e.g., target a broader patient population including fasting ammonia at/above ULN).
Claim coverage that still might be asserted
Even if a protocol changes sampling frequency, a plaintiff could pursue:
- doctrine-of-equivalents arguments depending on how courts construe “single” vs “not serial,” and
- additional dependent claims that may exist beyond the text you supplied (not assessed here).
What biosimilar or biologic risk maps to US 10,183,002?
US 10,183,002 is about GT4PB, a small molecule. It does not implicate biosimilars. Risk is instead generic/oral small-molecule substitution and label-driven protocol adoption.
What other patents likely co-exist with US 10,183,002 in the PB-GT and UCD dosing space?
Given the specificity of the algorithm (fasting ammonia, ULN-relative threshold, steady-state time, and “single draw”), the surrounding estate for PB-GT in UCD typically includes adjacent method-of-treatment patents that may vary along four dimensions:
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Monitoring strategy
- frequency (single vs serial)
- timing (steady-state window)
- sampling condition (fasting duration; overnight vs longer)
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Target definition
- ULN-relative targets vs fixed µmol/L targets
- thresholds at 0.5 ULN vs other fractions
- end condition (<=0.5 ULN vs <=ULN vs “normal range” defined by different criteria)
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Patient selection
- exclusion of crises
- baseline gating (fasting < ULN)
- subgroup criteria (age, baseline genotype, prior therapy) if claimed elsewhere
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Dose titration logic
- whether adjustment is always upward, whether stepwise increments are constrained, and whether downward adjustment is part of the method
The dependent claims you supplied confirm two of those dimensions are central: steady-state timing windows and ULN scaling.
How do claims 2–6 (time windows) change enforceability and licensing value?
The time-to-steady-state windows create multiple claim embodiments. For enforcement and licensing, this can be valuable because it accommodates:
- different steady-state assumptions used in clinical practice,
- different patient metabolism or adherence patterns reflected in time-to-steady-state operational definitions.
If a competing label or protocol chooses any of the stated windows, it can align with at least one dependent claim even if it deviates from the exact 48-hour embodiment.
What does claim 7 imply about ongoing monitoring and stepwise retreatment cycles?
Claim 7 makes the method iterative: repeat steps (b) to (d) until fasting ammonia is at or below half ULN. That can matter in litigation because:
- a one-time measurement-and-adjust approach may satisfy claim 1 but not claim 7,
- while a protocol with multiple follow-up single-ami measurements fits claim 7’s iterative structure.
What patent strength signals are embedded in the claim wording for enforcement?
- The claim specifies multiple concrete operational steps (oral GT4PB, single fasting measurement, lab-relative ULN, and a numeric fractional threshold).
- The claim includes dependent embodiments that map to common clinical time windows (48 hours to >2 weeks).
- The claim includes explicit practical trial-like parameters (overnight fasting; ULN set to 35 µmol/L).
This level of operational specificity tends to strengthen enforceability because it reduces ambiguity about what must be performed.
Key Takeaways
- US 10,183,002 is a GT4PB dosing and monitoring method patent for UCD patients built around a single fasting plasma ammonia measurement after a steady-state time window.
- Claim 1 hinges on all-elements compliance: patient not in crisis, fasting ammonia below ULN, oral initial GT4PB, single fasting ammonia draw (not serial), lab-relative ULN comparison, and dose increase only when fasting ammonia is greater than half ULN, with an embedded >80% likelihood statement for the 0–0.5 ULN subgroup.
- Dependent claims lock down steady-state timing windows (48 hours through >2 weeks), an iterative repeat/titrate protocol (claim 7), a fixed ULN (35 µmol/L, claim 8), and an overnight fasting condition (claim 9).
- For generic or protocol design-around strategies, the largest infringement levers are the “single” vs “serial” measurement requirement and the specific “>0.5 ULN” dose adjustment threshold.
FAQs
1) Does US 10,183,002 cover dose reduction when fasting ammonia is low?
The provided claim language covers dose adjustment where the adjusted dosage is greater than the initial dosage when fasting ammonia is >0.5 ULN. It does not claim a downward adjustment rule in the text provided.
2) Can a protocol that uses multiple fasting ammonia draws avoid infringement?
Claim 1 explicitly states “measuring a single fasting plasma ammonia level… and not serial blood draws.” A multiple-draw protocol is a potential non-literal avoidance point.
3) Is the ULN threshold fixed or lab-specific in claim 1?
In claim 1, ULN is lab-relative to the reference range at the laboratory where ammonia is measured. Claim 8 adds a fixed ULN of 35 µmol/L as a dependent narrowing.
4) What steady-state time windows are explicitly claimed?
The dependent claims cover 48 hours; 48–72 hours; 72 hours–1 week; 1 week–2 weeks; and >2 weeks.
5) Does claim 7 require repeat measurement cycles until achieving <=0.5 ULN?
Yes. Claim 7 repeats steps (b) to (d) until the fasting plasma ammonia level is at or below half ULN.
References (APA)
No external sources were provided in the prompt, and no additional bibliographic details (publication date, priority, or prosecution history) were supplied.
