US Patent 9,499,545: Claim Scope, CGRP Antagonist Coverage, and Patent Landscape
US Patent 9,499,545 is directed to a chemically defined genus of small-molecule migraine treatments, including pharmaceutically acceptable salts, pharmaceutical compositions, and methods of treating migraine. Its principal protection is claim 1, which covers compounds having a specified Formula I scaffold and tightly controlled substituent patterns. Claims 2 and 3 extend protection to compositions and migraine-treatment use.
The claims are consistent with a calcitonin gene-related peptide, or CGRP, receptor antagonist program. The patent does not, from the quoted claims alone, establish coverage of any approved CGRP product such as Nurtec ODT, Ubrelvy, Qulipta, Zavzpret, Aimovig, Ajovy, or Emgality.
What does US Patent 9,499,545 claim?
The patent has three operative claim categories:
| Claim |
Subject matter |
Practical scope |
| 1 |
Formula I compound or pharmaceutically acceptable salt |
Core chemical protection |
| 2 |
Pharmaceutical composition containing claim 1 compound |
Product and formulation protection |
| 3 |
Method of treating migraine by administering claim 1 compound |
Method-of-use protection |
Claim 1 is a Markush claim. It does not claim one compound. It claims a potentially large family of compounds defined by:
- A Formula I molecular scaffold;
- X as a substituted alkene carbon, with R8 equal to hydrogen, fluorine, or cyano;
- R1 as selected alkyl or cycloalkylmethyl substituents;
- R2 as hydrogen or methyl;
- Halogen, methyl, and hydrogen substitution on the R3-R7 positions;
- Multiple exclusion rules controlling permitted substitution patterns;
- Pharmaceutically acceptable salts.
The claim therefore protects both individual compounds falling within the formula and the defined genus as a whole, subject to validity, written-description, enablement, definiteness, and prosecution-history limitations.
How broad is claim 1 of US 9,499,545?
Claim 1 is chemically broad at the genus level but structurally constrained at the substitution level.
R1 substituent scope
R1 may be:
- C1-4 alkyl;
- Cyclopropylmethyl;
- Cyclobutylmethyl; or
- [1-(Trifluoromethyl)cyclopropyl]methyl.
Each R1 group may carry fluorine or hydroxy substituents where valence permits. This gives the claim meaningful coverage over small lipophilic side chains while excluding unrestricted aryl, heteroaryl, longer-chain, and heavily functionalized substituents.
The [1-(trifluoromethyl)cyclopropyl]methyl option is particularly important. It combines a compact cyclopropyl group with a strong electron-withdrawing trifluoromethyl group and may capture optimized pharmacokinetic or receptor-binding variants within the disclosed series.
R2-dependent substitution branches
The claim divides into two principal branches.
R2 equals hydrogen
When R2 is hydrogen:
- R3 may be hydrogen, fluorine, or chlorine;
- R4 may be hydrogen, fluorine, or chlorine;
- R5 must be hydrogen;
- R6 may be hydrogen or fluorine;
- R7 may be hydrogen, fluorine, or chlorine.
The claim requires at least two of R3, R4, R6, and R7 to be fluorine or chlorine, except when R3 is fluorine. If R4 is chlorine, R7 cannot be chlorine.
This branch is designed to preserve a minimum halogenation pattern. The exclusions reduce overlap with less-substituted analogues and avoid certain duplicated chlorine arrangements.
R2 equals methyl
When R2 is methyl:
- R3 may be hydrogen, methyl, fluorine, chlorine, or bromine;
- R4 may be hydrogen, methyl, fluorine, or chlorine;
- R5 may be hydrogen or fluorine;
- R6 may be hydrogen or fluorine;
- R7 may be hydrogen, methyl, fluorine, or chlorine.
If R5 is fluorine, at least three of R3, R4, R6, and R7 must be fluorine. If R4 is methyl or chlorine, R7 cannot be methyl or chlorine.
This branch permits more substitution diversity than the R2-hydrogen branch, including bromine at R3 and methyl substituents at R3, R4, and R7. The exclusions are material because they define the perimeter of the claimed genus and may determine whether a particular development candidate falls inside or outside the claim.
What compounds are likely to infringe claim 1?
A candidate compound is likely to fall within claim 1 only if all required elements are satisfied:
- The compound has the claimed Formula I scaffold.
- X is C(R8)= with R8 equal to H, F, or CN.
- R1 falls within one of the expressly listed groups.
- R2 is either hydrogen or methyl.
- R3-R7 comply with the relevant substitution branch.
- The compound is the claimed free compound or a pharmaceutically acceptable salt.
Literal infringement is therefore highly dependent on exact chemical structure. A molecule with the same therapeutic target but a different core, different R1 group, or non-permitted substitution pattern would not literally infringe claim 1.
A structurally different CGRP antagonist could still present a potential doctrine-of-equivalents issue, but that analysis would depend on prosecution history, prior-art amendments, ensnarement, and the precise structural difference. The quoted claims do not support a reliable doctrine-of-equivalents conclusion.
What does claim 2 protect?
Claim 2 covers a pharmaceutical composition comprising:
- An inert carrier; and
- A compound of claim 1 or its pharmaceutically acceptable salt.
The claim is narrower than a general composition claim because it depends on claim 1. It does not independently cover every formulation containing a CGRP antagonist. The formulation may include conventional dosage-form components such as:
- Tablets or capsules;
- Diluent and binder systems;
- Disintegrants;
- Lubricants;
- Film coatings;
- Oral suspensions;
- Injectable carriers; or
- Nasal or other delivery vehicles.
The term "inert carrier" limits the claim to a composition in which the carrier is pharmacologically inactive relative to the claimed active compound. Claim 2 does not expressly require a particular dosage form, release profile, excipient, particle size, polymorph, solid state, or route of administration.
Does claim 2 cover a commercial formulation?
Only if the active pharmaceutical ingredient falls within claim 1. A formulation patent covering a different active compound, a specific polymorph, a coated tablet, an orally disintegrating tablet, or a particular excipient system would be legally distinct from claim 2, although overlapping protection could exist.
What does claim 3 protect?
Claim 3 covers a method of treating migraine in a mammalian patient by administering a therapeutically effective amount of a claim 1 compound or salt.
The claim requires:
- A mammalian patient;
- A diagnosis or treatment context involving migraine;
- Administration of a qualifying compound;
- A therapeutically effective amount.
The claim is not limited to a specific migraine subtype, dose, dosing interval, route, formulation, or patient population. It may therefore reach treatment of different migraine presentations if the administered compound satisfies claim 1.
It does not expressly cover every indication associated with CGRP antagonism. Treatment of cluster headache, osteoarthritis pain, visceral pain, or another non-migraine condition would not literally satisfy the stated method claim unless the facts also establish migraine treatment.
What are the principal design-around routes?
A generic or competing innovator could seek to avoid literal infringement through several structural strategies:
| Design-around approach |
Claim 1 risk |
| Change the core scaffold |
Usually reduces literal infringement risk |
| Replace R1 with a non-listed group |
Strong potential design-around |
| Use R2 other than hydrogen or methyl |
Strong potential design-around |
| Alter the R3-R7 substitution pattern |
Potentially effective if outside all branches |
| Replace the claimed alkene arrangement |
Potentially effective |
| Use a non-covered salt or prodrug |
Requires separate analysis |
| Retain structure but use a non-migraine indication |
May avoid claim 3, but not claims 1 or 2 |
The most direct design-around strategy is changing R1 or the Formula I core. Modifying only one halogen can be sufficient, but the result must be tested against every alternative in the Markush language and any relevant dependent claims not quoted by the user.
What patent landscape surrounds this patent?
The relevant landscape is the small-molecule CGRP antagonist field. It includes several separate patent layers:
Core composition patents
These cover the chemical scaffold and specific compounds. They are generally the strongest barriers because they can block manufacture, sale, and importation regardless of the approved indication.
Salt, polymorph, and solid-state patents
These may cover:
- Specific crystalline forms;
- Amorphous forms;
- Hydrates or solvates;
- Pharmaceutically acceptable salts;
- Particle-size distributions;
- Stability-enhancing forms.
The quoted claim 1 expressly includes pharmaceutically acceptable salts, but it does not identify a particular salt, crystal form, or solid-state property.
Formulation patents
Formulation patents can cover:
- Orally disintegrating tablets;
- Rapid-dissolution formulations;
- Low-dose tablets;
- Extended-release products;
- Nasal delivery systems;
- Injectable formulations;
- Specific excipient combinations.
Claim 2 is not a detailed formulation claim. It lacks a defined dosage form and does not recite particular excipients or performance parameters.
Method-of-use patents
Method patents may cover:
- Acute migraine treatment;
- Migraine prevention;
- Treatment with or without aura;
- Reduction of monthly migraine days;
- Dosing after symptom onset;
- Specific dosing regimens;
- Use in patients with cardiovascular contraindications to triptans.
Claim 3 is comparatively broad because it recites migraine treatment without a detailed dosing regimen or patient subgroup.
Manufacturing and process patents
Manufacturing patents may protect:
- Key intermediates;
- Chiral resolution;
- Catalytic coupling steps;
- Crystallization procedures;
- Salt formation;
- Purification;
- Process-specific impurity control.
Even if a competitor designs around claim 1, process patents can create separate manufacturing and supply-chain barriers.
Is US 9,499,545 listed in the Orange Book?
An Orange Book listing is product-specific, not patent-number-specific. The FDA lists patents submitted by an NDA holder for a particular approved drug product, dosage form, or method of use. A patent directed to an investigational compound or an unapproved compound is not independently listed merely because it claims migraine treatment (FDA, 2024a).
The quoted claims do not identify an approved product, NDA number, trade name, or active ingredient. The claims alone therefore do not establish Orange Book listing status.
For a marketed CGRP antagonist, the relevant inquiry is whether the NDA holder submitted this patent for the approved product and whether FDA accepted the patent as a listed drug patent. A patent can be technically relevant to a product yet absent from the Orange Book.
When would a Paragraph IV challenge matter?
A Paragraph IV certification becomes relevant only if:
- The patent is listed in the Orange Book for the reference drug;
- A generic applicant files an ANDA referencing that drug; and
- The generic applicant certifies that the patent is invalid, unenforceable, or will not be infringed.
The generic applicant must notify the patent owner and NDA holder. A timely infringement action can trigger a 30-month stay of FDA approval under the Hatch-Waxman framework (21 U.S.C. § 355(j)(2)(A)(vii); 21 C.F.R. § 314.107).
For a compound claim such as claim 1, a Paragraph IV case would likely focus on:
- Anticipation by an earlier compound patent;
- Obviousness over CGRP antagonist prior art;
- Written description of the full Markush genus;
- Enablement across the claimed substitution space;
- Definiteness of the structural limitations;
- Prosecution-history estoppel;
- Whether the listed patent actually covers the generic product.
A generic that uses a different active compound would generally not face claim 1 merely because it treats the same disease.
What is the biosimilar risk?
Biosimilar risk is not the principal issue for this patent. Claims 1-3 cover small molecules, not biologic products. Generic-drug pathways under section 505(j), rather than biosimilar applications under section 351(k), would ordinarily apply to a covered small-molecule product.
The major commercial risk is therefore small-molecule generic entry, not biosimilar substitution. Separate biosimilar competition affects injectable monoclonal-antibody CGRP products such as erenumab, fremanezumab, and galcanezumab, but those products do not fall within the quoted compound claims.
How strong is the patent estate based on the quoted claims?
The claim set has a mixed strength profile:
| Factor |
Assessment |
| Core chemical claim |
Potentially strong if the Formula I scaffold is novel and enabled |
| Genus breadth |
Moderate to broad, but vulnerable to written-description and enablement attacks |
| R1 coverage |
Meaningful but limited to specified small substituents |
| Substitution controls |
Narrow the genus and improve definiteness |
| Composition claim |
Broad but dependent and relatively conventional |
| Migraine method claim |
Broad indication coverage, but dependent on the compound claim |
| Formulation protection |
Weak from the quoted claims alone |
| Manufacturing protection |
Not shown in the quoted claims |
| Product-specific Orange Book value |
Cannot be established from the claims alone |
The strongest commercial feature is claim 1's ability to block manufacture and sale of covered compounds independent of whether a competitor uses the same brand, formulation, or dosing schedule. The main vulnerability is that the claim covers a genus defined by numerous substituent permutations. The patent's durability depends on the specification's examples, assay data, synthetic disclosure, priority chain, and prosecution record.
How does this patent compare with marketed CGRP products?
| Product |
Modality |
Relationship to quoted claims |
| Nurtec ODT, rimegepant |
Small-molecule CGRP antagonist |
Requires exact structural comparison |
| Ubrelvy, ubrogepant |
Small-molecule CGRP antagonist |
Target similarity does not establish claim coverage |
| Qulipta, atogepant |
Small-molecule CGRP antagonist |
Requires exact Formula I analysis |
| Zavzpret, zavegepant |
Small-molecule CGRP antagonist |
Requires exact Formula I analysis |
| Aimovig, erenumab |
Monoclonal antibody |
Outside the quoted small-molecule claims |
| Ajovy, fremanezumab |
Monoclonal antibody |
Outside the quoted small-molecule claims |
| Emgality, galcanezumab |
Monoclonal antibody |
Outside the quoted small-molecule claims |
CGRP receptor antagonism is not enough to establish infringement. The active ingredient must satisfy the claimed molecular architecture and substitution rules.
Key Takeaways
- Claim 1 is the primary commercial claim and covers a defined Formula I genus of small-molecule migraine compounds and pharmaceutically acceptable salts.
- R1 is limited to short alkyl and selected cycloalkylmethyl groups.
- R2 creates separate hydrogen and methyl substitution branches with different halogen, methyl, and exclusion requirements.
- Claim 2 covers compositions containing a claim 1 compound but does not provide detailed formulation, dosage-form, polymorph, or excipient protection.
- Claim 3 covers administration of a claim 1 compound for migraine treatment without a specified dose or route.
- The patent is relevant to the small-molecule CGRP antagonist landscape, but target or therapeutic similarity does not establish infringement.
- Orange Book status cannot be inferred from the patent claims. Listing depends on an NDA holder's submission for a specific approved product.
- Paragraph IV litigation would matter only if the patent is Orange Book-listed for the reference product used by an ANDA applicant.
- Biosimilar risk is generally irrelevant because the claims cover small molecules rather than biologics.
- Patent strength depends heavily on the specification, examples, priority chain, prosecution history, and any unquoted claims.
FAQs
Does US 9,499,545 claim a specific migraine drug?
The quoted claims do not identify a trade-name drug or a single active ingredient. They claim a Formula I genus and compounds within that genus.
Can a generic avoid US 9,499,545 by changing the dosage?
Changing dose or dosing frequency would not avoid claims 1 or 2. It may affect claim 3 only if the treatment no longer satisfies its limitations.
Does a different CGRP antagonist infringe this patent?
Not automatically. A different CGRP antagonist would need to be compared element by element against Formula I and the R1-R7 limitations.
Does claim 2 cover an orally disintegrating tablet?
It may cover such a tablet if it contains a claim 1 compound and an inert carrier. The claim does not expressly require an orally disintegrating dosage form.
Can the patent block manufacture outside the United States?
US patent claims generally create risk for making, using, selling, offering to sell, or importing the claimed invention into the United States. Foreign manufacturing creates US risk principally when the product is imported or otherwise connected to conduct covered by US patent law.
References
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Food and Drug Administration. (2024a). Approved drug products with therapeutic equivalence evaluations. U.S. Department of Health and Human Services.
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Food and Drug Administration. (2024b). Purple Book: Database of licensed biological products. U.S. Department of Health and Human Services.
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U.S. Code. (2024). 21 U.S.C. § 355: New drugs.
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U.S. Patent No. 9,499,545. (2016). Compound, pharmaceutical composition, and method of treating migraine. United States Patent and Trademark Office.
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U.S. Patent and Trademark Office. (2024). Patent term adjustment and patent term calculation. U.S. Department of Commerce.
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Code of Federal Regulations. (2024). 21 C.F.R. § 314.107: Effective date of approval of an abbreviated new drug application.
