United States RE48286: Scope, Claims, and FXR-Directed Patent Landscape
US RE48286 is a reissue covering a specific class of FXR (farnesoid X receptor) modulatory compounds and a set of downstream claim categories that lock in: (i) compound identity (including salts and solvates), (ii) two specific amino-acid conjugates (glycine and taurine) for the ethyl-substituted species, (iii) formulations, and (iv) multiple method-of-treatment indications centered on lipid disorders and cardiovascular disease. The claim set also includes radiolabeled versions (with a defined tritium embodiment).
What exactly does RE48286 claim?
RE48286’s provided claim text covers four layers of scope:
-
Core chemical genus (Formula I)
- Claim 1: “A compound of formula I… wherein R is ethyl and pharmaceutically acceptable salts, solvates or amino acid conjugates thereof.”
- Claim 12: specifies “the compound of formula (I) wherein R is ethyl.”
- Claim 13 and Claim 14 separately capture salts and solvates.
-
Two amino-acid conjugates as explicit species
- Claim 2: “The glycine conjugate of a compound of formula (I) wherein R is ethyl.”
- Claim 3: “The taurine conjugate of a compound of formula (I) wherein R is ethyl.”
-
Pharmaceutical product
- Claim 4: “A pharmaceutical formulation comprising a compound according to claim 1 and a pharmaceutically acceptable carrier or diluent.”
-
Use claims that map to FXR-mediated disease and cardiovascular endpoints
- Claim 5 (FXR-mediated disease/condition): includes
- hypercholesteremia
- hyperlipidemia
- low HDL-cholesterol
- high triglycerides
- Claim 6 (cardiovascular disease): includes
- athertherosclerosis
- atherosclerosis
- hypercholesteremia
- Claim 7 narrows further: atherosclerosis.
- Claims 8 and 9 are functional lipid endpoints:
- increasing HDL cholesterol
- lowering triglycerides
-
Radiolabeling embodiment
- Claim 10: “The compound of claim 1, wherein said compound is radiolabeled.”
- Claim 11: “wherein said compound is tritiated.”
How broad are the compound claims?
Is RE48286 a broad genus or a narrow single-substituent series?
The key narrowing is that R is fixed to ethyl across the compound and most dependent species:
- Claim 1 restricts genus to “formula I” compounds where R = ethyl.
- Claims 2, 3, 12 reaffirm the ethyl substitution specifically for glycine and taurine conjugates and for the ethyl variant.
That makes the chemical scope “genus by formula” but “species by substituent,” limiting potential design-around via varying R.
What sub-scope is captured beyond the parent compound?
RE48286 extends coverage through typical chemical form and utility branching:
- Salts: Claim 13 captures pharmaceutically acceptable salts as a distinct category.
- Solvates: Claim 14 captures solvates.
- Amino-acid conjugates:
- glycine conjugate (Claim 2)
- taurine conjugate (Claim 3)
- Radiolabeled forms:
- radiolabeled generally (Claim 10)
- tritiated specifically (Claim 11)
This structure matters for freedom-to-operate because it blocks multiple “nearby” product variants that might otherwise be argued as non-infringing.
Practical enforcement posture
From a litigation and licensing perspective, RE48286 supports several infringement theories:
- Direct infringement of the parent ethyl-substituted compound (Claim 1 / Claim 12).
- Direct infringement of salts/solvates (Claims 13-14).
- Direct infringement of glycine and taurine conjugates (Claims 2-3), even if a competitor argues a different non-conjugated route.
- Direct infringement of radiolabeled versions (Claims 10-11), which can be relevant for imaging, distribution studies, bioequivalence programs, and PK characterization.
How broad are the method-of-use claims?
What disease scope is explicitly included?
RE48286’s use claims explicitly enumerate lipid and cardiovascular targets and also frame them as FXR-mediated.
Claim 5 (FXR-mediated disease/condition) includes:
- hypercholesteremia
- hyperlipidemia
- low HDL-cholesterol
- high triglycerides
Claim 6 (cardiovascular disease) includes:
- atherosclerosis
- atherosclerosis (spelled as “artherosclerosis” in the provided text) and
- hypercholesteremia
Claim 7 narrows:
- atherosclerosis (explicit)
Claims 8-9 are functional:
- increasing HDL cholesterol
- lowering triglycerides
What does the “FXR mediated” language do?
Claim 5 creates a category constraint: the claim requires an FXR-mediated disease/condition and an FXR use rationale embedded in the claim text. In practice, this ties the method to a particular mechanistic class even when the clinical endpoint is a lipid parameter.
However, claims 6-9 broaden practical reach beyond “FXR-mediated” by grounding use in:
- cardiovascular disease (claim 6-7)
- lipid endpoints (claims 8-9)
So, a competitor cannot avoid all use coverage simply by arguing the disease label differs. The functional HDL and triglyceride endpoint claims can still be implicated if the regimen is designed for those endpoints using the claimed compound.
Claim-by-claim scope map (what is covered and what isn’t)
Below is a compact scope map derived from the provided claim set.
| Claim |
Category |
Covered subject matter |
Key limiter(s) |
| 1 |
Compound (genus) |
Formula I compound |
R = ethyl; includes salts, solvates, amino acid conjugates |
| 2 |
Species (conjugate) |
Glycine conjugate of Formula I |
R = ethyl |
| 3 |
Species (conjugate) |
Taurine conjugate of Formula I |
R = ethyl |
| 4 |
Formulation |
Formulation comprising claim 1 compound |
“pharmaceutically acceptable carrier or diluent” |
| 5 |
Method (FXR-mediated) |
Treating FXR-mediated disease/condition |
disease selected from list; compound is claim 1 |
| 6 |
Method (cardiovascular) |
Treating cardiovascular disease |
disease selected from list |
| 7 |
Method (narrow) |
Treating atherosclerosis |
claim 6 + atherosclerosis |
| 8 |
Method (endpoint) |
Increasing HDL cholesterol |
compound is claim 1 |
| 9 |
Method (endpoint) |
Lowering triglycerides |
compound is claim 1 |
| 10 |
Compound variant |
Radiolabeled claim 1 compound |
radiolabeled |
| 11 |
Compound variant (specific) |
Tritiated radiolabeled compound |
tritiated |
| 12 |
Compound (species) |
Formula I with R=ethyl |
R fixed |
| 13 |
Chemical form |
Pharmaceutically acceptable salt |
salts of claim 1 |
| 14 |
Chemical form |
Solvate |
solvates of claim 1 |
What is not stated in the provided claim set: there is no explicit restriction to dosage, route, patient population, or clinical study design. No pediatric, renal/hepatic impairment, or regimen timing limitations appear in the provided text.
Where the claim set concentrates infringement risk
Highest leverage claims
- Claim 1 / Claim 12: direct product coverage for the ethyl-substituted Formula I compounds plus salts/solvates/conjugates.
- Claims 2-3: explicit glycine and taurine conjugates are often selected for solubility, stability, and pharmacokinetic tailoring. Those are “hard” species claims that reduce argument room.
- Claims 5-9: multiple method constructs cover both mechanistic framing (FXR-mediated) and endpoints (HDL, triglycerides) that map directly to clinical development choices.
Technical and regulatory touchpoints
- A development program for lipid disorders typically claims HDL and triglyceride outcomes. Claims 8-9 align with how efficacy is drafted in clinical and label language, increasing the chance those claims are read onto competitor regimens if they use the claimed compound.
- Radiolabeled and tritiated species often appear in ADME/PK, receptor occupancy, and distribution studies. Claims 10-11 give a pathway to challenge research and non-clinical work if the tritiated materials are made or used in an infringing manner.
Design-around and vulnerability analysis (based on the provided claim text only)
Changing R away from ethyl
Because R is consistently limited to ethyl (Claim 1, Claim 2-3, Claim 12), the most direct design-around is to develop a Formula I analog where R ≠ ethyl. The provided claim set does not state alternative R values or claim them as equivalents inside the literal text.
Avoiding conjugate embodiments
If a competitor uses the parent compound without glycine or taurine conjugation, claims 2 and 3 are not triggered for those specific conjugates. But if the method claims still use “a compound according to claim 1,” use coverage remains a risk if the parent itself is within Claim 1.
Circumventing by changing the clinical endpoint wording
Claims 8-9 are endpoint-driven. If a competitor targets endpoints not included in the functional claim text, claim 8-9 may not read directly. Still, Claim 5 (FXR-mediated disease list) and Claim 6-7 (cardiovascular disease list) can capture common lipid/cardiovascular indications even when trial endpoints differ.
Avoiding radiolabeled materials
If the competitor never makes radiolabeled or tritiated versions of the claimed compound, Claims 10-11 may be avoided. But that does not remove risk from the core compound and method claims.
US patent landscape: what can be concluded from the reissue’s claim structure
Landscape logic: RE48286 sits in a mechanistic, endpoint-driven cluster
Even without mapping specific family members, the claim architecture indicates RE48286 targets a mature development area:
- Mechanism: FXR-mediated disease treatment.
- Indications: classic dyslipidemia and cardiovascular disease labels/endpoints.
- Product forms: active compound plus formulation, salts/solvates, conjugates, and radiolabeled embodiments.
This is the typical claim blueprint for compounds where:
- lead structure is chemically defined by a formula,
- formulation and prodrug/conjugate variants are commercializable,
- and method claims are drafted to cover both mechanistic and clinical endpoints.
Implication for portfolio strategy
From a freedom-to-operate and licensing perspective, RE48286 creates a layered barrier:
- Product barrier via Claim 1 and its chemical-form dependents.
- Variant barrier via conjugates and radiolabeled species.
- Use barrier via multiple ways to draft the medical indication around lipid/cardiovascular outcomes.
That combination often forces competitors to either:
- license the IP, or
- move to a different chemical scaffold where the “R=ethyl” limitation is not met, or
- focus on different mechanisms and indications not captured by the claim lists.
Key Takeaways
- RE48286 claim scope is anchored on Formula I with a hard restriction: R = ethyl across the compound and key dependent claims.
- Coverage extends beyond the parent molecule to salts, solvates, glycine and taurine conjugates, formulations, and radiolabeled (including tritiated) embodiments.
- Method-of-use coverage is broad in drafting posture, capturing FXR-mediated lipid disease (Claim 5) plus cardiovascular disease (Claim 6-7) and functional lipid endpoints (HDL increase and triglyceride lowering) in Claims 8-9.
- Enforcement leverage comes from the stacking of product claims with multiple independent method constructs rather than relying on a single indication wording.
FAQs
-
Does RE48286 cover only the ethyl-substituted compound or also salts and solvates?
Yes. Claim 1 covers the ethyl-substituted Formula I compound and explicitly includes pharmaceutically acceptable salts and solvates (and amino acid conjugates). Claims 13-14 separately claim salts and solvates.
-
Are glycine and taurine conjugates covered even if a product is not radiolabeled?
Yes. Claims 2 and 3 explicitly claim the glycine conjugate and taurine conjugate of the ethyl-substituted Formula I compound.
-
What indications are most directly covered for disease treatment?
Claim 5 covers FXR-mediated disease/conditions including hypercholesteremia, hyperlipidemia, low HDL-cholesterol, and high triglycerides. Claim 6-7 cover cardiovascular disease including atherosclerosis and hypercholesteremia.
-
Can a competitor avoid infringement by targeting different lipid endpoints?
Endpoint claims exist for HDL increase (Claim 8) and triglyceride lowering (Claim 9). Avoiding those endpoints may reduce exposure for those specific claims, but exposure can remain under Claim 5 and Claim 6-7 depending on the indication pursued.
-
Do the claims reach radiolabeled and tritiated versions?
Yes. Claim 10 covers radiolabeled compounds of Claim 1 and Claim 11 specifies tritiated embodiments.
References
- United States Patent RE48286 (reissue) claim text provided in the prompt.
