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Patent landscape, scope, and claims: |
Scope and US Patent Estate Analysis for US Patent 8,680,124 (KIT-resistance oncology dosing of “Formula I” compound)
US 8,680,124 is a US-method-of-treatment patent that claims administration of a single small-molecule “Formula I” (chemical name given in the claims) for treating cancers that acquired resistance to KIT tyrosine kinase inhibitors, with claim scope anchored to (i) the resistance construct (initial sensitivity to KIT inhibitor followed by acquired resistance), (ii) the resistance trigger (explicit imatinib and a set of named KIT inhibitors), and (iii) specific KIT secondary mutations (kinase catalytic domain; exons 13/14/17; specific residue positions and enumerated mutation/deletion sets). The estate is structurally a “drug+biomarker method” fence: it is not a composition patent, so it targets prescribers and “use” infringement scenarios where clinicians administer the compound to patients with the defined resistance and mutation characteristics.
What is US Patent 8,680,124 claiming: method-of-treatment for KIT inhibitor–resistant cancers?
Bottom line: The patent claims a method of treating cancer by administering the “Formula I” compound to subjects whose cancer became resistant to KIT inhibitors, including specific resistance pathways associated with KIT secondary mutations in the kinase catalytic domain.
What is the claimed drug (the only active)
Across the independent claim set (notably claims 1, 15, 26, 27, 29-34), infringement depends on administering:
- 4{4-[3-(4-chloro-3-trifluoromethylphenyl)-ureido]-3-fluorophenoxy}-pyridine-2-carboxylic acid methylamide
- with claim language capturing all polymorphs, hydrates, pharmaceutically acceptable salts, metabolites, prodrugs/prodrug forms (claims vary between “metabolites/prodrugs/solvates”), and combinations.
IP impact: The breadth around polymorphs/salts/prodrugs covers many physical forms and salt selection, but the legal boundary remains: the administration must be of the claimed structure (or a claimed “including all…” variant that is treated as within the same patent’s covered scope by the claim wording).
What resistance “story” is required?
Claim 1 requires:
- cancer initially sensitive to a KIT tyrosine kinase inhibitor
- then acquired resistance to that KIT inhibitor
- method includes administering Formula I.
Claims 15 and 26 similarly require primary/secondary KIT mutation association with acquired resistance, and claim 26 further ties to resistance to imatinib mesylate (and salts).
What cancers are covered?
Claim 3 lists a long set, including:
- GIST (malignant and benign), mesenchymal intestinal tumors
- CML (and multiple leukemia descriptors)
- SCLC
- breast cancer and neuroblastoma
- plus many other named cancers via the extremely broad genus list in claim 28 (see below).
IP impact: The patent uses disease-agnostic language in parts (claim 29, 28) and mutation-centric in parts (claims 5-14, 17-25). In practice, mutation status is the operational gate for strongest enforcement.
What mutation facts tighten the method scope?
Claims 5-14 (and mirrored claims 17-25) add a biomarker constraint:
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acquired resistance is associated with a secondary mutation in a KIT gene mutated in the primary tumor
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secondary mutation in the kinase catalytic domain
-
mutation locations:
- Exons 13, 14, and/or 17
- residue ranges: 650-654, 670-674, 816-824 (and explicit residue numbers including 654, 670, 716, 816, 820, 822, 823)
-
enumerated mutation sets include (non-exhaustive list exactly in your provided claims):
- V654A (Exon 13)
- T670I, T670E
- D716N
- S709F (Exon 14)
- D816G, D816E
- D820E, D820Y, D820G
- N822K
- Y823D
- deletions and substitutions in/near residue regions including multiple enumerated deletion windows (e.g., 557-558, 551-555, 550-558, 559-560, 557-561, 554-558, 552-557), and specific single-residue variants at 559 (V559D/A/G, W557S/R, W557S alone or with deletion windows), plus L576P.
-
combination claim example:
- claim 14: deletion of residues 557-558 and at least one of V654A, T670I, D820Y, N822K, Y823D.
IP impact: The mutation list gives the patent enforceable specificity. If a generic or competitor develops a product intended for the same clinical niche but patients’ mutation profiles differ (or the drug is used without demonstrating the required mutation association), infringement arguments weaken against the mutation-dependent dependent claims. Conversely, where secondary KIT mutations match the enumerated set, the patent’s biomarker fence strengthens.
Claim 2: resistance relative to named KIT inhibitors
Claim 2 specifies that acquired resistance is to one of:
- imatinib mesylate (and salts)
- PP1(… ) (a research compound identifier)
- MLN518 (CT53518)
- PD180970
- SU112481
- SU5416
- SU5414
- SU6597
- SU6663
- SU6561
IP impact: This makes the resistance context more defensible by tying the “acquired resistance” narrative to known KIT inhibitors, limiting arguments that the resistance was not “to KIT TKIs” as contemplated.
How broad are the claims: which elements are mandatory vs optional?
Bottom line: The independent claims are “drug administration + KIT-inhibitor resistance context.” Dependent claims progressively add mutation specificity, disease narrowing, and particular prior therapy.
Mandatory elements in the strongest independent claim pathways
- Administer Formula I (polymorph/salt/prodrug coverage in the claim language)
- Treat cancer in a subject
- Cancer acquired resistance to KIT tyrosine kinase inhibitor
- and/or associated with primary/secondary KIT mutations associated with resistance
Optional/added constraints in dependent claims
- Specific prior inhibitors (claim 2)
- Specific cancer types (claims 3, 28)
- Secondary mutation must be in the catalytic domain (claims 5-6, 17)
- Exons and residue positions (claims 7-12, 18-19, 20-22)
- Enumerated mutation and deletion set membership (claims 12-14, 23-25)
- Imatinib-resistance framing (claims 4, 26)
What is the scope of “Formula I” equivalents: do polymorphs, salts, prodrugs expand coverage?
Your provided claim text includes explicit “including all polymorphs, hydrates, pharmaceutically acceptable salts, metabolites, prodrugs/ester prodrugs, solvates.” In claim 15/26 it also includes “ester prodrugs.” This typically creates multiple infringement pathways where a competitor’s commercial form differs from the originally exemplified solid state.
Claim scope implication for lifecycle strategy:
- Switching to a different salt form, hydrate, or prodrug prodrug/ester form does not remove coverage if the competitor’s product is still within “including all…” scope.
- If a competitor uses a different chemical structure outside the Formula I definition, the patent does not cover it on your provided claim text.
Which cancers are covered the most: how do the “GIST/CML/leukemia” lists affect enforceability?
Bottom line: Claim 3 provides targeted oncology focus (GIST, CML, mast cell tumor, SCLC, germ cell, breast, neuroblastoma). Claim 28 is a broad oncology genus list that functionally expands the patient pool, but the mutation-dependent claims remain the strongest leverage where KIT secondary mutations are present.
The “GIST/CML anchor”
- GIST appears repeatedly (malignant and benign; accelerated phase and unresectable/metastatic GIST language appears in claim 30).
- CML appears broadly.
Broad “oncology capture” in claim 28
Claim 28 contains a very large set of oncology terms including many tumor types, stages, and leukemia subtypes, plus non-malignant disease descriptors like “Pulmonary Fibrosis,” and “Rheumatoid Arthritis,” and “Metaplasia.” That breadth is unusual for a clean KIT-resistance method claim, but it can still create cover if the claim is construed to include those indications.
When does the patent lose exclusivity: expiration and potential terminal disclaimer effects?
No determination is possible from the provided record. US patent term end date depends on:
- filing date,
- any priority date, and
- patent term adjustment/extension, plus any terminal disclaimer.
Your prompt provides claim text only, not the bibliographic data needed to compute exclusivity loss for US 8,680,124.
What patents protect the same KIT-resistance compound: how would US 8,680,124 fit in a typical “drug + biomarker” family?
No patent family members, continuation patents, divisional claims, or related filings are identified in your prompt. Without bibliographic anchors for 8,680,124 (application number, priority, assignee, related US/PCT publications), the landscape cannot be constructed without risking incorrect inclusion or omission.
Which legal hooks are embedded in the claim: method claims vs product claims and infringement triggers?
Bottom line: 8,680,124 is written as a method of treating. Enforcement typically focuses on:
- prescribing and administering the compound to patients meeting the claimed clinical biomarker profile (secondary KIT mutation and acquired resistance).
- evidentiary burdens tie to patient records, sequencing results (exon/residue mutation facts), and documentation of prior KIT inhibitor sensitivity/resistance.
How the mutation language can support litigation
Claims 5-14 and 17-25 explicitly require:
- “secondary mutation in KIT gene”
- location constraints (catalytic domain; exons 13/14/17)
- specific residue-based enumerations.
That creates a litigation pathway where plaintiff can present:
- genotyping reports,
- prior treatment histories showing acquired resistance to a KIT inhibitor,
- dosing records showing administration of the Formula I compound.
How mutation coverage can limit generic entry risk
If a generic product is used in the same disease setting but:
- patients’ KIT secondary mutations are not within the enumerated sets, or
- the clinical narrative does not establish acquired resistance to a KIT inhibitor in the contemplated way,
then the dependent claims become harder to prove. However, independent claims (claim 1/15/26/27/29/30-32) still require acquired resistance and administration of Formula I; mutation specifics mainly strengthen dependent claim provability.
What generic entry risks exist for KIT inhibitor–resistant GIST/CML patients?
No actionable generic entry scenario can be generated from your provided information. A credible launch-risk map requires:
- identification of the compound’s market status,
- the Orange Book listing status and listed patents/expiration,
- any Paragraph IV challenges tied to the compound,
- court cases and settlement agreements.
Your prompt provides none of that.
What is the Orange Book status of US 8,680,124?
Cannot be determined from the provided information. Orange Book status requires the marketed drug name and Orange Book listing for the active ingredient and dosage form, plus the listed patents and their associated claims.
Patent strength score: how enforceable are the claims on their face?
Face-based enforceability (based strictly on provided claim language):
- Strength: High where the accused conduct can be tied to the enumerated secondary KIT mutations and resistance context. The claim language is granular on mutation residue positions and deletion windows.
- Risk to enforcement: Moderate where accused use is in the same oncology niche but the patient’s mutation pattern differs from the enumerated catalytic-domain set or where acquired resistance is not documented as stemming from prior KIT inhibitor therapy matching the claim constructs.
- Form-variant risk to a competitor: Lower. The “including all polymorphs, hydrates, salts, metabolites, prodrugs/solvates” language expands coverage across common formulation choices.
Key Takeaways
- US 8,680,124 is a method-of-treatment patent centered on administering a single Formula I compound to treat cancers that were initially sensitive to KIT TKIs and then developed acquired KIT inhibitor resistance.
- The strongest claim layer adds KIT secondary mutation requirements: kinase catalytic domain, exons 13/14/17, and enumerated residue/mutation/deletion sets (examples include V654A, T670I/T670E, D716N, S709F, D816G/D816E, D820E/D820Y/D820G, N822K, Y823D, plus deletion windows like 557-558 and other specified deletion/substitution patterns).
- The disease scope ranges from targeted oncology (GIST, CML, mast cell tumor) to a very broad list of cancer terms, which can expand the patient pool, but biomarker-dependent claims anchor enforcement strength.
- “Including all polymorphs/hydrates/salts/prodrugs/solvates/metabolites” provides broad coverage across solid-state and prodrug variants, shifting design-around risk away from formulation-only changes.
- Exclusivity timing, Orange Book status, Paragraph IV posture, and the broader patent landscape cannot be established from the claim text alone.
FAQs
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Do the claims cover salt and hydrate forms of the Formula I compound?
Yes, the claim text includes “all polymorphs, hydrates, pharmaceutically acceptable salts” as within the scope.
-
Is KIT secondary mutation required in all claims?
No. Independent claims recite acquired KIT inhibitor resistance; dependent claims add secondary KIT mutation specifics (exon/residue/deletion/enumerated mutation sets).
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Which KIT exons are called out for the secondary mutations?
Exons 13, 14, and/or 17.
-
Does the patent limit the prior KIT inhibitor to imatinib only?
No. Claim 2 enumerates multiple KIT inhibitors beyond imatinib mesylate.
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Can a competitor avoid infringement by using a different formulation?
The claim language captures polymorphs, hydrates, salts, and certain prodrug/solvate variants. Design-around would require changing the covered chemical entity rather than switching common physical forms.
References
- US Patent 8,680,124 (claims as provided in the prompt).
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