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Patent landscape, scope, and claims: |
Scope and claims of U.S. Patent 9,062,014 (crystalline (R)-5-[3-chloro-4-(2,3-dihydroxy-propoxy)-benz[Z]ylidene]-2-([Z]-propylimino)-3-o-tolyl-thiazolidin-4-one) and how the patent estate blocks generic and biosimilar entry
U.S. Patent 9,062,014 claims two tightly defined crystalline solid forms of a specific (R)-configured thiazolidinone compound, distinguished by X-ray powder diffraction (XRPD) peak positions, optionally bounded water content (0 to 0.5 equivalents per equivalent API), and melting point ranges measured by DSC. The patent also claims downstream uses including transplant rejection, graft-versus-host disease (GVHD) after stem cell transplantation, and multiple autoimmune/dermatologic indications (with the same API crystalline form). Separately, the patent estate is structurally typical of “crystal form” filings: a small core claim set focused on XRPD peak patterns plus dependent claims that add thermal and hydration constraints, then broad method-of-use and composition claims that can complicate generic design-around if the claimed crystalline form (or an indistinguishable one) is used.
Because the claim text you provided is complete but the underlying bibliographic record, prosecution history, and related-family documents are not provided, the analysis below is limited to claim scope mechanics and a landscape model driven by what is inherently disclosed in the claim set you supplied. No additional patent numbers, assignees, or listed references can be asserted without the actual patent record.
What does U.S. Patent 9,062,014 claim: XRPD-defined crystalline forms of the (R)-thiazolidinone API?
Short answer: The patent claims crystal forms defined by XRPD peak positions at specified 2θ angles using Cu Kα1 radiation, with a tolerance of ±0.2°. The core distinction is two separate peak-pattern families (claims 1–10 vs claims 11–20), plus dependent refinements for water content and melting points.
Claim 1 core: XRPD peak set with hydration window (0 to 0.5 equiv H₂O)
- API identity (constant across claims):
(R)-5-[3-chloro-4-(2,3-dihydroxy-propoxy)-benz[Z]ylidene]-2-([Z]-propylimino)-3-o-tolyl-thiazolidin-4-one
- Crystalline form characterization: XRPD peaks at 2θ = 7.0°, 11.2°, 12.6°
- Measurement conditions: Cu Kα1 (λ = 1.5406 Å)
- Accuracy/tolerance: ±0.2° on 2θ
- Hydration constraint: 0 to 0.5 equivalents of H₂O per equivalent API
This creates an explicit boundary between “essentially dry” through “semi-hydrated” variants within the same claimed crystal form family.
Claim 2 adds a broader XRPD fingerprint (same hydration window as claim 1)
- XRPD peaks at 7.0°, 11.2°, 12.6° plus additional peaks:
16.6°, 18.8°, 21.3°, 23.6°, 26.0°
- No water equivalence is separately specified in claim 2; it is incorporated by dependence from claim 1.
Claims 3, 6, 7: a thermal signature (melting point ~113°C)
- Melting point about 113°C by DSC.
Claims 4, 5, 8, 9: explicit “0.5 equivalents H₂O” end-state
- Claims that from the claim 1/2 crystal form family, the product is the 0.5 equiv H₂O hydrate level.
- Claim 9 is a pharmaceutical composition claim that covers the claimed crystalline form in combination with a pharmaceutically acceptable carrier.
Claim 10: method-of-use for immunosuppression indications
- Covered indications (as written):
- rejection of transplanted organs: kidney, liver, heart, lung
- GVHD from stem cell transplantation
- autoimmune syndromes: rheumatoid arthritis, multiple sclerosis, psoriasis, psoriatic arthritis, Crohn’s disease, Hashimoto’s thyroiditis
- atopic dermatitis
- Key linking limitation: method requires administering an effective amount of the crystalline form of claim 1.
What second crystalline form does U.S. Patent 9,062,014 cover (claims 11–20): different XRPD peak set and different melting point?
Short answer: The patent also claims a separate anhydrous/semi-hydrated crystalline form family defined by a different XRPD peak constellation and a higher DSC melting point (~133°C).
Claim 11 core: alternate XRPD peaks with the same hydration window (0 to 0.5 equiv H₂O)
- XRPD peaks at 2θ = 10.5°, 22.2°, 23.4°
- Cu Kα1 radiation, λ = 1.5406 Å
- ±0.2° tolerance
- Hydration window: 0 to 0.5 equivalents H₂O per equivalent API.
Claim 12 adds an expanded XRPD list (broader fingerprint)
- Includes 10.5°, 11.1°, 11.4°, 13.6°, 13.9°, 16.3°, 20.8°, 22.2°, 23.4°, 24.1°, 25.7°, 27.7°, 27.9°, 28.7°, 29.3°
- Same measurement conditions.
Claims 13, 16, 17: melting point about 133°C
- DSC melting point ~133°C ties the crystal form to a different physical solid state than the ~113°C form.
Claims 14–18: explicit anhydrous limitation for the claim 11/12 family
- Claim 14: the API is in anhydrous form (dependent from claim 11).
- Claims 15 and 16–18 similarly tie anhydrous and melting point ~133°C to the claim 12 and its dependents.
Claims 19–20: composition and method-of-use for the claim 11 crystalline form
- Claim 19: pharmaceutical composition with the claim 11 crystal form + carrier.
- Claim 20: method for transplant rejection/GVHD/autoimmune + atopic dermatitis, administered as an effective amount of the claim 11 crystalline form.
How broad are the XRPD-based crystal claims in practice: are they “design-around-proof” or test-driven?
Short answer: These claims are broad in legal coverage because they do not require a specific synthesis route or particle morphology. They are narrow in technical scope because they hinge on a defined XRPD peak pattern at precise angles with a ±0.2° tolerance and require a bounded hydration state and/or anhydrous condition depending on the claim.
Key scope levers created by the claim language
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Peak position constraints with tolerance (±0.2°).
- This is the core infringement test for the crystalline form claims.
- A generic form-maker can attempt to avoid by producing a solid where at least one required peak shifts outside tolerance, disappears, or an added peaks pattern fails the dependent claim list.
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Use of Cu Kα1 radiation specification.
- XRPD peak positions depend on instrument setup, calibration, and radiation profile.
- The claim’s specification of Cu Kα1 and wavelength reduces variability but does not eliminate it in expert analysis. It gives a technical basis to argue whether an accused sample matches under the claim’s conditions.
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Hydration bound (0 to 0.5 equiv) in claims 1 and 11.
- This covers a range including partially hydrated states rather than only a single stoichiometry.
- That said, it also means a product engineered to be consistently outside that hydration range could try to avoid. Dependent claims (claims 4/5/8/11-family) then capture the specific 0.5 equiv endpoint.
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Anhydrous limitation (claims 14/15 and dependents).
- For the higher-melting crystal family, the patent explicitly covers anhydrous material tied to ~133°C by DSC, increasing the probability that a “fully dry” form still lands inside claim scope.
What each claim set likely covers structurally
- Lower-melting family (~113°C): claims 1–10
- XRPD peaks at 7.0/11.2/12.6 (plus additional for claim 2).
- Hydration window 0 to 0.5 equiv; also 0.5 equiv variants.
- DSC ~113°C for dependent claims.
- Higher-melting family (~133°C): claims 11–20
- XRPD peaks at 10.5/22.2/23.4 (plus expanded fingerprint in claim 12).
- Hydration window 0 to 0.5 equiv; includes anhydrous variants.
- DSC ~133°C.
Does U.S. Patent 9,062,014 cover methods of treatment broadly or only with the crystalline form limitation?
Short answer: The method claims are broad as to therapeutic target (transplant rejection, GVHD, autoimmune and atopic dermatitis), but they are legally narrow because they require administration of “an effective amount of the crystalline form according to claim 1” (or claim 11).
Method-of-use claim structure
- Claim 10 uses the claim 1 crystal form.
- Claim 20 uses the claim 11 crystal form.
- Both incorporate the API crystal limitations by reference, making method infringement tied to the solid state of the administered drug substance in the accused product.
Implication for generic solid-state variants
A generic could attempt to avoid infringement by:
- selling an alternative polymorph/solvate/non-stoichiometric form; or
- formulating in a way that converts in vivo/ex vivo to a non-matching XRPD pattern at relevant testing conditions; or
- ensuring the API solid state used in manufacture does not meet the XRPD peak requirements.
Conversely, if the generic’s API converts to a claimed XRPD pattern under manufacturing/storage/reconstitution conditions, method-of-use infringement risk increases because the claim does not require that the sponsor demonstrate stability for a long time; it requires that the administered effective amount is of the claimed crystalline form.
What formulations are protected: compositions and carriers vs functional excipient coverage
Short answer: The patent includes composition claims for pharmaceutical formulations, but they appear to be “open” with respect to the carrier because they require only “a pharmaceutically acceptable carrier.”
- Claim 9: composition containing the claim 1 crystalline form + pharmaceutically acceptable carrier
- Claim 19: composition containing the claim 11 crystalline form + pharmaceutically acceptable carrier
Practical coverage
- Excipient choices, dosage form, and route are not limited in the provided claim text.
- That means the key variable is the crystalline form identity of the API, not the formulation vehicle.
How many crystalline forms are claimed, and what is the risk split between the two peak families?
Short answer: Two crystalline form families are claimed, each with dependent breadth escalations.
Claim-count map
| Claim set |
Core claim(s) |
XRPD anchors (2θ, Cu Kα1, ±0.2°) |
DSC melting point |
Hydration limitation in core |
Extra restrictions in dependents |
| Set A |
1–10 |
7.0°, 11.2°, 12.6° (plus expansion in claim 2) |
~113°C (claims 3/6/7) |
0 to 0.5 equiv H₂O (claim 1) |
0.5 equiv specific (claims 4/5/8); composition (claim 9); method (claim 10) |
| Set B |
11–20 |
10.5°, 22.2°, 23.4° (plus expansion in claim 12) |
~133°C (claims 13/16/17) |
0 to 0.5 equiv H₂O (claim 11) |
anhydrous specific (claims 14/15/17/18); composition (claim 19); method (claim 20) |
Risk split for challengers
- If a generic enters with a solid state matching the XRPD peak families within ±0.2°, crystalline-form and composition claims are directly implicated.
- If it uses the opposite melting-point family, it can still risk method-of-use infringement if the formulation/API matches either crystal form used in the accused product.
What patent landscape does this create around a generic challenge: Paragraph IV strategy and evidentiary battles (XRPD and DSC)?
Short answer: For crystal-form patents, challenges often pivot to (i) non-infringement on XRPD peak positions and (ii) invalidity on novelty/obviousness over prior solid-state disclosures. The claim set you provided is structured to create a clean, measurable infringement test: XRPD peak angles and DSC melting point.
Where invalidity arguments typically concentrate (based on claim type)
- Prior publications, patents, or examples disclosing:
- the same compound in crystalline form with matching XRPD peaks; or
- isostructural crystals that differ only slightly yet would have been obvious to attempt; or
- dehydration/hydration interconversions that land within the same 0 to 0.5 equiv window.
- For dependent claims:
- melting point overlap could be argued if prior art shows broad DSC variability or overlapping thermal events.
Where non-infringement disputes concentrate
- XRPD testing conditions: identical radiation (Cu Kα1), calibration, sample preparation, preferred orientation effects, and peak deconvolution.
- Peak presence vs peak position: claim 1 requires peaks at specific angles; a challenger's showing may target missing peaks rather than small shifts.
- Hydration measurement: determining “0.5 equivalents” or “anhydrous” is not a typical XRPD question alone; it may use Karl Fischer, TGA, or NMR depending on expert practice.
How strong is the patent estate for this specific compound: what these claim features imply for enforceability
Short answer: Enforceability is likely strongest where the accused product uses the exact crystal solid state. These claims are engineered around objective analytical criteria (XRPD and DSC), which tends to reduce ambiguity about what “the invention” is. The method-of-use claims broaden commercial reach but still require the specific crystalline form as the administered API.
Strong points built into the claim drafting
- Objective characterization (XRPD peak lists; specified radiation; defined tolerance).
- Multiple layers (core peaks, expanded fingerprint dependent peaks, DSC constraints, and hydration/anhydrous conditions).
- Downstream hooks (composition and therapeutic method claims), increasing settlement leverage.
Potential vulnerability points for a defendant
- If prior art shows:
- the same peaks within tolerance; or
- a crystal form that can readily hydrate/dehydrate into the claimed hydration states;
then novelty and non-obviousness can weaken. The claim set itself does not control how easily the claimed material can transform from related forms.
What does the claim set imply about commercial exposure: indications are broad but the drug is single-API and crystal-state defined
Short answer: Commercial exposure is driven by whether the marketed drug substance corresponds to claim 1 or claim 11 crystalline forms. If yes, the patent can reach both “API supply” and “finished dose” and can also threaten method claims across a wide immunology segment.
Indication breadth
- Transplant rejection: kidney, liver, heart, lung
- GVHD: stem cell transplantation
- Autoimmune syndromes: rheumatoid arthritis, multiple sclerosis, psoriasis, psoriatic arthritis, Crohn’s disease, Hashimoto’s thyroiditis
- Dermatology: atopic dermatitis
Even if the commercial label covers only a subset, the method claims are not limited by dose form or patient subgroup beyond “subject in need.”
Key Takeaways
- U.S. Patent 9,062,014 claims two XRPD-defined crystalline form families of a specific (R)-configured thiazolidinone API:
- Lower-melting form (~113°C) anchored by XRPD peaks at 7.0°, 11.2°, 12.6° with 0 to 0.5 equiv H₂O (and 0.5 equiv dependents).
- Higher-melting form (~133°C) anchored by XRPD peaks at 10.5°, 22.2°, 23.4° with 0 to 0.5 equiv H₂O, including anhydrous dependents.
- The infringement framework is analytical and testable: XRPD peak positions using Cu Kα1 with ±0.2° tolerance, plus DSC melting point and hydration/anhydrous status depending on the claim.
- Composition claims (“API crystalline form + pharmaceutically acceptable carrier”) keep formulation latitude wide, making the crystal state the dominant design-around variable.
- Method-of-use claims cover a wide immunology and transplant rejection set, but infringement still requires administration of the specific claimed crystalline form (claim 1 or claim 11 crystalline form).
FAQs
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How do the ±0.2° XRPD tolerances in claims 1 and 11 affect non-infringement arguments?
They create a bounded infringement window for peak positioning; challengers target calibration, peak shifts, and whether required peaks are present within tolerance.
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Do the method-of-use claims require the finished dosage form to be crystalline, or only the API solid state?
The claims require administration of an effective amount of the claimed crystalline form, so practical disputes focus on the crystalline state of the API delivered in the accused product.
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Can a generic avoid infringement by using the other crystalline form family (113°C vs 133°C)?
Avoidance depends on whether the accused product matches neither XRPD family within tolerance and does not satisfy dependents tied to hydration/anhydrous constraints.
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What do dependent claims adding melting point (~113°C or ~133°C) add legally?
They narrow the crystalline form definition further, allowing claim differentiation in litigation: a product could match XRPD anchor peaks but dispute melting point and hydration-dependent features.
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What is the highest-risk area for challengers: crystalline-form claims or method-of-use claims?
Both carry risk, but crystalline-form and composition claims are often the primary focus because they turn on objective solid-state identity; method-of-use adds a broad therapeutic reach once the crystal state matches.
References
- U.S. Patent 9,062,014, claims 1–20 (provided claim text).
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