Scope and patent landscape for US Drug Patent 9,346,822: method claims for hysteromyoma via GnRH antagonism
US 9,346,822 is a US patent that claims a method of treating hysteromyoma (uterine fibroids) by antagonizing gonadotropin-releasing hormone (GnRH) through administration of compounds defined by formula (I) with broad substituent ranges. The broad claim strategy is directed to (1) drug class-like structure coverage (R1–R4 and n variability), (2) treatment indication narrowing (hysteromyoma), and (3) fixed exemplified compound coverage (claim 8). The resulting US landscape is best read as composition-adjacent but method-focused protection, with downstream generic and licensing risk depending on how closely any competing GnRH antagonist compound and regimen maps to formula (I) substitutions.
What is US Patent 9,346,822 claiming for hysteromyoma and GnRH antagonists?
Core claim type: method of treatment.
Treatment target: hysteromyoma (uterine fibroids).
Mechanism of action in claim language: “antagonizing gonadotropin-releasing hormone.”
Administration concept: administering an effective amount of a compound defined by formula (I).
Claim 1: the broadest formula and indication scope
Claim 1 covers:
- A method: treating hysteromyoma
- A MOA: GnRH antagonism
- A compound: “the compound represented by formula (I)” (or a salt)
Claim 1 then specifies parameter constraints:
- R1: C1–4 alkyl
- R2: selected from five major branch types, each with its own allowed substituents:
- C1–6 alkyl with substituents including:
- hydroxy
- C1–4 alkoxy
- C1–4 alkoxy-carbonyl
- di-C1–4 alkyl-carbamoyl
- C5–7 member N-heterocycle
- C1–4 alkyl-carbonyl
- halogen
- C3–8 cycloalkyl with optional hydroxy or mono-C1–4 alkyl-carbonylamino
- C5–7 member N-heterocycle with allowed substituents including halogen, hydroxy, C1–4 alkyl, C1–4 alkoxy
- Phenyl with optional substituents including halogen, alkoxy-alkyl, mono-alkyl-carbamoyl-alkyl, alkoxy, mono-alkyl-carbamoyl-alkoxy
- C1–4 alkoxy
- R3: C1–4 alkyl
- R4: one of six categories including:
- hydrogen
- C1–4 alkoxy
- C6–10 aryl
- “N—C1–4 alkyl-N—C1–4 alkylsulfonylamino”
- hydroxyl
- a C5–7 member N-heterocycle with a substituent selected from oxo, C1–4 alkyl, hydroxy-C1–4 alkyl, C1–4 alkoxy-carbonyl, mono-C1–4 alkyl-carbamoyl, C1–4 alkylsulfonyl
- n: integer 1–4
Important built-in conditional restriction:
- “Provided that when R2 is a phenyl which may have a substituent, R4 is a C5–7 member nitrogen-containing heterocyclic group…” with further substituent options.
That conditional is a classic claim-drafting move to keep the scope from becoming internally inconsistent for a subset of structures.
Claim 2: narrower R2 subclass
Claim 2 limits R2 to a 5–7 member N-heterocycle with a specific substituent set:
- halogen
- hydroxy
- C1–4 alkyl
- C1–4 alkoxy
Claim 3: R4 = hydrogen
Claim 3 locks R4 = H.
Claims 4–7: exemplified simplifications
- Claim 4: R1 = methyl
- Claim 5: R3 = methyl
- Claim 6: n = 1
- Claim 7: combination: R3 = methyl, R4 = hydrogen, n = 1
Claim 8: fixed, fully specified compound
Claim 8 directly names the compound:
N-(4-(1-(2,6-difluorobenzyl)-5-((dimethylamino)methyl)-3-(6-methoxy-3-pyridazinyl)-2,4-dioxo-1,2,3,4-tetrahydrothieno[2,3-d]pyrimidin-6-yl)phenyl)-N′-methoxyurea, or a salt thereof.
This claim serves as an anchor point. Even if broader formula coverage is contested, the specifically recited molecule gives the patentee a clean target structure.
How broad is formula (I) coverage under US 9,346,822 for GnRH antagonists?
US 9,346,822’s scope is best understood as structure coverage via enumerated substituent classes rather than open-ended generic language.
What drives breadth
- R1 variability (C1–4 alkyl): methyl/ethyl/propyl/butyl style options.
- R2 variability: five major structural “blocks” (alkyl, cycloalkyl, N-heterocycle, phenyl, alkoxy) each with multiple allowed substituent types.
- R4 variability: includes heterocycle-containing and sulfonylamino variants, plus aryl and hydroxyl.
- n = 1–4: allows ring-size or substituent-position scaling depending on how formula (I) defines n.
What limits breadth
- The conditional linking R2 phenyl → R4 must be a specific N-heterocycle narrows that corner of the chemical space.
- The substituent lists are enumerated; they are not purely “any substituent” language.
- The method claim is tied to hysteromyoma. A GnRH antagonist used for other indications is not within the claim wording.
Design-around pressure points
A designer of around-the-patent compounds would typically attack at least one of:
- moving to an alternative scaffold that does not satisfy formula (I) substitutions
- keeping the scaffold but altering R2 or R4 outside the allowed enumerations
- using a different MOA (if non-GnRH antagonist) or non-hysteromyoma indication patterns (less likely to be practical)
For litigation risk, the most likely factual dispute is whether a competitor’s molecule fits formula (I) definitions (exact structure mapping) and whether the competitor’s product is used to treat hysteromyoma in an infringing way.
Which exact compound is covered by Claim 8, and why does it matter for the estate?
Claim 8 provides an explicit compound identity:
N-(4-(1-(2,6-difluorobenzyl)-5-((dimethylamino)methyl)-3-(6-methoxy-3-pyridazinyl)-2,4-dioxo-1,2,3,4-tetrahydrothieno[2,3-d]pyrimidin-6-yl)phenyl)-N′-methoxyurea (and salts).
Practical litigation implication
When an estate includes both:
- broad genus claims (formula (I)), and
- a narrow species claim (explicit compound),
the patentee can often preserve some infringement theories even if the broad genus claim is challenged as non-encompassing, non-enabling, or not supported as a whole.
Even without knowing the file history, the presence of Claim 8 typically signals the applicant had a concrete lead and wanted at least a fallback protection.
What patent landscape surrounds US 9,346,822: how do related patents usually split coverage?
Without an Orange Book extract, prosecution history, or the patent family list, the landscape around US 9,346,822 can only be described at the level of typical claim-portfolio structure for GnRH antagonists aimed at uterine fibroids.
Common related US patent categories you should expect in the same program
Given the method-of-treatment drafting, the family likely has:
- Composition claims covering the GnRH antagonist core (or close analogs).
- Method claims for specific indications like hysteromyoma/uterine fibroids.
- Formulation claims (dosage forms, controlled release, excipients) tied to dosing.
- Process/manufacturing claims (intermediates, specific steps).
- Salt/polymorph claims if the program pursued solid-state differentiation.
How method claims affect infringement analysis
For method patents, a key question in US litigation is whether:
- the accused product label induces use for the claimed indication, and
- the accused actor (manufacturer, marketer, prescribing physician, patient) performs the claimed treatment method.
This often drives the legal strategy toward:
- label-based inducement theories for Paragraph IV and generic launch disputes, and
- medical-use evidence.
When does US 9,346,822 expire and what exclusivity layers could extend market control?
No expiration date can be computed from the user-provided content alone, because US expiration depends on:
- the patent’s priority date(s),
- filing date(s),
- continuation chain effects,
- and whether any patent term adjustment applies.
Similarly, market exclusivity for the underlying drug (NCE, 505(b)(1), biologic exclusivity, orphan exclusivity if applicable) depends on the FDA approval pathway and date.
Because no priority/filing/adjustment data is included in the prompt, no definitive exclusivity timeline can be produced here.
What generic entry risks exist for hysteromyoma GnRH antagonists under a method-of-use claim like 9,346,822?
Claim-to-risk mapping
A generic entrant faces two principal risk vectors:
- Chemical fit risk: is the generic active ingredient within formula (I) constraints (R1–R4 and n)?
- Indication fit risk: even if chemical fit exists, infringement hinges on use “for treating hysteromyoma” via GnRH antagonism, not off-label uses elsewhere.
Why Claim 8 increases risk
If the commercial reference drug or a close follow-on uses a compound structurally matching Claim 8, the risk of “you are outside formula (I)” defenses decreases. A specifically named species is harder to evade by minor substitutions.
How does US 9,346,822 compare to other GnRH antagonist patent strategies for uterine fibroids?
Versus composition-only claims
- Composition-only claims focus on the molecule regardless of use.
- US 9,346,822 is use-oriented. That can be favorable to generics if they can avoid the claimed indication use, but labeling and inducement theories can still bring exposure.
Versus narrow method claims
Many uterine fibroid patents are narrower (for example, tied to dose ranges, dosing schedules, or specific endpoints). Here, Claim 1 does not specify:
- dose amount,
- dosing frequency,
- duration of treatment,
- or a pharmacodynamic endpoint.
That absence increases practical claim reach, but the genus structure scope still gates infringement.
What do Claims 1–8 imply for licensing leverage and patent settlement posture?
Licensing leverage
The combination of:
- a broad formula genus (Claim 1),
- multiple subset narrowing claims (Claims 2–7), and
- a fully specified species (Claim 8)
creates multiple negotiation anchors. In settlement contexts, parties can trade:
- generic timing concessions tied to certainty around chemical scope (formula mapping),
- versus broader cross-licenses if the parties anticipate that adjacent compounds might be caught.
Potential settlement drivers
- Whether the commercially relevant GnRH antagonist in fibroids is the explicitly named compound from Claim 8.
- Whether the generic’s active ingredient is within formula (I), not merely similar.
Key Takeaways
- US 9,346,822 is a GnRH-antagonist method-of-use patent for hysteromyoma, covering administration of formula (I) compounds with broad R1–R4 and n variability.
- The strongest “anchor” is Claim 8, which fully specifies a single compound: a thieno[2,3-d]pyrimidin dioxo urea derivative with 2,6-difluorobenzyl and a methoxyurea motif.
- Breadth is constrained by enumerated substituent sets and a key conditional restriction when R2 is phenyl.
- Generic risk depends on (i) structural fit to formula (I) and (ii) whether the product is used to treat hysteromyoma consistent with GnRH antagonism.
FAQs
1. What is the main infringement issue for US 9,346,822, structure or indication?
Indication is part of the method claim (“treating hysteromyoma”), but infringement typically turns first on whether the accused active ingredient falls within formula (I) under the R1–R4 and n definitions.
2. Does US 9,346,822 protect off-label uses of a GnRH antagonist for uterine fibroids-related symptoms?
The claim language is tied to “treating hysteromyoma.” Uses that do not constitute treatment of hysteromyoma as such fall outside the method wording.
3. How do Claim 2 and Claims 3–7 change enforcement leverage?
They narrow scope into particular R2 and R4 configurations, creating additional fallback claim paths even if some genus positions are contested.
4. Why does the explicitly named compound in Claim 8 matter more than formula language?
A named species provides a concrete structural match target, making it easier to build infringement arguments around that exact molecule.
5. Can a generic avoid liability by using a different dosing regimen while keeping the same drug?
The claim set provided does not recite dose or schedule limitations in Claims 1–8, so changing regimen alone would not necessarily avoid infringement if the method elements remain satisfied.
References (APA)
- United States Patent No. 9,346,822. Claims as provided in the prompt.
