US Patent 10,251,896: Scope, Claim Strength, and US Landscape for Bile Acid + Phenylbutyric Acid Combination Methods
US Drug Patent 10,251,896 claims a combination-treatment method that pairs a bile acid (selected from a defined list) with a phenylbutyric acid (PBA)-class agent (selected from a defined list) for treating neurodegenerative diseases in mammals, including humans, at broadly defined dose ranges. The claims are drafted as method-of-treatment claims with mechanism-linked limitations (oxidative stress, mitochondrial dysfunction, redox homeostasis, and reactive oxygen metabolite-mediated oxidative damage, including H2O2), plus optional administration regimen and timing limitations (separate vs concurrent dosing; once/twice/three times daily).
What is the claim scope of US 10,251,896?
Core independent claim (Claim 1)
Claim type: Method of treating a neurodegenerative disease.
What is administered (two-ingredient combination):
-
Bile acid selected from:
- Tauroursodeoxycholic acid (TUDCA)
- Ursodeoxycholic acid (UDCA)
- Chenodeoxycholic acid
- Cholic acid
- Hyodeoxycholic acid
- Lithocholic acid
- Glycoursodeoxycholic acid
- plus pharmaceutically acceptable salts of the above
-
Phenylbutyric acid (PBA) selected from:
- 4-phenylbutyric acid (4-PBA)
- glycerly(Tri-4-PBA) (tri-4-PBA glycerlyate form)
- 2-(4-methoxyphenoxy) acetic acid (2-POAA-OMe)
- 2-(4-nitrophenoxy) acetic acid (2-POAA-NO2)
- 2-(2-naphathyloxy) acetic acid (2-NOAA)
- plus pharmaceutically acceptable salts of the above
Dose ranges in Claim 1 (broad):
- Bile acid: about 10 mg/kg to 50 mg/kg body weight
- PBA: about 10 mg/kg to 400 mg/kg body weight
Disease coverage: “neurodegenerative disease” (fully enumerated in dependent claim 4).
Administration requirement: “amount sufficient to treat” the disease (functional language).
Timing requirement is not mandatory in Claim 1 (timing is handled in dependent claims 13-15).
Which diseases are explicitly included (Claim 4)?
Claim 4 limits “neurodegenerative disease” to a defined list:
- Multiple Sclerosis (MS)
- Alzheimer’s Disease (AD)
- Huntington’s disease (HD)
- Parkinson’s disease (PD)
- Amyotrohic Lateral Sclerosis (ALS) (spelled “Amyotrohic” in provided text)
- Pick’s Disease
- Multi-Infarct Dementia
- Creutzfeldt-Jakob’s Disease
- Dementia with Lewy Bodies (DLB)
- Mixed dementia
- Frontotemporal dementia
Landscape implication: this list reaches beyond classic Alzheimer and Parkinson into MS, dementia subtypes, prion disease (CJD), and Huntington/ALS, increasing the number of plausible competing therapeutic approaches in a freedom-to-operate analysis for combination interventions using bile acids and PBA-class agents.
How much mechanistic narrowing exists (Claims 5-9)?
Claims 5-9 introduce mechanism-driven limitations. These can reduce literal coverage for therapies that treat “by” other pathways.
Claim 5 (cause):
- neurodegenerative disease is caused by oxidative stress or mitochondrial dysfunction.
Claim 6 (outcome mechanism for oxidative damage):
- administration reduces reactive oxygen metabolite-mediated oxidative damage in a cell.
Claim 7 (explicit ROS mediator example):
- oxidative damage is hydrogen peroxide (H2O2) mediated.
Claim 8 (redox):
- administration promotes redox homeostasis in a cell.
Claim 9 (mitochondria):
- administration reduces mitochondrial dysfunction in a cell.
Interpretation for claim strength (business lens):
- Claims 1-4 are broad (disease + two-component dose + sufficient amount).
- Claims 5-9 provide fallback positions during enforcement or validity defense by tying efficacy to concrete biological mechanisms and specific oxidative mediators.
Litigation leverage point: during infringement disputes, the patentee can pursue dependent claims that align with the defendant’s MoA narrative and patient biology (ROS/redox/mitochondria), while challengers must argue lack of support or non-correspondence for those mechanism outcomes.
Where are dose ranges further defined (Claims 10-12)?
Dependent claims provide additional “equivalent to” dose boundaries for specific bile acid and for 4-PBA.
Claim 10
- bile acid administered at about 10 mg/kg to 30 mg/kg TUDCA.
Claim 11
- PBA administered at about 10 mg/kg to 100 mg/kg of 4-PBA.
Claim 12
- PBA administered at about 30 mg/kg to 100 mg/kg of 4-PBA.
Scope effect:
- These narrow sub-ranges support targeting in enforcement and provide structured claim fallback if the broad ranges face validity attacks.
Practical consequence for R&D and product design:
- Any clinical program using TUDCA and 4-PBA doses falling into these sub-ranges is positioned to fall more clearly within the dependent claim set.
What are the administration regimen and timing coverages (Claims 13-15)?
Claim 13
- bile acid and PBA administered separately.
Claim 14
- bile acid and PBA administered concurrently.
Claim 15
- administered once a day, twice a day, or three times a day.
Scope effect:
- Claim 1 does not restrict timing; dependent claims 13-15 expand coverage to common clinical dosing schedules and combinations. A product that uses separate formulations does not avoid coverage if the dosing cadence fits.
How broad is the claim coverage overall?
Breadth drivers
- Large bile acid list (7 entities + salts)
- Large PBA list (5 entities + salts)
- Broad independent dose ranges (bile acid 10-50 mg/kg; PBA 10-400 mg/kg)
- Broad disease class with an enumerated list of major neurodegenerative indications
- No required route, formulation, or patient subgroup constraints in Claim 1 based on the provided claim set
Primary narrowing controls
- Mechanism claims require oxidative stress/mitochondrial dysfunction or specific cellular effects (redox homeostasis; oxidative damage mediated by ROS including H2O2; mitochondrial dysfunction).
- TUDCA/4-PBA specific dependent dosing ranges narrow the practical embodiment.
What is the likely enforceable “core” in US 10,251,896?
The enforceable center of gravity is:
- Combination of a selected bile acid (especially TUDCA and UDCA, given familiarity in neuro and hepatic/mito contexts)
- with a selected PBA-class compound (especially 4-PBA, and to a lesser extent tri-4-PBA glycerlyate and phenoxyacetic derivatives)
- for neurodegenerative diseases including AD/PD/MS/ALS and dementia subtypes
- at dose levels in Claim 1, with narrower dose fallbacks for TUDCA and 4-PBA
What does the claim set imply for the US patent landscape (freedom-to-operate and overlap)?
Without a full cited document list from the patent itself and without the prosecution history, landscape mapping has to be limited to the claim-level risk profile. Even so, the patent is structurally aimed at capturing a common convergence point:
- Bile acid biology (especially TUDCA/UDCA) is widely used in research for mitochondrial function and ER stress-related pathways.
- PBA derivatives (4-PBA and related phenylbutyrate chemistry) are widely known for chemical chaperone and redox/mitochondrial stress angles (histone deacetylation and protein folding effects can also be relevant, but the claims here focus on oxidative stress/redox/mitochondria).
Landscape risk category: “Known moieties, new combination + regimen + disease + mechanistic outcome” pattern.
High-overlap competitor archetypes likely in the same universe
- Combination or sequential administration programs using TUDCA or UDCA plus 4-PBA or related phenylbutyrate derivatives.
- Approaches claiming treatment of AD/PD/MS/ALS/dementias using either component while asserting cellular outcomes aligned with oxidative stress and mitochondrial dysfunction.
Low-overlap competitor archetypes
- Therapies that use bile acids outside the enumerated list (not captured by Claim 1’s bile acid selection).
- Therapies that use PBA-like molecules but not within the enumerated PBA derivatives/salts.
- Approaches that focus on neuroinflammation pathways without aligning efficacy to the claim’s oxidative/redox/mitochondrial mechanisms, if dependent claims 5-9 become the infringement target.
Where are likely infringement entry points?
The combination is explicitly required, so infringement is most likely when a defendant’s regimen includes both classes:
- Entry point A (literal to Claim 1): dosing regimen with a claimed bile acid and a claimed PBA-class compound in covered dose ranges.
- Entry point B (literal to dependent claims): regimen includes dosing frequency (once/twice/three times daily) and/or aligns with separate vs concurrent administration.
- Entry point C (mechanism alignment): preclinical/clinical data and labeling assertions align with oxidative stress and mitochondrial dysfunction, supporting pursuit of dependent claims 5-9.
What about design-around options implied by the claim language?
Design-around analysis is constrained to the literal claim structure:
- Ingredient substitution: avoid all bile acids and PBA derivatives in the enumerated groups (including salts).
- Dose-range avoidance: keep dosing outside the defined ranges (Claim 1 broad range; dependent subranges for TUDCA 10-30 mg/kg and 4-PBA 10-100 or 30-100 mg/kg).
- Timing/formulation structure: while route/formulation is not specified, if a competitor can credibly avoid “once/twice/three times” cadence, they may try to force a reliance on Claim 1 rather than dependent claims 13-15 (timing constraints are in dependents).
- Mechanism strategy: attempt to frame efficacy as not tied to oxidative stress/mitochondrial dysfunction/redox homeostasis in a cellular context, pushing infringement away from dependent claims 5-9.
Key takeaways
- US 10,251,896 is a method-of-treatment combination claim covering neurodegenerative diseases using enumerated bile acids with enumerated phenylbutyric acid-class agents.
- The independent claim (1) is broad on dose and selection lists, giving wide coverage for combination regimens that use any bile acid from the 7-compound list and any PBA-class agent from the 5-compound list.
- Dependent claims (4, 5-9, 10-12, 13-15) add fallback structure: specific disease list, oxidative stress/redox/mitochondrial dysfunction mechanisms (including H2O2), and more constrained dose subranges for TUDCA and 4-PBA, plus separate vs concurrent and daily dosing frequency.
- From a patent landscape perspective, the patent’s structure suggests it targets R&D that combines bile-acid chemistry (especially TUDCA/UDCA) with phenylbutyrate chemistry (especially 4-PBA) for major neurodegenerative indications in the US.
FAQs
1) Does US 10,251,896 require both drugs be given at the same time?
No. Claim 1 does not require timing. Dependent claims address separate (Claim 13) versus concurrent (Claim 14) administration.
2) Which bile acids are covered?
Covered bile acids are TUDCA, UDCA, chenodeoxycholic acid, cholic acid, hyodeoxycholic acid, lithocholic acid, and glycoursodeoxycholic acid, plus their pharmaceutically acceptable salts.
3) Which PBA derivatives are covered?
Covered PBA-class agents are 4-PBA, glycerly(tri-4-PBA), 2-(4-methoxyphenoxy) acetic acid (2-POAA-OMe), 2-(4-nitrophenoxy) acetic acid (2-POAA-NO2), and 2-(2-naphathyloxy) acetic acid (2-NOAA), plus their salts.
4) What mechanistic limitations exist beyond “treating” the disease?
Dependent claims require the disease be caused by oxidative stress or mitochondrial dysfunction, and/or that the combination reduces ROS-mediated oxidative damage (including H2O2) and promotes redox homeostasis and/or reduces mitochondrial dysfunction in cells.
5) What dosing ranges are explicitly defined?
Claim 1 defines bile acid about 10-50 mg/kg and PBA about 10-400 mg/kg. Dependent claims provide additional subranges for TUDCA (10-30 mg/kg) and 4-PBA (10-100 mg/kg or 30-100 mg/kg).
References
[1] United States Patent 10,251,896 (claims as provided in prompt).
