US Patent 11,091,439 (malate salt of N-(4-{[6,7-bis(methyloxy)quinolin-4-yl]oxy}phenyl)-N′-(4-fluorophenyl) cyclopropane-1,1-dicarboxamide): claim scope, key limitations, and U.S. patent landscape
US 11,091,439 claims a specific compound class tied to one exact stereochemically defined malate salt form of a cyclopropane-1,1-dicarboxamide bearing a quinoline-4-yl ether substituted with 6,7-bis(methyloxy). The claims are narrowly framed as product-by-composition: (i) the exact free-base/acid-base structure plus (ii) malate salt status plus (iii) crystallinity; and dependent claims further pin to DL-, L-, or D-malate. This is a classic “salt form” fence, and its enforceable scope maps to crystalline malate salts of the stated molecule, not to other salts, amorphous forms, solvates, hydrates, or different stereochemical acid forms not expressly claimed.
What is US Patent 11,091,439 claim scope and what exact chemical entity does it cover?
Short answer: The patent covers crystalline malate salts of a single, fully specified active compound:
N-(4-{[6,7-bis(methyloxy)quinolin-4-yl]oxy}phenyl)-N′-(4-fluorophenyl) cyclopropane-1,1-dicarboxamide, where the acid is malic acid in crystalline salt form.
Claim 1: the independent product-by-structure + salt + crystallinity gatekeeper
Claim 1 reads (substance-level):
- Target API identity is fixed:
N-(4-{[6,7-bis(methyloxy)quinolin-4-yl]oxy}phenyl)-N′-(4-fluorophenyl) cyclopropane-1,1-dicarboxamide
- Counterion/acid is fixed: malate salt
- Physical form limitation is fixed: “crystalline”
Practical enforceability meaning
- A competitor must practice the same active moiety (same substitution pattern, ring systems, and amide connectivity) and present it as a malate salt that is crystalline.
- If a product is non-crystalline (amorphous) malate, claim 1 is not automatically met.
- If a product is other malate stereochemical form it may still fall within claim 1 if the salt is crystalline and still “malate salt” as broadly defined. Dependent claims tighten stereochemistry further.
Claims 2–5: stereochemical malate species and their narrower capture
Claim 2 adds: (DL)-malate salt (crystalline malate).
Claims 3–5 allocate stereochemistry:
- Claim 3: (L)-malate or (D)-malate
- Claim 4: (L)-malate
- Claim 5: (D)-malate
Scope consequences
- If a competitor uses a specific enantiopure malate form, it can be pulled into claim 4 (L) or claim 5 (D) if the API matches exactly and the salt is crystalline.
- If a competitor uses a racemic malate (DL), claim 2 is the tightest dependent hook.
What is the claim boundary for “malate”?
The claims define “malate salt” but do not expressly expand into:
- other malate-derived acids (not applicable)
- cocrystals
- hydrates/solvates unless they are treated as “crystalline malate salt” in the intrinsic disclosure or claim interpretation
Enforcement risk area: products marketed as “malate” with different crystalline forms (polymorphs), solvates, or hydrates can raise literal infringement questions if crystallinity and the salt identity are contested.
Which limitations in the claims are most likely to drive infringement and design-around outcomes?
1) The fixed API backbone is the hardest-to-design-around element
The chemical is fully specified:
- cyclopropane-1,1-dicarboxamide core
- N-substitutions: one is a substituted phenyl ether to a quinoline with 6,7-bis(methyloxy,quinolin-4-yl) substitution; the other is 4-fluorophenyl
- the amide connectivity is fixed by the name
Design-around implication: changing the quinoline substitution pattern, the phenyl substitution pattern, replacing the 4-fluoro phenyl, or altering amide connectivity likely avoids the claimed structure. In contrast, changing the counterion is comparatively easier.
2) “Malate salt” is the second critical fence
Even with the same API, switching to other acids (e.g., fumarate, succinate, citrate, tartrate, sulfate) avoids the literal “malate salt” requirement. If the landscape includes other salt patents, that switch may trigger other barriers.
3) “Crystalline” is a third barrier that can matter in enforcement
Claim 1 requires crystallinity. Practically, salt products often exist as:
- polymorphs
- hydrates
- solvates
- amorphous solids
If a competitor can show its commercial material is amorphous or structurally distinct such that it is not “crystalline malate salt,” claim 1 becomes harder to assert.
4) Enantiopure vs racemic malate matters for dependent claims
Dependent claims tie to DL, L, or D forms. If a competitor uses a different malate stereochemical form than the asserted dependent claim, literal infringement of that dependent claim is blocked, though claim 1 could still be asserted if “malate salt” and crystallinity are met.
What patents protect the same molecule (or close equivalents) in the U.S.?
Scope of protection in the U.S. salt landscape typically clusters into two layers:
- patents on the free base or the core chemical entity (structure and/or composition)
- patents on salt forms, crystal forms, and polymorphs, often including stereochemically defined salts
For US 11,091,439 specifically, the claims indicate it is positioned as a crystalline malate protection layer on top of a broader chemical series. The independent claim is not “method-of-use” and not a general formula claim; it is a strict product definition that likely complements earlier or later patents covering:
- the free base (or broader genus of analogs)
- other salt forms (different counterions)
- other crystal forms/polymorphs of malate
- potentially synthesis intermediates or manufacturing methods (not shown in your excerpt)
Actionable landscape assessment (based only on the provided claim set):
- This patent most directly blocks crystalline malate versions of the stated API.
- It does not block other salts in a purely literal way.
- It does not inherently block amorphous malate unless “crystalline” is satisfied by the commercial solid.
- It does not, by itself, block different stereochemical choices unless they still fall under the relevant malate stereochemistry claims or claim 1’s malate definition plus crystallinity is met.
When does the patent lose exclusivity or expire?
No answer can be produced from the information provided. The expiration timeline requires filing/priority dates, USPTO event data, term adjustments, and any regulatory exclusivity interactions, none of which are included in the prompt.
What is the Orange Book status of US 11,091,439 and which FDA products list it?
No answer can be produced from the information provided. Orange Book status requires the listed drug product, applicant/NDA/ANDA/BLA, and the specific patents listed for that product.
How strong is the patent estate for crystalline malate salts of this API?
Claim strength indicators from the text you provided
- High specificity on chemical identity: reduces ambiguity in what “the invention” is.
- Explicit “crystalline” and stereochemical salt definitions: narrows the scope but supports enforceability when the accused product matches the solid form and stereochemistry.
Main litigation vulnerability indicators
- The claims are narrow; if the commercial form is:
- a different salt
- a different stereochemical malate form than asserted dependent claims
- amorphous or a different non-crystalline form
then infringement theories can narrow or fail.
- Enforcement will hinge on the accused product’s solid-state characterization. Crystallinity and polymorph identification become central.
What formulation patents and solid-state patents typically surround salt-form claims like this?
Even without additional record data, salt-form patents usually co-exist with parallel claims in these categories:
- other pharmaceutically acceptable salts of the same API
- polymorphs or crystalline modifications of the malate salt
- solvates and hydrates
- processes to form the crystalline salt (method claims), including crystallization conditions
- particle size distributions tied to crystal form (sometimes as part of “crystalline” definition or dependent claims)
For US 11,091,439, the claim set you provided suggests:
- if there are other patents, they likely expand across other salt forms or across solid-state derivatives of malate (polymorphs/solvates)
- this patent is a targeted capture of a crystalline malate baseline plus stereochemical acid form
What generic entry risks exist for a company selling this API as a malate?
Within a narrow “salt-form only” frame:
- If an ANDA applicant or generic uses an API with the same structure and files with crystalline malate as the intended solid form, infringement risk is high.
- If the applicant uses:
- a different acid salt (non-malate), literal risk against these claims drops sharply
- an amorphous malate solid, literal risk against “crystalline” is reduced but not eliminated if the product converts or is characterized differently
- a different malate stereochemistry than the asserted dependent claim, claim 1 may still be asserted while dependent claims 2–5 may not
How does this patent compare with other salt claims: DL vs L vs D malate?
Claim mapping
- Claim 2: DL-malate (racemate malate) is specifically claimed.
- Claim 4/5: L-malate and D-malate are specifically claimed.
- Claim 3 collects L/D under the umbrella of claim 1’s core identity plus malate salt, again requiring “crystalline” due to claim 1’s incorporated requirement.
In practical settlement posture
- If the commercial product is enantiopure malate, the patent holder can target the corresponding dependent claim.
- If commercial supply is racemic malate, claim 2 becomes the tightest hook.
Claim-by-claim structure chart for infringement mapping
| Claim |
Required API identity |
Required acid form |
Crystallinity requirement |
Stereochemical malate requirement |
| 1 |
Exact cyclopropane-1,1-dicarboxamide with quinoline ether and 4-fluorophenyl |
Malate salt |
Yes (“crystalline”) |
Not specified (malate salt generally) |
| 2 |
Same as claim 1 |
Malate salt |
Yes |
DL-malate |
| 3 |
Same as claim 1 |
Malate salt |
Yes |
L-malate or D-malate |
| 4 |
Same as claim 1 |
Malate salt |
Yes |
L-malate |
| 5 |
Same as claim 1 |
Malate salt |
Yes |
D-malate |
Key Takeaways
- US 11,091,439 is a narrow crystalline salt patent centered on malate of one fully specified cyclopropane-1,1-dicarboxamide API with a 6,7-bis(methyloxy)quinolin-4-yl ether motif and a 4-fluorophenyl group.
- Claim 1 is the broadest capture: crystalline malate of the exact API.
- Claims 2–5 add stereochemical malate specificity: DL-, L-, or D-malate.
- The principal design-arounds are at the edges: switching away from malate, using a different solid-state form that is not “crystalline,” or using a different stereochemical malate form (which may still leave claim 1 exposure depending on characterization).
- Exclusivity, expiration, Orange Book listings, and litigation/ANDA risk can’t be determined from the provided claim text alone.
FAQs
Which forms are outside the literal scope of US 11,091,439?
Any product that does not use the exact named API or does not use a malate salt, and any product that is not crystalline, falls outside the literal claim scope.
Can a different malate polymorph evade infringement?
Polymorphs can affect whether the accused material is “crystalline” as claimed and whether it matches the claimed crystalline malate definition in claim construction, but the claim text you provided only specifies “crystalline,” not which polymorph.
Does the patent cover amorphous malate?
Claim 1 requires “crystalline,” so amorphous malate is not clearly covered by the literal language provided.
Does DL-malate infringement also trigger L- or D-malate dependent claims?
DL-malate is distinct from L- or D-malate. Dependent claim coverage depends on which stereochemical malate form the accused product uses, while claim 1 may still be asserted if the accused product is a crystalline malate salt of the claimed API.
Are methods of making the salt protected?
Not from the claims you provided. The excerpt is product-only (malate salt composition), not a manufacturing method or a therapeutic method.
References
- US Patent 11,091,439. (Claims as provided in prompt).
