United States Patent 8,658,643: What Do the Claims Actually Cover?
US Drug Patent 8,658,643 is a method-of-treatment patent that ties efficacy to inhibition of “Met kinase” and claims multiple specific chemical salts/forms of two closely related kinase inhibitors.
The independent claim is framed as treatment (not prevention) and is supported by dependent claims that broaden disease scope across solid tumors and hematologic malignancies.
Independent claim structure (Claim 1)
Claim 1 covers:
- Method: “A method for treating a disease which is influenced by inhibition of Met kinase,” where:
- “treating does not include prevention”
- Administration: administering an effective amount
- Disease eligibility: “a subject having said disease”
- Drug identity: one of the following compounds, including specific salt forms and an expanded “tautomer or stereoisomer” fallback.
Claim 1 drug list (A1 to A14)
Two core scaffolds appear:
1) 2H-pyridazin-3-one scaffold (A1–A6)
2) benzonitrile-dihydropyridazinyl scaffold (A7–A14)
A1–A6: 6-(1-Methyl-1H-pyrazol-4-yl)-2-{3-[5-(2-morpholin-4-ylethoxy)pyrimidin-2-yl]-benzyl}-2H-pyridazin-3-one (salt forms)
- A1 sulfate
- A2 mesylate
- A3 besylate
- A4 p-tosylate
- A5 fumarate
- A6 maleate
A7–A14: 3-(1-{3-[5-(1-Methylpiperidin-4-ylmethoxy)pyrimidin-2-yl]benzyl}-6-oxo-1,6-dihydropyridazin-3-yl)benzonitrile (salt forms)
- A7 hydrochloride monohydrate
- A8 hydrobromide
- A9 mesylate
- A10 besylate
- A11 malate
- A12 fumarate
- A13 maleate
- A14 p-tosylate
- plus “a tautomer or stereoisomer thereof.”
What this means for scope
- Claim 1 is not a broad “any Met inhibitor” claim.
- It is a compound-specific method claim with a salt/form play that includes multiple counterions plus tautomer/stereoisomer language.
How dependent claims narrow and expand use
The dependent claims are mostly disease-type variants and specific compound embodiments.
Disease categories claimed
Claims 2–7 (and mirrored later in claims 13–18) cover:
- Claim 2: “solid tumour”
- Claim 3: solid tumors from enumerated tissues
- examples from the list include: squamous epithelium, bladder, stomach, kidneys, head and neck, oesophagus, cervix, thyroid, intestine, liver, brain, prostate, urogenital tract, lymphatic system, larynx, lung
- Claim 4: additional enumerated examples including:
- monocytic leukaemia, lung adenocarcinoma, small-cell lung carcinomas, pancreatic cancer, glioblastomas, breast carcinoma
- Claim 5: overlapping/expanded solid tumor list including:
- lung adenocarcinoma, small-cell lung carcinomas, pancreatic cancer, glioblastomas, colon carcinoma, breast carcinoma
- Claim 6: “tumour of the blood and immune system”
- Claim 7: blood/immune tumors including:
- acute myeloid leukaemia, chronic myeloid leukaemia, acute lymphatic leukaemia, chronic lymphatic leukaemia
Combination therapy boundary
- Claim 8: “further comprising administering a pharmaceutically active compound, which is not a compound of claim 1.”
- This preserves combination-room while keeping the Met-inhibition drug as a required component.
Compound-specific dependent claim embodiments
- Claim 9: repeats Claim 1 drug list with the same A1–A14 inventory (this functions as additional support for embodiments).
- Claim 10: specifies A7 (hydrochloride monohydrate) for a method under Claim 1.
Claims 11–18 repeat the same concept but shift from “treating” to “stabilizing or improving clinical symptoms”
- Claim 11: “A method for stabilizing or improving the clinical symptoms” of a Met-influenced disease, again explicitly not prevention.
- Claims 12 and 14–16 and 18: specify A7 hydrochloride monohydrate and variants, with identical disease lists in substantially the same form.
Practical implication
This is a dual-coverage strategy:
- One set protects therapeutic treatment language (Claim 1).
- Another set protects clinical benefit/stabilization language (Claims 11–18).
That can matter in enforcement if a defendant argues something like “not treatment” but still claims symptom improvement.
What Is the Likely Patent Coverage Envelope? (Scope-by-Requirement)
Core “must-have” elements
To infringe, an accused method generally must satisfy all of:
- A disease influenced by inhibition of Met kinase
- A subject with the disease (not prophylaxis)
- Administration of an effective amount of one of the listed compounds (A1–A14, plus tautomer/stereoisomers fallback)
- The method is either:
- “treating does not include prevention,” or
- stabilizing/improving clinical symptoms (depending on which claim family is asserted)
“What you can design around” (based on claim text)
From a claim-construction standpoint, the design-around levers are:
- Met inhibitor class substitution alone likely fails if the accused drug is not one of A1–A14.
- Salt-form substitution can fail because A1–A14 includes many salts and “tautomer or stereoisomer.”
- Indication shift alone may fail because disease lists are broad and include many tumor types.
- Prophylaxis labeling can help because “treating does not include prevention” is explicit.
However, the patent landscape analysis below cannot be completed with the necessary factual certainty from your prompt alone.
Patent Landscape for US 8,658,643: What Can and Cannot Be Determined From Provided Data
A true “landscape” requires at least one of:
- the application number / priority
- the assignee / inventors
- the publication number(s) (WO/US published applications)
- family members
- prosecution history, claim amendments, and expiration / terminal disclaimer
- overlap against co-owned patents or competitors
Your input provides only the claim text and the patent number. It does not provide enough identifiable bibliographic data to map:
- the patent family boundaries,
- expiration dates,
- whether this is a late-stage continuation or method-only,
- or which earlier patents disclose the same compound class.
Under these constraints, a complete, accurate landscape cannot be produced.
Key Takeaways
- US 8,658,643 is a compound-specific Met-kinase inhibition method patent with disease scope spanning solid tumors and hematologic malignancies.
- The claims require administration of one of the listed salts/forms (A1–A14) of two related small molecules, including “tautomer or stereoisomer” coverage.
- The claim set is split between “treating” and “stabilizing or improving clinical symptoms,” preserving enforcement options depending on how clinical benefit is characterized.
- A full patent landscape (family mapping, expiration, litigation/INPADOC status, and freedom-to-operate conflicts) cannot be completed from the claim text alone.
FAQs
1) Does US 8,658,643 cover any Met inhibitor?
No. It requires use of one of the listed A1–A14 compounds (with tautomer/stereoisomer fallback).
2) Is prevention covered?
No. The claims state that “treating does not include prevention.”
3) What disease areas are explicitly listed?
Both solid tumors (numerous tissue origins) and blood/immune system tumors, including acute and chronic leukemias.
4) Does combination therapy fall within the claims?
Yes, if a pharmaceutically active compound is co-administered, as long as it is “not a compound of claim 1,” while the claim-1 compound is still administered.
5) What is the most important structural risk for competitors?
The breadth of salt/form coverage (A1–A14) plus “tautomer or stereoisomer” language tied to Met kinase influenced disease.
References (APA)
[1] US Patent 8,658,643 (claim text provided in prompt).
