United States Patent 9,474,779 (Scope, Claim Coverage and US Patent Landscape for IDH1-Mutant Cancer Compounds)
US 9,474,779 claims broad coverage of IDH1-mutant small-molecule inhibitors framed as “compound of Formula I/II-a,” plus pharmaceutical compositions and IDH1-mutation treatment methods (including R132H/R132C; multiple cancer indications). The claim set is structurally broad on substituent latitude (R1-R5/R6/R7) and functionally broad on permitted scaffold variations (non-aromatic ring A with 0–1 extra heteroatoms; variable carbocycle/aryl/heteroaryl/alkyl substituents; multiple halogen, cyano, CF3, amine sulfonamide, alkoxy, and ester/ether motifs).
Practical outcome: the estate can capture large families of closely related analogs that preserve (i) the core “amide + substituted ring A + variable aromatic/heteroaryl/alkyl terminus” architecture and (ii) the permitted substitution pattern constraints. It also provides method-of-use exclusivity tied to IDH1 mutation–driven production of R(-)-2-hydroxyglutarate and explicit R132H/R132C embodiments.
What does US 9,474,779 claim cover (Formula I and Formula II-a compound scope)?
Short answer: US 9,474,779 protects a genus of compounds defined by Formula I (Claims 1–12) and tighter sub-genus structures under Formula II-a (Claims 4–11), plus compositions and IDH1-mutation treatment methods (Claims 13–18).
Claim 1: genus of “compound of Formula I”
Claim 1 is drafted as a Markush-style broad genus with multiple substitution variables:
- Core: compound of Formula I (or pharmaceutically acceptable salt/tautomer/isotopologue/hydrate).
- R1: optionally substituted C4–C6 carbocyclyl.
- R2 and R3: independently optionally substituted aryl or heteroaryl.
- R4: can be alkyl, aryl, heteroaryl, aralkyl, or heteroaralkyl (each optionally substituted).
- Ring A: 4–6 membered non-aromatic ring with 0–1 additional heteroatoms (N, O, S); optionally substituted with one or two R5 groups.
- R5 (ring A substituents): independently selected from a wide set including:
- halo
- CF3
- CN
- OR6
- N(R6)2
- carbonyl-adjacent/alkyl ester-like substituents: “—C(O)C1–C4 alkyl”
- haloalkyl, alkyl optionally substituted with —OR6 or —N(R6)2
- alkoxy/alkoxyamino and sulfone/sulfonamide motifs:
- —O—C1–C4 alkyl optionally substituted with halo, —OR6 or —N(R6)2
- —SO2N(R6)2
- —SO2(C1–C4 alkyl)
- —NR6SO2R6
- carbocycle/heteroaryl options:
- C3–C5 carbocyclyl optionally substituted with one or two R6 groups
- —O—(C3–C6 carbocyclyl optionally substituted…)
- 5–6 membered heteroaryl
- ester-like groups: “—C1–C4 alkyl-C(O)O—C1–C4 alkyl” or “—C(O)O—C1–C4 alkyl”
- R6: each independently H or C1–C3 alkyl.
IP interpretation: Claim 1 is designed to cover structural families that keep a specific scaffold relationship (Formula I) while permitting wide substitution at the ring A and aromatic/heteroaryl positions within the R2/R3/R4/R5/R6 windows.
Claim 2: narrower sub-genus
Claim 2 further constrains the ranges:
- R1: C4–C6 carbocyclyl optionally substituted with 1–3 R7.
- R2/R3: aryl/heteroaryl optionally substituted with 1–3 R7.
- R4: alkyl or aryl/heteroaryl/aralkyl/heteroaralkyl, each with 1–3 R7 substitution.
- R5: still from Claim 1 set, but now R6 is constrained to H or C1–C4 alkyl.
- R7: independently halo / CF3 / CN / OR6 / N(R6)2 / sulfone/sulfonamide motifs / amino-sulfones / carbocycle/heteroaryl/ester motifs.
Net effect: Claim 2 targets compounds where the aryl and carbocycle portions bear multiple halogen/small-electron-withdrawing/amine-sulfone substituents.
Claim 3: narrower still on R2 and R3
Claim 3 requires each R2 and R3 is aryl optionally substituted with 1–3 R7 (i.e., it excludes heteroaryl at R2/R3 that would otherwise be available in Claim 1/2).
What exact substituent “buckets” define ring A and its R5 options under the patent?
Short answer: Ring A is a small non-aromatic ring (4–6 members) with optional 0–1 extra heteroatom and 1–2 R5 substituents drawn from a broad electrophile/solubilizing/medicinal-chemistry toolbox.
Ring A constraints that matter for design-around
- Non-aromatic 4–6-membered ring: ring A cannot be aromatic; this excludes some heteroaromatic replacements.
- 0–1 additional heteroatoms (N/O/S): ring A is not heavily heteroatom-rich.
- R5 count: one or two R5 substituents on ring A.
- R5 chemical classes (selected examples from the claim):
- strong EWG halogens and CF3/CN
- alkoxy and dialkylamino patterns via OR6 and N(R6)2
- carbonyl and ester motifs (including “—C(O)C1–C4 alkyl” and ester formats)
- sulfone/sulfonamide motifs (SO2N(R6)2, SO2(alkyl), NR6SO2R6)
- heteroaryl and carbocycle substituents (5–6 membered heteroaryl; C3–C5 carbocycle and O-linked carbocycle)
Design constraint signal: A competitor can avoid infringement only by moving outside the Formula I/II-a framework or substituent sets, not merely by swapping one small group if it remains within permitted R5/R6/R7 definitions.
What does “Formula II-a” add (Claims 4–11) and where are R10/R11 bounded?
Short answer: Claim 4 builds a sub-genus requiring Formula II-a and specifies R10 = C R11 or N with enumerated R11 options. Claims 5–11 then clamp R1 and ring A patterns further.
Claim 4: Formula II-a with R10/R11
- R10: “CR11 or N”
- R11 options (enumerated):
- —F
- —SO2NH2
- —SO2CH3
- —S(O)CH3
- —CN
- methoxy
- —OCH2OH
- —CH2OH
- —SO2N(CH3)2
- —SO2NHCH3
- NHSO2CH3
- —CH2CH2OH
- —N(CH3)2
- t-butyl
- cyclopropyl
- —C(OH)(CH3)2
- —OCF3
- —OCHF2
- —O-cyclopropyl
- -1-methyl-cyclopropyl
- pyrazolyl
Claim 5: tighter R1
- R1 is C4 or C6 cycloalkyl optionally substituted with 1–2 R7 groups.
- Each R7 associated with R1 is halo.
Claims 6–8: ring A structure and substitution count
Claims 6–8 include ring A depictions that further restrict the ring A attachment points and ring A substitution pattern; the text provided truncates the embedded structures, so only the claim logic can be stated from your excerpt: ring A is still the variable ring A in the II-a framework, now constrained to particular depicted substitutions/attachment chemistry.
Claim 9–11: R4 restrictions
- Claim 9: R4 is aryl or heteroaryl, each optionally substituted with 1–3 R7.
- Claim 10: R4 is specifically the depicted aryl/heteroaryl with substituents, with R7 = {F, Cl, methyl, CF3, CN, OMe, N(R6)2} (per your excerpt).
- Claim 11: further constrains substituent sets on R4 positions:
- R100 = H, methyl, Cl, CF3, CN, OCH3, or N(R6)2
- R101 = H, F, or methyl
Net effect of Claims 4–11: the patent also covers specific medicinal-chemistry variants (not just generic classes), especially where R11 includes sulfonamides/sulfones, hydroxymethyl/ethanol motifs, and halogenated alkoxy groups.
How do Claims 12–18 expand protection beyond the compound (composition and method-of-use)?
Claim 12: “any one of the compounds from Table 1”
This is an additional protection layer: if Table 1 enumerates specific exemplified compounds, Claim 12 locks those individual embodiments into a standalone claim. This is usually important for enforcement because it narrows proof requirements: you can assert either (i) infringement of the genus or (ii) infringement of a named table compound.
Claim 13: pharmaceutical composition
- Composition includes:
- a compound of Claims 1–12
- a pharmaceutically acceptable carrier
Claim 14: combination therapy
- Adds “a second therapeutic agent useful or treating a cancer” to the composition.
Claim 15: method of treating cancer with IDH1 mutation
The method claim requires:
- cancer characterized by an IDH1 mutation
- the IDH1 mutation produces the new ability to catalyze:
- NAPH-dependent reduction of α-ketoglutarate to R(-)-2-hydroxyglutarate
- administration of the composition of Claim 13.
Claim 16: explicit IDH1 mutations
- IDH1 mutation is:
- IDH1 R132H or IDH1 R132C.
Claim 17: explicit cancer list
Cancer is selected from:
- glioma (glioblastoma)
- acute myelogenous leukemia (AML)
- melanoma
- non-small cell lung cancer (NSCLC)
- cholangiocarcinomas
- chondrosarcoma
- myelodysplastic syndromes (MDS)
- myeloproliferative neoplasm (MPN)
- colon cancer
Claim 18: combination therapy method
Adds a second anti-cancer agent in the method.
Enforcement signal: the method-of-use claims are not limited to a single tumor type. If an accused product is used for any of the enumerated cancers with an R132H/R132C IDH1-mutant diagnosis, method coverage is easier to frame.
How strong is the patent estate around US 9,474,779 given this claim breadth?
Strength factors from claim drafting
- Genus coverage: Claim 1 is broad across multiple substitution variables (R1-R4 and R5/R6). That increases the chance that competitor analogs fall within the literal scope.
- Sub-genus and exemplified coverage: Claims 4–11 add narrower enumerated options, and Claim 12 ties to Table 1 compounds.
- Method-of-use anchor: Claims 15–18 target IDH1-mutant biology and explicitly name R132H/R132C plus multiple cancers. That supports enforcement against label-indication use and potentially combination regimens.
Vulnerability factors typical for this type of claim
- Overbreadth vs enablement/description risks: very broad Markush claims can be challenged if the specification does not support every branch.
- Prior art mapping risk: if other IDH1 inhibitors existed with similar scaffold and substitution patterns, the inventive step for wide genus claims can be attacked.
- Design-around risk: a generic or competitor can try to escape by changing scaffold attachment relationships rather than substituent-only modifications.
(Those are litigation-grade risk categories; they affect enforceability strategy but are not determinable from your provided excerpt alone.)
What is likely the infringement “map” for competitor compounds? (Practical coverage checklist)
A compound is in play for literal coverage if it:
- Matches Formula I or Formula II-a structural relationship in the patent (not provided in your text excerpt, but required for Claims 1 and 4).
- Contains ring A = 4–6 membered non-aromatic ring with 0–1 extra N/O/S and 1–2 substituents (R5) selected from the enumerated set.
- Uses substituent classes consistent with:
- R1 as C4–C6 carbocyclyl (optional R7 halo substitutions depending on claim)
- R2/R3 aryl or heteroaryl (with or without restrictions depending on claim tier)
- R4 alkyl/aryl/heteroaryl/aralkyl/heteroaralkyl with permitted substitution.
- If targeting method claims, the clinical use must involve IDH1 mutation producing R(-)-2-hydroxyglutarate generation, specifically R132H or R132C for Claims 16–18.
US regulatory and Orange Book positioning (what the patent landscape implies for generics/biosimilars)
Short answer: The claim set is for small molecules (compound genus and pharmaceutical compositions, not biologics). That means exclusivity pressure for future competitors typically runs through ANDA/Paragraph IV pathways rather than biosimilars.
Relevance to FDA pathways
- If an ANDA exists for an IDH1 inhibitor: Paragraph IV litigation would target FDA-listed drug patents. The most enforceable patents are typically those covering:
- the drug substance (compound/Formula claims)
- composition (formulation)
- method-of-use (therapeutic use tied to indication and target biology)
Method-of-use enforceability
Claims 15–18 can matter even if a generic product is chemically capable of treating the target, because the claim is tied to patient treatment of IDH1-mutant cancers and explicit R132H/R132C use.
How many separate claim “buckets” does this patent create (for litigation and licensing strategy)?
Short answer: At minimum, the claim structure creates three attack surfaces and two independent claim enforcement tracks.
Enforcement tracks
- Compound infringement (Claims 1–12; including Table 1 embodiments)
- Composition infringement (Claims 13–14)
- Method-of-use infringement (Claims 15–18)
Litigation leverage points
- If a competitor’s compound falls in the Formula II-a sub-genus, Claim 4–11 constraints can be used to narrow the claim construction.
- If a competitor uses the patent-covered compounds in an IDH1 R132H/R132C regimen for any listed cancer, Claims 15–18 give a direct method-of-use narrative.
What generic entry risks exist given these claims?
Short answer: Any generic entrant faces meaningful risk if:
- the approved reference product’s FDA-listed patents include US 9,474,779, and
- the generic compound falls within Formula I/II-a coverage, and/or
- the generic is marketed for R132H/R132C IDH1-mutant cancers covered by the method claims.
In practice: Paragraph IV strategies often focus on whether:
- the accused generic product is outside the literal scope (scaffold/design-around), or
- the patent is invalid (obviousness/enablement/anticipation), or
- the method-of-use is not infringed due to label carve-outs.
Key Takeaways
- US 9,474,779 is a broad Markush-style small-molecule patent covering Formula I compounds with wide latitude on ring A, aryl/heteroaryl groups, alkyl/aralkyl/heteroaralkyl groups, and substitution via R5/R6/R7.
- Claims 4–11 create a second, tighter sub-genus (Formula II-a) with enumerated R11 substituent options and additional constraints on R1 and R4.
- Claims 13–14 expand coverage to pharmaceutical compositions and combination therapy with a second cancer agent.
- Claims 15–18 provide enforceable method-of-use protection for IDH1 mutation–driven R(-)-2-hydroxyglutarate production, explicitly covering R132H and R132C across multiple cancer indications including glioblastoma, AML, melanoma, NSCLC, cholangiocarcinoma, MDS, MPN, and colon cancer.
- For competitive strategy: the claim set is structured to support both (i) compound-level infringement theories and (ii) indication-driven method-of-use enforcement.
FAQs
1) Does US 9,474,779 cover pharmaceutically acceptable salts and hydrates?
Yes. Claim 1 expressly includes pharmaceutically acceptable salts, tautomers, isotopologues, or hydrates.
2) Are heteroaryl groups allowed on R2/R3 under the broadest claim?
Yes. Claim 1 allows R2 and R3 to be independently optionally substituted aryl or optionally substituted heteroaryl. Claim 3 narrows that to aryl only.
3) What R5 substituents on ring A are explicitly allowed?
R5 includes halo, CF3, CN, OR6, N(R6)2, sulfone/sulfonamide motifs (SO2N(R6)2, SO2(alkyl), NR6SO2R6), various ester/carbonyl-containing groups, and allowed carbocycle/heteroaryl substituents, among others.
4) Which IDH1 mutations are explicitly covered in the method claims?
Claims 16–18 specify IDH1 R132H and IDH1 R132C.
5) Are the method claims limited to a single cancer type?
No. Claim 17 lists multiple cancers, including glioblastoma, AML, melanoma, NSCLC, cholangiocarcinomas, chondrosarcoma, MDS, MPN, and colon cancer.
References
- US Patent No. 9,474,779. (Claims 1–18 provided in user excerpt).
