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Patent landscape, scope, and claims: |
Scope-and-claims analysis and U.S. patent landscape for US 6,762,180
Executive summary: US 6,762,180 claims a very broad genus of substituted heteroaromatic/methylene-linked indolinone-type compounds in Formula I, with dependent claims narrowing to specific substituent classes and a small set of enumerated exemplified molecules. The claim set is structurally “platform-genus” style: (1) an enormous variability budget across aromatic substitution, heteroatom identity, ring-size/heterocycle options, and linker substituents, (2) explicit coverage of tautomers and physiologically acceptable salts, and (3) composition claims that cover salts and formulated dosage forms without requiring a specific therapeutic use. Practically, the patent is strong as a blocking composition-of-matter right against close structural design-arounds only to the extent competitors land within Formula I’s constraint space. It is weaker against intentional carve-outs via (a) deleting/altering a key scaffold element that breaks Formula I, or (b) moving outside the allowed substituent sets (including specific R1/R2/R3/R4/R5/R6/R7/R10/R11/R12… definitions) or the permitted salt/tautomer embodiments. Below is the scope construction, claim-by-claim narrowing path, and the likely infringement surface you can use for FTO, licensing, and litigation posture.
US 6,762,180: What compounds does Formula I cover and how broad is the genus?
Fast read: Formula I architecture
Claim 1 covers “a compound of the formula I” where the substitution pattern is controlled by multiple variables:
- X = oxygen atom (fixed to O)
- R2 = a carboxy group (in Claim 1)
- R3 = H, C1-6 alkyl, C3-7 cycloalkyl, CF3, or heteroaryl; or aryl groups (phenyl/naphthyl) including mono/disubstitution with halogens/CF3/C1-3-alkyl/C1-3-alkoxy; additional allowed substituents on phenyl/naphthyl include OH, cyano, carboxy, carboxy-C1-3-alkyl, alkoxycarbonyls, amino/aminocarbonyls, nitro, and many sulfonamide-type substituents
- R4 = C3-7 cycloalkyl group, with additional allowances for substitutions on the “methylene group in position 4” for 6- or 7-membered ring systems (including replacement by heteroatoms or sulfonyl/amine motifs)
- R6 = an alkyl-substituted phenyl ring substituent family with broad substituent allowance, plus a further nested definition that covers multiple ring fusion and heterocycle alternatives
- R1 includes hydrogen OR carbonyloxycarbonyl/carboxyl-derived groups (C1-4-alkoxycarbonyl or C2-4-alkanoyl in Claim 1)
- R5 = H or C1-3 alkyl (in the claim’s tail)
- R7, R8, R9, R10, R11, R12, R13, R14, R15, R16, R17, and p/q/r integers define further substituent families on pendant linkers and secondary substituent positions
- Claim 1 explicitly includes: tautomers and salts (“or a tautomer or salt thereof.”)
What the structure constraints imply
Even with enormous combinatorics, Formula I is not “anything goes.” It is bounded by:
- A fixed macro-scaffold embodied by the “formula I” skeleton (not reproduced in your prompt, but implied by the claim language and the enumerated examples in claim 5).
- Fixed functional-role definitions for X and R2 in Claim 1.
- Specific allowable chemistry for substitutions at multiple scaffold positions, including:
- allowed ring sizes (C3-7 cycloalkyl; C4-7 cycloalkyleneimino; 5- or 6-membered heteroaryls)
- allowed heteroatom replacements (methylene replaced by O or S; also sulfinyl/sulphonyl and NH/N-alkyl alternatives)
- allowed functional group classes (carboxy, alkoxycarbonyl, aminocarbonyl, sulfonylamino, sulphonylamide variants, cyano, nitro, halogens, CF3, alkylamino substituents, and related protected/precursor carbonyl embodiments)
- explicit allowances for N-alkylation states and phthalimide inclusion
- Explicit salt coverage (“physiologically acceptable salt”).
Practical scope: the “design-around geometry”
- If a competitor stays inside the scaffold and places substituents from the allowed sets for the relevant R-groups, they fall within Claim 1’s genus.
- If they alter any scaffold element that is essential to “formula I” (not just substituents) or use substituents outside the enumerated definitions (including those tied to p/q/r and linker motifs), they can avoid Claim 1.
- The broadest “risk zone” is where competitors use amine-rich pendant substituents (piperidinyl, piperazinyl, dimethylamino/ethylamino motifs) because those are repeated in the examples and are within multiple variable definitions.
Claim 1 vs. Claim 2 vs. Claim 3 vs. Claim 4: How do the dependent claims narrow Formula I?
What patents protect (Claim 1): the broad genus
Claim 1 is the apex:
- X = O
- R2 = carboxy
- R1 = H or C1-4-alkoxycarbonyl or C2-4-alkanoyl
- Many branches for R3/R4/R6.
- Includes extensive aromatic substitution latitude, plus heteroaryl and fused-ring options, plus explicit tautomer/salt.
Claim 2: tighter R2 and R6/R4/R3 class restrictions
Claim 2 is a narrowed embodiment of Claim 1:
- R2 = carboxy
- R1 and R3 “as defined in claim 1”
- Restricts some carbonyl and aromatic substitution sets (for example R2 in Claim 2 remains carboxy; R4 is C3-7 cycloalkyl).
- Keeps the same broad scaffold flexibility around cycloalkyl and substituted phenyl via R6 and its substitution list.
- Still includes tautomers and salts.
Claim 3: major narrowing of R1/R3/R4
Claim 3 narrows more materially:
- R1 = H or specific alkoxycarbonyl/phenoxycarbonyl/carbamoyl-linked classes
- R2 = carboxy
- R3 restricted to C1-4 alkyl or phenyl (with halogen/CF3/alkoxy/alkyl substitutions)
- R4 restricted to C5-6 cycloalkyl (cyclohexyl-type) or phenyl/permitted phenyl substitution
- Specific permitted cycloalkyleneimino ring-size options are reduced (e.g., 5- or 6-membered cycloalkyleneimino in multiple places)
- Still includes broad pendant amine and sulfonamide substitutions but with narrower backbone/position definitions.
Claim 4: “specific carve-down” to a small region of substituent space
Claim 4 is narrower still:
- R1 and R5 each = hydrogen
- R2 = methoxycarbonyl, ethoxycarbonyl, or aminocarbonyl
- R3 = phenyl
- R4 = phenyl monosubstituted by R6
- R6 = N-methyl-imidazol-2-yl, or an unbranched C1-3 alkyl terminally substituted by an amino-bearing group (including piperidino motifs), or specified N(R12)-CO-(CH2)p-R13 forms, or specified N(R14)-(CH2)q-(CO)r-R15 forms
Claim 4 is where the claim set becomes most “product-like” for enforcement leverage, because it forces a particular combination of substituent classes.
Claim 5: Which enumerated compounds are expressly included?
Claim 5 explicitly lists a finite set of exemplified/selected molecules under the Markush-like umbrella (with numbering (a) through (t)).
These are all 3-Z-[1-(4-(substituted anilino)-1-phenyl-methylene)]- 6-alkoxycarbonyl or 6-carbamoyl-2-indolinone style structures, with variations in the para-anilino substituent on the aniline ring and the indolinone carbonyl at position 6. The repeated motifs across the list:
- Para aniline substituted with piperidin-1-ylmethyl,
- Para aniline substituted with dimethylaminomethyl, or
- Para aniline substituted with (2-dimethylamino-ethyl) or (3-dimethylamino-propyl) amidomethyl groups,
- Para aniline substituted with methylsulphonylamino or acetylamino analogues,
- Alternative methoxycarbonyl vs ethoxycarbonyl vs carbamoyl at the indolinone “6” position,
- One includes imidazol-2-yl,
- One includes piperazinyl via carbonylmethyl group.
Why claim 5 matters
- Claim 5 provides clean, infringement-ready targets because it is not merely variable-by-variable; it is enumerated.
- In litigation, Claim 5 reduces claim-construction battles over R-group mapping for those listed embodiments.
Claim 6-8: What additional rights do composition and salt claims add?
Claim 6: physiologically acceptable salts
Claim 6 adds:
- salt forms of claims 1-4 compounds.
This matters because even if a generic challenger argues a “freebase” form is not covered, salts often remain within literal scope if claimed broadly.
Claim 7: pharmaceutical composition
Claim 7 covers:
- pharmaceutical composition containing a compound of claims 1-4 (or physiologically acceptable salt) plus a pharmaceutically acceptable carrier.
No dosage form is specified, so this is a broad composition-of-matter/combination right for formulations.
Claim 8: one enumerated compound
Claim 8 narrows further to:
- 3-Z-[1-(4-(N-((4-methyl-piperazin-1-yl)-methylcarbonyl)-N-methyl-amino)-anilino)-1-phenyl-methylene]-6-methoxycarbonyl-2-indolinone (or salt)
This is an additional, separately enforceable anchor on a very specific piperazinyl-containing embodiment.
How many “sub-classes” are effectively covered, and where is the infringement likelihood highest?
Sub-class mapping by chemical handles
From the claim language and enumerated set, the core infringement handles fall into:
- Indolinone core with Z-geometry at 3-position (as reflected by “3-Z-” in claim 5)
- Methylene-linked anilino substituent with para-NH-aryl linkage to substituted aniline
- 6-carbonyl substituent options:
- ethoxycarbonyl,
- methoxycarbonyl,
- carbamoyl (and aminocarbonyl in claim definitions)
- Para-aniline substituent amines:
- piperidinylmethyl,
- dimethylaminomethyl,
- dimethylamino-ethyl or -propyl (including N-acetyl or N-methylsulfonyl variants),
- imidazole substitution,
- piperazinyl-carbonylmethyl variants.
Highest-likelihood infringement zone
- Competitors using piperidine/piperazine and dimethylamino alkyl chains on the para aniline, combined with 6-alkoxycarbonyl indolinones, are most likely to land within:
- Claim 1’s genus constraints, and
- directly within the enumerated embodiments of Claim 5 (or Claim 8 if the piperazinyl carbonylmethyl-methylamino pattern matches).
What would be considered “out of scope” design-arounds under these claims?
Based on the claim text alone, design-arounds can target:
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Breaking the scaffold required by “formula I”
Any change that removes the “formula I” backbone element (not just substituents) moves outside literal coverage.
-
Substituent definitions outside the allowed ranges
Examples of constraint levers include:
- ring sizes (C3-7 cycloalkyl; 4-7 membered cycloalkyleneimino; 5-6 membered heteroaryls)
- permitted heteroatoms (X fixed to oxygen in Claim 1 and dependent claim set you provided)
- permitted carbonyl precursor substitutions (tert-butoxycarbonyl precursor language)
- allowed halogen set and alkyl lengths.
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Removing salt/tautomer equivalents only if the competitor truly avoids the salt forms
Since salts are expressly claimed, “salt avoidance” is a weak design-around unless the product and manufacturing avoid forming claimed salts and avoid crystalline salt embodiments.
Litigation and Orange Book status: cannot be completed from the provided record
No information was provided about:
- the drug name linked to US 6,762,180,
- the corresponding NDA/ANDA/BLA identifier,
- Orange Book listing entries,
- reexamination/prosecution history outcomes,
- district court or ITC litigation,
- settlements or Paragraph IV outcomes.
Without those facts, a complete and accurate U.S. enforcement and regulatory landscape cannot be produced.
Key Takeaways
- US 6,762,180 Claim 1 is a broad genus over a fixed scaffold, with large combinatorial variability across R1/R2/R3/R4/R6 and multiple linker substituent families, and it explicitly covers tautomers and salts.
- Claims 2-4 narrow by substituent-class and ring-size constraints, with Claim 4 imposing specific combinations (notably R1 = H, R5 = H, and defined R2/R3/R4/R6 architectures).
- Claim 5 enumerates specific compounds (a)–(t), giving litigation-friendly targets that map directly to particular para-aniline substituent chemistries (piperidines, dimethylaminomethyl, dimethylamino-ethyl/propyl with amide/sulfonamide variants, imidazolyl, and piperazinyl-carbonylmethyl derivatives).
- Claims 6-7 broaden into salts and pharmaceutical compositions, extending enforceability to formulation-level activity.
- Claim 8 is a single additional enumerated piperazinyl embodiment, tightening coverage further around that specific structure.
FAQs
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Does US 6,762,180 cover free base only, or also salts and tautomers?
The claims explicitly include tautomers and physiologically acceptable salts (Claims 6-8 referencing salts).
-
Which claim is most useful for enforceability against near-identical competitor structures?
Claim 5 because it enumerates specific 3-Z-…-6-alkoxycarbonyl/6-carbamoyl indolinone embodiments.
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Can a competitor avoid infringement by changing the para-aniline substituent while keeping the indolinone core?
Only if the new para-aniline substituent is outside the defined R-group chemistries for the relevant claim(s), including the specific families in Claim 1/2/3/4 and the enumerated set in Claim 5.
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Do the claims cover pharmaceutical compositions with carriers?
Yes. Claim 7 covers pharmaceutical compositions containing compounds of Claims 1-4 (or salts) with pharmaceutically acceptable carriers.
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Is the scope limited by ring size or linker parameters?
Yes. Multiple nested definitions tie scope to ring sizes (C3-7, C4-7, 5-6 membered heteroaryl) and to linker lengths (integers p/q/r/m/n/o) for specific substituent classes.
References
- U.S. Patent No. 6,762,180.
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