United States Patent 8,283,369 (Gout Treatment) Claim Scope, Coverage Map, and US Patent Landscape
Executive summary: US Drug Patent 8,283,369 claims methods of treating gout in humans using specific small-molecule compounds defined by formulas (III) and (IV) (with enumerated substituent options), including oral dosing, pharmaceutical compositions (tablets/capsules with specified excipient types), salt forms, and combination regimens with common gout actives (allopurinol, febuxostat, FYX-051 and URAT/xanthine oxidase pathway agents). The claim set is method-of-treatment anchored but broad enough to cover any administration of the claimed formula compounds and formulation implementations falling within the excipient/product-type limitations. Competitive entry risk in the US concentrates on whether an accused gout product uses the same (or equivalently substituted) formula (III)/(IV) scaffold, and secondarily on whether it replicates the specified oral tablet/capsule excipient packaging choices and salt selection, since those features are expressly claimed.
What does US Patent 8,283,369 claim for gout methods of treatment?
Direct answer: The patent claims two parallel method claim families: (1) a gout treatment method using a compound of formula (III) and (2) a gout treatment method using a compound of formula (IV). Dependent claims narrow to sulfide vs oxygen, specific halogen substituents, H substituents at R3/R3′, specific salt classes, oral administration, tablets/capsules and certain excipient types, and combination therapy with specified gout pathway agents.
Core independent claim structure (high-level)
Claim 1 (formula III scaffold, gout method):
- Treats gout in a human by administering a compound of formula (III) with defined substituent ranges:
- X = N
- W = S or O
- R1 ∈ {Cl, Br, I, optionally substituted methyl, CF3, CHF2, CH2F}
- R2 includes a carbon-carbon double bond motif (as shown in the formula placeholder)
- RP = cyclopropyl
- R3 and R3′ ∈ {H, lower alkyl}
- R8, R9, R10 = H or pharmaceutically acceptable salt/ester/tautomer
Claim 25 (formula IV scaffold, gout method):
- Administers a compound of formula (IV) (structure not fully restated in your prompt beyond the formula label), to treat gout.
Claim 26 (therapeutic benefit method, formula III scaffold):
- Same compound definition as claim 1, but framed as achieving a therapeutic benefit.
Claim 50 (therapeutic benefit method, formula IV scaffold):
- Same as claim 25 in the “therapeutic benefit” phrasing.
“Branch points” that create actionable scope
The most legally important claim switches are:
- Which scaffold is used: formula (III) vs formula (IV).
- W polarity center: W = S or O (claim 2 and claim 27 narrow to S).
- R1 specific halogen substitution: claim 5 and claim 30 lock R1 = Br.
- A minimal substituent variant at R3/R3′: claim 3/4 and claim 28/29 lock R3 = H and R3′ = H.
- Salt strategy: claim 8/9 and claim 33/34 cover a broad list, with sodium salt singled out.
- Dose form: claim 10 (oral), claim 12–20 (tablets, coated tablets, and specific excipient examples), and claim 37–46 (tablet/capsule with excipient classes).
- Combination therapy: claim 21–24 and claim 46–49 specify add-on actives and examples.
How broad is US 8,283,369 claim coverage across substituents and salt forms?
Substituent coverage (formula III claims 1/26 and dependents)
Freedom-to-operate hinge: a product must either (a) practice a method using a compound falling within the formula (III) parameterization or (b) practice a method using formula (IV).
Claimed substituent ranges explicitly include:
- Halogens: Cl, Br, I (R1)
- Small organics: optionally substituted methyl
- Fluorinated groups: CF3, CHF2, CH2F
- H vs lower alkyl: R3 and R3′ ∈ {H, lower alkyl}
- Polarity switch: W = S or O
- Core ring: cyclopropyl (RP)
- Terminal substitution: R8, R9, R10 = H or salts/esters/tautomers
Most narrow gating examples that still matter in practice:
- R1 = Br (claims 5 and 6; 30 and 31)
- W = S (claims 2/4/27/29)
- R3 = H and R3′ = H (claims 3/4/28/29)
A litigant would generally target these narrower dependents if the accused product is clearly one of the enumerated variants.
Salt/ester/tautomer strategy (claims 8–9 and 33–34)
Claim 8/33 covers pharmaceutically acceptable salts including:
- ammonium; primary/secondary/tertiary amines; lithium; sodium; potassium; calcium; magnesium; aluminum.
Claim 9/34 further narrows to sodium salts.
Practical implication: If a commercial gout drug uses a sodium salt form of a compound that matches formula (III)/(IV), the method claim language is positioned to capture both:
- method of treating gout by administering the salt, and
- method of achieving therapeutic benefit by administering the salt.
What formulation and excipient limitations are claimed in US 8,283,369?
Direct answer: The patent includes dependent claims that narrow the method to administration of the active in pharmaceutical compositions that are tablets or capsules, with dependent claims further specifying coated tablets and example excipient categories: lactose, microcrystalline cellulose, sodium croscarmellose, gelatin, magnesium stearate, and hydroxypropylcellulose or hydroxypropylmethylcellulose.
Tablet and capsule claim hooks
From your claim text:
- Claim 11/36: compound in a pharmaceutical composition with carrier/excipient/diluent.
- Claim 12/37: composition is tablet or capsule.
- Claim 13–20 (tablet-specific):
- Claim 14: coated tablet
- Claim 15: tablet comprises lactose
- Claim 17: tablet comprises sodium croscarmellose
- Claim 19: tablet comprises magnesium stearate
- Claim 20: tablet comprises hydroxypropylcellulose or hydroxypropylmethyl-cellulose
- Claim 18: tablet or capsule comprises gelatin (note the dependent language spans tablet or capsule; it still creates excipient-specific coverage)
- Claim 43/45: tablet or capsule comprises gelatin
Practical claim scope point: These are dependent limitations. A non-lactose tablet could still infringe broader method claims if the method is practiced with the claimed compound, but it would evade the specific excipient-dependent dependents (claims 14–20 and 40–46 clusters).
When does US 8,283,369 expire and how does exclusivity typically run for method-of-use patents?
Direct answer: Your prompt does not include filing date, priority date, patent term adjustment, patent term extension, or any terminal disclaimer details. Without those, an accurate expiration timeline cannot be produced from the claim text alone.
What combination therapy coverage exists in US 8,283,369?
Direct answer: The patent claims add-on use with specified gout pathway agents including URAT 1 inhibitors and xanthine oxidase pathway inhibitors, with examples: allopurinol, febuxostat, FYX-051. The combination is claimed as “further comprising administering a second agent” effective for gout.
Combination dependents (claims 21–24 and 46–49)
- Claim 21/46: further administer a second effective gout agent.
- Claim 22/47: second agent is:
- URAT 1 inhibitor, and/or
- xanthine oxidase inhibitor, and/or
- xanthine dehydrogenase / xanthine oxidoreductase inhibitor, and/or
- combinations.
- Claim 23/48: second agent is allopurinol, febuxostat, FYX-051 (or combination).
- Claim 24/49: second agent is allopurinol.
Practical implications for infringement theory:
- The claim does not require a co-formulation; it requires separate administration as “further comprising administering.”
- If a branded product uses the patented formula compound plus one of the listed actives (even in standard-of-care combinations), this provides a clean “combination regimen” path for method infringement arguments.
How does US 8,283,369 compare with adjacent gout IP patterns (URAT/xanthine oxidase inhibitors)?
Direct answer: The patent is not directed to allopurinol or febuxostat per se. It is directed to a specific new compound scaffold (formula III/IV) for gout treatment methods. It also contains combination regimen coverage that uses known actives as the “second agent.”
Positioning in the gout landscape
In market practice:
- Allopurinol/febuxostat are established xanthine oxidase pathway inhibitors.
- URAT1 inhibitors target urate reabsorption.
- This patent’s novelty is anchored to the formula (III)/(IV) compound, while combination coverage plugs into how those therapies are co-used clinically.
Key analytic outcome: In licensing or freedom-to-operate work, the presence of the “second agent” dependents mainly expands claim coverage against combination regimens, not against monotherapy of established comparators.
What other US patents likely cover the same compound series?
Critical constraint: Your prompt provides only the claim text for US 8,283,369 and does not provide:
- the compound’s chemical name,
- the assignee,
- the application/publication number,
- listed references,
- related family members (continuations/divisionals),
- or the Orange Book listing.
Without those, no complete and accurate “likely other US patents” map can be produced.
What does the claim set imply about infringement risk for generics or alternative formulations?
Direct answer: In a US method-of-treatment context, infringement risk primarily depends on whether a generic (or alternative product) administers a compound that falls within formula (III) or (IV) and practices the gout treatment method. Dependent claim coverage for tablets/capsules with specified excipients creates additional but narrower infringement pathways tied to formulation specifics.
Generic entry risk scenarios
- Product uses a non-infringing compound variant (outside formula III/IV): lowers risk for all dependents.
- Product uses a formula III/IV compound but avoids the specific excipient-dependent dependents (e.g., not lactose, not sodium croscarmellose): still may risk the broader composition-independent method claims (claims 1/10/11/21 etc.), but evades excipient-specific dependents.
- Product uses formula III/IV compound and uses sodium salt form: raises exposure under salt dependents.
- Product co-administers a listed second agent (allopurinol/febuxostat/FYX-051): raises exposure for combination dependents.
What is the Orange Book status of US 8,283,369 and which FDA-listed drugs map to it?
Critical constraint: Orange Book status requires drug/NDA information and the Orange Book patent listing record. Your prompt does not provide NDA/ANDA numbers, listed drug names, or patent listing linkage. A complete and accurate Orange Book mapping cannot be produced.
Key Takeaways
- US 8,283,369 is a method-of-treatment patent for gout centered on a specific compound series defined by formulas (III) and (IV).
- The claim set is broad at the scaffold level (enumerated substituent options for R1, R3/R3′, W, core ring, and hydrogen terminal constraints) and broad at the method-of-use level (treating gout in humans, with oral administration and compositions).
- The patent adds practical narrowing dependents: W = S, R1 = Br, R3/R3′ = H, specific salt classes including sodium, and tablet excipient examples (lactose, microcrystalline cellulose, sodium croscarmellose, magnesium stearate, hydroxypropylcellulose/hydroxypropylmethylcellulose, gelatin).
- The patent expands exposure against combination regimens by explicitly claiming “further comprising” second-agent use with URAT1/xanthine oxidase pathway inhibitors, including allopurinol, febuxostat, FYX-051.
- A defensible US landscape (expiration dates, related patents, Orange Book mapping, litigation outcomes) cannot be completed from the claim text alone.
FAQs
- Does US 8,283,369 require simultaneous dosing with the second gout agent?
- If a product matches formula (III) but uses a non-sodium salt, which dependents remain relevant?
- Can a non-lactose tablet still infringe the tablet/excipient-dependent claims?
- How do W = S vs W = O differences affect claim coverage for formula (III) variants?
- What is the key claim element that most directly distinguishes formula (III) vs formula (IV) infringement theories?
References
- United States Patent No. 8,283,369.
