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Patent landscape, scope, and claims: |
US Patent 11,420,968 Landscape and Claim- Scope Analysis: Formula (II) Spiro-Linked Bcl-2 Inhibitors
Executive summary: U.S. Patent 11,420,968 claims a broad, genus-style set of spirocyclic/heterocyclic small-molecule Bcl-2 inhibitors built on a constrained core: ring A is 1,4-phenylene (or closely related spiro-variants in dependent claims), ring B is N-linked heterocycle (often cyclic amines such as aziridine/azetidine/pyrrolidine/piperidine derivatives), and ring- and substituent-selectable R-groups generate a very large chemical perimeter. Independent claim 1 is the key breadth driver, using wide definition blocks for R1, R2, ring-A/ring-B structural ranges, and a highly variable linker/“tail” defined as R5 = -L5-CyC with flexible multiple bond-pattern and substituent allowances. Dependent claims then “pin” commercial-relevant embodiments, including numerous specific exemplified structures and an explicit Bcl-2 activity inhibition method (claims 37–38).
What does US 11,420,968 claim in independent claim 1? (Formula (II) compound-genus coverage)
Featured snippet answer: Claim 1 covers any compound meeting a Formula (II) skeleton where ring A is specified (phenyl/1,4-phenylene in the independent claim), ring B is an N-linked monocyclic heterocycle containing a nitrogen (with limited additional heteroatom options), and substitution variables (R1, R2, R5/CyC and their substituents) are broadly defined. It also covers pharmaceutically acceptable salts and stereoisomers.
1) Structural scaffold blocks
Claim 1 begins with: “A compound of Formula (II) or a pharmaceutically acceptable salt thereof, or a stereoisomer thereof”. The breadth is then created by defining three main variable regions:
(a) Ring A
- In claim 1: “ring A is a phenyl ring, which is 1,4-phenylene”
- Dependent claim 2 repeats the same: ring A is 1,4-phenylene.
(b) Ring B and connectivity
- Ring B is defined as:
- a monocyclic 4–9-membered heterocycle comprising one nitrogen as ring member, OR
- a monocyclic 4–9-membered heterocycle with one nitrogen plus an additional heteroatom selected from NH, O, S, SO, SO2 as ring members
- Ring B is N-linked to ring A.
This matters for infringement strategy because N-linkage is a hard connection requirement, while the identity of ring B members has a wide range.
(c) Substituent variable at the ring junction: R1 and R2
Claim 1 introduces two separate substitution regimes:
- R2: at each occurrence independently H, halogen, or C1–8alkyl optionally halogenated
- R1: a very wide menu of substituents (alkyl/alkenyl/alkynyl, cycloalkyl, heterocyclyl, aryl/heteroaryl, oxo, CN, NO2, OR1a, sulfonyl/amide/ester/amine-like functionalities, etc.), each optionally substituted with up to 4 substituents R1d/R1a/R1b/R1c (from large sets that include halogen, hydroxy, alkoxy, and further ring/aryl/heteroaryl options).
2) The “R5 tail” definition is the breadth multiplier
Claim 1 defines R5 = -L5-CyC.
(a) L5
- L5 is defined as a direct bond or a set of linker motifs including:
- -(CRaRb)t— (t = 1–7),
- patterns allowing unsaturation (e.g., “(CRaRb)t-1—(C≡C)—(CRaRb)v-1”),
- heteroatom linkers (O, S, S(O), SO2),
- carbonyl-containing connectors (C(O), C(O)O, OC(O)),
- amino/connectors like NRa plus carbonyl variations (NRaC(O) etc.),
- and imino/guanidino-like motifs (C(═NRa)NRb…).
This means the patent does not require a single rigid tail chemistry. It captures many tail connectivities that could match analogs.
(b) CyC
- CyC is cycloalkyl, heterocyclyl, aryl, or heteroaryl, optionally substituted with one or two substituents R5a.
- R5a is itself highly expansive: includes halogens, cyano, oxo, nitro, OR5b, SR5b, multiple carbonyl/amide/sulfonamide-like classes, and a broad set of alkyl and ring systems optionally substituted by halogen/hydroxy/alkoxy or further ring options.
(c) Explicit aromatic “benzo ring” closure condition
- Claim 1 includes a structural conditional: “two adjacent R5 on the phenyl ring together with the phenyl ring form a benzo ring”.
- That ring can be optionally substituted and includes heteroaryl closure logic.
(d) m
- m = 1–4, controlling the occurrence/positioning of R5 substitutions within the formula.
3) How claim 1 balances rigidity vs flexibility
- Rigid constraints:
- Ring A is fixed as 1,4-phenylene (in claim 1).
- Ring B must be N-linked to ring A and be monocyclic 4–9 ring size with nitrogen-containing rules.
- Flexibility:
- substitution breadth on R1 (including heteroatom-functional substituents),
- R5 tail connectivities and tail ring systems,
- R2 minimal set.
This is a classic “genus with broad substituent variable language” approach.
How narrow are the independent-claim constraints once you read them as infringement requirements?
Featured snippet answer: The enforceable “hard points” of claim 1 are likely the (i) 1,4-phenylene ring A, (ii) N-linkage to ring B, and (iii) the Formula (II) architecture requiring the R5 = -L5-CyC tail with defined linker options and substitution limits. Most other features are expanded by broad definition blocks.
Hard-point checklist (claim 1)
- Does the accused compound have a 1,4-phenylene ring A component?
- Is ring B monocyclic 4–9-membered and N-linked to ring A?
- Does the molecule include the Formula (II) region requiring R5 = -L5-CyC (with L5 from the specified motif list and CyC from the specified ring categories)?
- Are the substituent placements consistent with the occurrence constraints for m (1–4) and the optional substitution limits (typically “up to 1–4” for R1d/R1a/R1b/R1c, and “one or two” for R5a)?
If any of those core points fail, the infringement risk under claim 1 drops.
How do dependent claims narrow the claim 1 genus (ring A variants, ring B examples, and CyC pinning)?
Ring A narrowing (claims 3–4)
- Claim 3: “ring A is” a set of spiro A/B mono-spiro heterocycles with ring-size combinations (4/4, 3/5, 4/5, 4/6, 5/5, 5/6), containing one or two nitrogen or oxygen ring members.
- Claim 4 refers to a positional definition in ring A with starred positions.
Practical effect: claim 1 already fixes ring A to 1,4-phenylene; these dependent claims introduce additional ring A variants tied to claim 1’s formula language, indicating the patent family covers alternative ring-A presentations even if claim 1 emphasizes phenyl.
R2 narrowing (claim 9)
Ring B embodiment list (claim 5)
Claim 5 provides a concrete ring B list:
- aziridin-1-yl, azetidin-1-yl, pyrrolidin-1-yl, pyrrolidin-2-yl, piperidin-1-yl, azepan-1-yl, azocan-1-yl
- also: ring B is substituted with a phenyl group at position 2, and that phenyl can be optionally substituted at the ortho position with R1d.
Practical effect: this is how the patent likely anticipates actual commercial leads, giving multiple “entry points” for claim mapping.
R1d substitution exemplars (claims 10–11)
- Claim 10 defines a broad list for R1d.
- Claim 11 pinpoints examples: methyl, ethyl, isopropyl, propyl, methoxymethyl, propenyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, ethoxy, isopropoxy, amino, dimethylamino.
L5 and m variations (claims 13–14, 28)
- Claim 13: m = 1 and L5 is direct bond, -(CRaRb)t-, or -NRa- with t 1–7.
- Claim 14: L5 can be direct-bond or short polymethylene/heteroatom-separated linkers, or a specific “NH-(CRaRb)-(CH2)2” style.
- Claim 28: L5 can be direct bond, CH2, O-CH2, NH-CH2, or NH.
This narrows tail geometry and linker chemistry to match known analog scaffolds.
CyC pinning to specific ring systems (claims 15–22, 29–31)
Claims 15–22 and 29–31 specify CyC categories with example ring systems:
- CyC includes cycloalkyl/heterocyclyl optionally substituted.
- Claim 16 pins CyC to cycloalkyl types (monocyclic C3–8 or bridged cycloalkyl).
- Claim 17/18/19 pin heterocycle size and heteroatom count patterns.
- Claim 22: CyC substitution option tetrahydro-pyran-4-yl.
- Claim 29: enumerates specific CyC options (oxetan-2/3-yl, THF isomers, THP isomers, azetidin, pyrrolidin, piperidin variants).
- Claim 30: enumerates additional CyC options (1,3-dioxan isomers; morpholin isomers).
- Claim 31 and 39-like language: examples for R5a as oxetane/THF/tetrahydro-2H-pyran-4-yl/morphin-4-yl and conditions for when R5a is amide/OR/SO2R forms.
Practical effect: these dependent claims turn the genus into a set of chemotype families that are more likely to match marketed analogs and lead-optimization series.
Which concrete compounds are explicitly recited (claims 6–8 and 26, 33)?
Claim 26 (explicit large list) is the operational anchor
Claim 26 states the compound is selected from a very large enumerated list of specific chemical names and stereoisomers, including repeated patterns:
- a pyrrolo[2,3-b]pyridine-oxy substituent,
- a sulfonamide motif on a nitro-substituted phenyl,
- and a biphenyl carboxamide region,
- coupled to a pyrrolidine/azetidine/piperidine type substituted “ring B” moiety and a tetrahydro-2H-pyran-4-yl methylamino tail moiety in many embodiments.
This is a strong indication that claim scope is meant to cover:
- multiple ortho-substituted phenyl options on ring B,
- multiple halogen and CF3 patterns,
- and many ring-size swaps (pyrrolidinyl variants, azetidinyl, piperidinyl, spiro-heterocycles).
Claim 33 narrows to a single exemplified compound
Claim 33 recites a specific structure:
- 2-((1H-pyrrolo[2,3-b]pyridin-5-yl)oxy)-N-((4-((((1r,4r)-4-hydroxy-4-methylcyclohexyl)methyl)amino)-3-nitrophenyl)sulfonyl)-4-(2-((S)-2-(2-isopropylphenyl)pyrrolidin-1-yl)-7-azaspiro[3.5]nonan-7-yl)benzamide, plus salts.
This is the “single embodiment” claim often used for enforcement against a specific competitor compound.
What is protected beyond the compound claims: compositions and methods?
Pharmaceutical composition claims (35–36)
- Claim 35: composition with compound of claim 1 (or salt/stereoisomer) and pharmaceutically acceptable carrier.
- Claim 36: same but referencing claim 26 compound set.
These capture formulation risk for generic/analog companies if they sell the same compound in a standard carrier context.
Bcl-2 inhibition method claims (37–38)
- Claim 37: method for inhibiting Bcl-2 activity by administering a therapeutically effective amount of the compound of claim 1.
- Claim 38: method using the compound of claim 26.
These are important for:
- infringement theory against “use” even if composition claims are designed around different carriers,
- and potential enforcement against products with identical active ingredients.
How “wide” is the claimed chemical perimeter likely to be (qualitative scope quantification from language)?
Using only the claim language provided (not counting the full formula structure which is not printed here), the breadth can be approximated by the parameter cardinalities:
- Ring B: monocyclic 4–9-member heterocycles with one nitrogen, or one nitrogen plus a second heteroatom from NH/O/S/SO/SO2. This is a meaningful set, not just a single ring class.
- R1: includes common medicinal chemistry substituents and heteroaryl groups plus heteroatom-functional substituents (OR/SO2/amide/ester/urea/guanidine-like).
- R5 tail: CyC can be cycloalkyl, heterocyclyl, aryl, or heteroaryl, optionally substituted by one or two R5a substituents, with R5a itself including carbonyl/sulfonamide-like motifs.
- Linker L5: multiple connectivity classes including carbonyl-containing and heteroatom-containing linkers.
This structure indicates the patent is intended to block not only exact exemplified molecules but also “follow-on” analogs that keep:
- the same core connection framework,
- the ring A and ring B constraints,
- and the tail relationship to the core via the R5/L5 language.
Claim scope risk implications for competitors
1) Design-around levers
The most realistic design-around paths (based on where claim limitations are hard) are:
- replacing the 1,4-phenylene ring A with a different ring architecture not encompassed by claim 1’s ring-A definition,
- breaking the N-linked relationship between ring A and ring B,
- altering the tail region so that R5 is not in the allowed -L5-CyC patterns (e.g., linker chemistry outside L5 set, or CyC category outside allowed cycloalkyl/heterocyclyl/aryl/heteroaryl as defined),
- or using a ring-B system not meeting the monocyclic 4–9 and nitrogen-containing constraints.
2) Why “R5” analogs are still risky
Even if a competitor changes tail ring types or substituents, claim 1’s R5 language is broad enough to sweep many analog modifications, especially where changes are limited to:
- swapping among cycloalkyl/heterocycle/aryl/heteroaryl,
- placing one or two substituents,
- switching between common linker types in the allowed lists (direct bond, -(CRaRb)t—, heteroatoms, carbonyls, amines, etc.).
Key Takeaways
- Independent claim 1 is a broad genus driven by fixed ring-A identity (1,4-phenylene) and N-linked monocyclic N-containing ring-B plus very expansive substituent options.
- R5 = -L5-CyC is the main breadth engine, with wide allowable linker patterns and wide allowable tail ring systems and substituents.
- Dependent claims narrow into specific chemical families by pinning ring-B examples, linker L5 options, and CyC/tail sub-structures.
- Method claims explicitly cover Bcl-2 activity inhibition via administration of claim 1 or claim 26 compounds.
- Claim 26 is operationally critical because it enumerates a large set of specific exemplified structures and stereoisomers, making mapping to real competitor products more direct.
FAQs
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Does US 11,420,968 cover stereoisomers and salts?
Yes. Claim 1 and claim 26 include “pharmaceutically acceptable salt thereof, or a stereoisomer thereof.”
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What is the biggest structural feature competitors must avoid to reduce claim 1 risk?
The fixed ring A = 1,4-phenylene and the N-linked ring-B relationship, plus maintaining the R5 tail pattern defined as -L5-CyC.
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Are Bcl-2 use claims present in US 11,420,968?
Yes. Claims 37–38 claim methods for inhibiting Bcl-2 activity.
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Which dependent claims provide “pin-down” of linker chemistry?
Linker definition constraints appear in claims 13–14 and 28 (including direct bond, CH2, O-CH2, NH-CH2, NH).
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Do the claims include pharmaceutical compositions?
Yes. Claims 35–36 claim pharmaceutical compositions with standard pharmaceutically acceptable carriers.
References (APA)
No external sources were cited because only the claim text provided in the prompt was used.
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