United States Patent 8,642,608: Scope of Claims and Patent Landscape for the VEGFR/EGFR Quinazoline
US Patent 8,642,608 claims a method of treatment using a specific quinazoline small-molecule to inhibit VEGF receptor (VEGFR) tyrosine kinase and/or EGF receptor (EGFR) tyrosine kinase in warm-blooded animals with cancer associated with VEGF or EGF, with scope driven by (i) the exact compound, (ii) VEGF/EGF association and solid tumor framing, and (iii) optional narrowing to tumors allegedly significantly dependent on VEGF and/or EGF. The patent landscape for this activity domain is crowded, but this patent’s practical enforceability centers on the particular compound identity and method-use boundaries rather than broad target inhibition per se.
What is the claimed invention in US 8,642,608?
The independent claim is a VEGFR/EGFR inhibition method:
- Claim 1:
“A method of inhibiting vascular endothelial growth factor (VEGF) receptor tyrosine kinase activity or endothelial growth factor (EGF) receptor tyrosine kinase activity in a warm-blooded animal suffering from a cancer associated with VEGF or EGF, comprising administering an effective amount of:
4-(4-bromo-2-fluoroanilino)-6-methoxy-7-(1-methylpiperidin-4-ylmethoxy)quinazoline
or a pharmaceutically acceptable salt, where the cancer is a primary or recurrent solid tumor.”
This is a classic product-defined substance, method-of-use claim: the active is defined by chemical structure/name, while the indication is solid tumors connected to VEGF and/or EGF biology.
How broad are the claims by target and indication?
Claim architecture (1 to 11)
-
Target scope
- Claim 1 covers inhibition of VEGFR activity and/or EGFR activity.
- Dependent claims (3–5) do not change target identity; they narrow by which growth dependency the tumor has.
-
Indication scope
- Claim 1 covers primary or recurrent solid tumors tied to VEGF or EGF.
- Claims 6, 8, 9, 10, 11 narrow tumor types under the “significantly dependent on VEGF” concept.
- No dependent claim lists an EGF-dependent tumor type; instead, EGF dependence appears as a general narrowing concept in claim 4 and in combination in claim 5.
Breadth of “warm-blooded animal”
- Claim 2 narrows to human, but Claim 1 already covers a wide animal universe. In enforcement terms, Claim 2 is commercially useful because clinical development and marketing typically occur in humans.
Breadth of “cancer associated with VEGF or EGF”
- Claim 1 uses an association standard: the animal is “suffering from a cancer associated with VEGF or EGF.”
- Claims 3–5 further narrow using the phrase “significantly dependent” on VEGF and/or EGF for growth and/or spread.
- This two-tier construct matters:
- Claim 1 supports a less biomarker-restricted theory (association).
- Claims 3–5 create a more test/biology-constrained reading (significant dependency).
What is the compound scope: exact identity locks enforceability
The claimed active is a single, precisely identified quinazoline:
- 4-(4-bromo-2-fluoroanilino)-6-methoxy-7-(1-methylpiperidin-4-ylmethoxy)quinazoline
- plus pharmaceutically acceptable salts
This is a narrow chemical scope by identity rather than class. For infringement analysis, the critical question is whether a challenger’s proposed compound is:
- the same compound (same structure),
- or a salt form within “pharmaceutically acceptable salts,”
- or an equivalent that avoids the claim language (structural design-around).
Because Claim 1 explicitly recites a named compound, any enforcement that relies on “substantially similar” chemistry is limited by the claim’s literal language.
Salt coverage
- The “pharmaceutically acceptable salt thereof” language expands coverage beyond the free base form, including counterion variations that qualify as pharmaceutically acceptable salts.
How do the dependent claims narrow the method?
Which tumor dependency definitions narrow scope most
Dependent claims create two types of narrowing: biology and tumor site.
VEGF dependency concept
- Claim 3: solid tumor “significantly dependent on VEGF for its growth and/or spread.”
- Claim 6: among VEGF-dependent tumors, specifies:
- Claim 8–11: specified VEGF-dependent tumors:
- breast (Claim 8)
- lung (Claim 9)
- vulva (Claim 10)
- skin (Claim 11)
EGF dependency concept
- Claim 4: solid tumor “significantly dependent on EGF for its growth and/or spread.”
- Claim 5: solid tumor “significantly dependent on VEGF and EGF for its growth and/or spread.”
Notably, there is no dependent claim listing EGF-dependent tumor sites specifically; EGF is used as a generic dependency filter.
What does “results in inhibition or slowing of the growth” add
- Claim 7: administration “results in inhibition or slowing of the growth of the primary or recurrent solid tumor.”
This is method-effect language. Practically, it does not broaden the claim, but it can help tie the method to measurable pharmacology and reduce arguments that the claim is purely theoretical.
What is the practical enforcement envelope?
The patent most naturally reads on:
- A regimen where a patient has a primary or recurrent solid tumor,
- in which clinicians assert or establish that the tumor is associated with VEGF or EGF (Claim 1), or significantly dependent on VEGF and/or EGF (Claims 3–5),
- and where the administered small molecule is the exact quinazoline (or its acceptable salt).
Infringement usually turns on two axes:
- Compound identity (literal chemical match or salt coverage).
- Method use facts (tumor association/dependency and that the patient received an effective amount).
How does this claim set compare to typical VEGFR/EGFR patents?
In the VEGFR/EGFR space, many patents claim:
- broad kinase inhibitors (chemical genus) or
- broad “use for inhibiting VEGFR/EGFR in cancer” method language.
US 8,642,608 differs by:
- using a single specified compound rather than a broad chemical class, and
- using VEGF/EGF association and dependency rather than a single fixed indication.
That combination narrows chemical design-around risk for competitors only if they also want to avoid these exact structural features.
Is the patent a “reach-through” claim to any VEGFR/EGF use?
No. Claim 1 is not a target-any-inhibitor claim. It is a specific compound administered for a specific kind of cancer (primary or recurrent solid tumor) tied to VEGF or EGF.
So competitors targeting VEGFR/EGFR with other chemotypes can often avoid literal infringement by changing the active ingredient.
What is the patent landscape around US 8,642,608?
Landscape framing for diligence (what to map)
To map the landscape around this method-use patent, diligence typically clusters patents into three buckets:
- Chemical patents for the named quinazoline (or closely related analogs)
- Method-of-use patents for VEGFR/EGFR inhibitors in solid tumors
- Combination and regimen patents (sequence, dosing, with other agents)
Where this patent likely sits
Given Claim 1’s structure, US 8,642,608 sits most plausibly as:
- a later-stage or formulation/enhancement style method-use patent linked to a specific VEGFR/EGFR inhibitor scaffold, with tumor dependency language and site examples.
However, the exact prosecution family, priority chain, and related US publications cannot be validated from the claim text alone.
What specific claim language drives design-around risk?
Design-around strategies usually target one or more of these claim anchors:
| Claim anchor |
What it means |
Typical design-around path |
| Exact compound identity |
Must administer the named quinazoline (or acceptable salt) |
Use a different chemical scaffold or avoid the precise structural substitutions |
| “Pharmaceutically acceptable salt” |
Salt forms still infringe if they fall within acceptable salt definition |
Choose non-salt forms or avoid salt types that would qualify as acceptable |
| “Primary or recurrent solid tumor” |
Limits beyond hematologic malignancies |
Avoid use claims tied to “primary or recurrent solid tumor” or pursue different clinical contexts |
| “associated with VEGF or EGF” |
Requires biological relevance |
Pursue indications without VEGF/EGF association in the way the label/clinical justification frames it |
| “significantly dependent” |
Implies biological dependency threshold |
Conduct indications without evidence supporting “significant dependency” framing |
What claim-scope scenarios are most relevant for competitors?
Scenario A: same compound, different VEGF/EGF framing
If a competitor uses the same compound but targets a malignancy not characterized as VEGF/EGF-associated or not “primary or recurrent solid tumor,” they still face Claim 1 risk if their clinical justification and patient selection fit the language.
Scenario B: different compound, same indications
If the active ingredient differs from the named quinazoline (and not a covered salt), literal infringement risk drops materially because Claim 1 is substance-defined.
Scenario C: combination regimens
If the competitor combines the named compound with other therapies, infringement can still attach if the method includes the claimed administration and the patient selection fits the VEGF/EGF dependency constructs.
Claim-by-claim scope digest (operational view)
| Claim |
Scope element |
What is covered |
| 1 |
Independent |
Warm-blooded animal with VEGF- or EGF-associated cancer; administer effective amount of the named quinazoline (or acceptable salt); cancer is primary or recurrent solid tumor; method inhibits VEGFR or EGF receptor tyrosine kinase activity |
| 2 |
Dependent |
Human patients |
| 3 |
Dependent |
Solid tumor significantly dependent on VEGF for growth/spread |
| 4 |
Dependent |
Solid tumor significantly dependent on EGF for growth/spread |
| 5 |
Dependent |
Solid tumor significantly dependent on both VEGF and EGF for growth/spread |
| 6 |
Dependent + site |
VEGF-dependent tumor of colon |
| 7 |
Dependent + effect |
Administration results in inhibition or slowing of tumor growth |
| 8 |
Dependent + site |
VEGF-dependent tumor of breast |
| 9 |
Dependent + site |
VEGF-dependent tumor of lung |
| 10 |
Dependent + site |
VEGF-dependent tumor of vulva |
| 11 |
Dependent + site |
VEGF-dependent tumor of skin |
Key Takeaways
- US 8,642,608 is substance-defined: infringement depends on administering 4-(4-bromo-2-fluoroanilino)-6-methoxy-7-(1-methylpiperidin-4-ylmethoxy)quinazoline (or acceptable salts), not on generic VEGFR/EGFR inhibition.
- Indication scope is method-of-use framed to primary or recurrent solid tumors with VEGF and/or EGF association, narrowed by “significantly dependent” language in dependent claims.
- Tumor site coverage exists only for VEGF-dependent examples: colon, breast, lung, vulva, and skin appear as specific dependent claim embodiments; EGF-dependent tumor sites are not enumerated.
- The enforceable envelope is most threatened by copying the active ingredient plus labeling/patient-selection narratives consistent with VEGF/EGF dependency.
FAQs
1. Is US 8,642,608 a broad “any VEGFR/EGFR inhibitor” patent?
No. Claim 1 requires administering the specific quinazoline or a pharmaceutically acceptable salt.
2. Does the patent cover both VEGFR and EGFR inhibition in the same claim?
Yes. Claim 1 covers inhibiting VEGFR tyrosine kinase activity or EGF receptor tyrosine kinase activity.
3. What cancer types are explicitly listed?
For VEGF-dependent tumors: colon, breast, lung, vulva, and skin (Claims 6, 8–11). Claim 1 also covers primary or recurrent solid tumors more generally.
4. Does Claim 7 require a measurable outcome?
It requires that administration “results in inhibition or slowing of the growth” of the tumor, which ties the method to tumor growth suppression.
5. Where is the strongest narrowing versus Claim 1?
Claims 3–5 narrow by tumor biology (“significantly dependent on VEGF and/or EGF”). Claims 6 and 8–11 further narrow by tumor site under the VEGF-dependent construct.
References
[1] United States Patent No. 8,642,608. “Method for inhibiting vascular endothelial growth factor receptor tyrosine kinase activity and/or EGF receptor tyrosine kinase activity.” (Claims provided in prompt).
