US Patent 9,107,912 (United States) scope and claims analysis for hyperuricemia treatment with concomitant theophylline dosing
US 9,107,912 is a US method-of-treatment patent centered on using 2-[3-cyano-4-(2-methylpropoxy)phenyl]-4-methylthiazole-5-carboxylic acid (a xanthine oxidoreductase inhibitor; the claim set is drafted to manage drug-drug interaction risk) in hyperuricemia patients who are also on concomitant theophylline. The claim scope is narrow but operationally specific: it requires concomitant theophylline dosing within a tight percentage band of a manufacturer’s recommended dose and includes a functional limitation that the urate-lowering agent does not produce theophylline toxicity.
The estate is likely most relevant to any US challenge, licensing, or generic development scenario involving combined therapy of (1) a febuxostat-like/other XO inhibitor small molecule with (2) theophylline in asthma or related disease states. The claim is structured to withstand general “use as an XO inhibitor” arguments by tying the dosing ratio and toxicity outcome to co-administration.
What claims does US 9,107,912 cover for hyperuricemia treated with theophylline concomitant dosing?
Direct answer: The patent claims a method of treating hyperuricemia by administering the XO inhibitor 2-[3-cyano-4-(2-methylpropoxy)phenyl]-4-methylthiazole-5-carboxylic acid (or a salt) while the patient is concomitantly receiving theophylline at a dose expressed as a percentage of the manufacturer’s recommended theophylline dosage, with an explicit constraint that the XO inhibitor does not result in theophylline toxicity.
Claim 1 is the core combination method-of-use
Claim 1 elements (must all be present):
- Indication/population: “a patient suffering from hyperuricemia in need of treatment,” and the patient is also receiving “at least one second disease state.”
- Therapeutic agent: administering 2-[3-cyano-4-(2-methylpropoxy)phenyl]-4-methylthiazole-5-carboxylic acid (or pharmaceutically acceptable salt).
- Concomitant therapy: patient is also receiving theophylline to treat the second disease state.
- Functional safety limitation: administration of the XO inhibitor “does not result in theophylline toxicity.”
- Dosing ratio limitation: theophylline dose is about 90% to about 110% of manufacturer’s recommended theophylline dosage amount in the absence of administration of at least one xanthine oxidoreductase inhibitor.
- Dose context definition: the ratio is computed against a comparator scenario where an XO inhibitor is not present.
This architecture is typical of interaction-management patents: it converts a pharmacology risk (XO inhibition affecting theophylline exposure or metabolism) into a patentable procedural dosing rule and a toxicity outcome.
Dependent claims narrow clinical context
- Claim 2: second disease state is asthma.
- Claim 3: patient also suffers from at least one third disease state where the third disease is gout.
- Claim 4: theophylline dosage is about 95% to about 105%.
- Claim 5: theophylline dosage is about 99% to about 101% (tightest dosing band).
- Claim 6: patient was previously administered theophylline prior to initiating treatment with the XO inhibitor.
Practical implication: literal infringement is most likely when an accused regimen preserves the tight dosing band around manufacturer recommendations and uses concomitant theophylline therapy for asthma (or another theophylline-treated second disease state) during initiation/administration of the XO inhibitor.
How broad are the dosing, toxicity, and disease-state limitations in US 9,107,912?
Direct answer: The claim is not broad across all XO inhibitor uses in hyperuricemia. It is limited by (1) concomitant theophylline therapy, (2) a quantified theophylline dosing ratio band, and (3) a toxicity non-occurrence functional constraint.
1) Dosing band scope (90–110%) sets a measurable infringement boundary
- Claim 1 uses “about 90% to about 110%” of manufacturer’s recommended dosage in the comparator condition without an XO inhibitor.
- Claims 4 and 5 define narrower windows that are easier to map to actual product instructions and prescriber protocols.
Claim-construction risk points (for enforcement and challenge):
- “manufacturer’s recommended theophylline dosage” anchors the ratio. If a product label uses multiple dosing tiers (loading vs maintenance; age/weight adjustments), the comparator must be chosen consistently.
- “about” creates tolerance for slight deviations; precision is key for any generic label carve-out or stewardship language.
2) Toxicity limitation reduces coverage to regimens where no theophylline toxicity occurs
Claim 1 includes: the XO inhibitor administration “does not result in theophylline toxicity to the patient.”
This is a functional limitation tied to an outcome. For infringement, a patentee would seek clinical evidence of the absence of toxicity during combination therapy at the claimed dosing ratio.
Defense angle (generic or licensee):
- Even if drug interactions are plausible, a regimen designed to avoid toxicity might still practice the claim if toxicity does not occur as required. Conversely, if actual toxicity occurs in practice, that may avoid the “does not result” limitation.
3) Disease-state limitation ties theophylline to the second condition
Claim 2 explicitly locks asthma. Claim 1 uses “at least one second disease state,” where theophylline is given “to treat” that condition.
Implication: theophylline for non-asthma indications could still qualify if a court finds it is “to treat” a second disease state in Claim 1. Dependent Claim 2 increases enforceability in asthma cohorts.
What active ingredient and therapeutic class are implicated by the molecule in US 9,107,912?
Direct answer: The compound name in the claims is a small-molecule xanthine oxidoreductase inhibitor (XO inhibitor), used to lower uric acid and treat hyperuricemia and gout, with a combination-theophylline safety/dosing management concept.
Why the class matters for patent landscape:
- XO inhibitors often change purine metabolism pathways and can influence theophylline exposure indirectly (depending on metabolism and transport characteristics).
- The patent’s novelty resides less in “treat hyperuricemia” and more in “treat hyperuricemia with an XO inhibitor while maintaining theophylline dosing within a specific percentage band to avoid toxicity.”
What is the patent estate size and likely related US patents around US 9,107,912?
Direct answer: Without the patent’s publication family context, assignee, and specification disclosures, the full estate size cannot be enumerated from the claim text alone.
What can be inferred from claim structure:
- US 9,107,912 likely sits in a family containing:
- broader method claims for combination therapy with a theophylline dose management framework, and/or
- dependent claims specifying disease states (asthma, gout),
- salt forms and potentially administration timing.
Actionable licensing/litigation posture:
- For any US freedom-to-operate (FTO) around XO inhibitor-theophylline combination dosing, the highest-risk claim exposure is Claim 1 and its tightest bands (Claims 4 and 5), because these are easiest to map to prescribing data and label dosing.
When does US 9,107,912 expire in the US and how does that affect generic entry timing?
Direct answer: Expiration cannot be calculated from the provided information because US patent expiration depends on:
- earliest effective non-provisional filing date,
- term adjustments,
- any terminal disclaimers,
- continuation strategy,
- and whether this is a non-provisional utility patent not subject to PTA effects.
No patent grant date, filing date, or PTA details are provided in the prompt, so a legally useful expiration date cannot be produced.
What Orange Book status would matter for US 9,107,912 and how would it be used in Paragraph IV strategy?
Direct answer: Orange Book listings cannot be determined from the claim text alone because it requires the specific NDA/ANDA references for the XO inhibitor product (and any listed formulation/method patents).
What matters commercially if US 9,107,912 is listed:
- If the XO inhibitor active ingredient is in the Orange Book, a Paragraph IV certification could specifically target the listed method-of-use patent if it is tied to use (theophylline dosing management during hyperuricemia therapy).
- If not listed, enforcement typically relies on non-Orange Book patent theories tied to use claims.
How strong is the claim scope for enforcement against generics or competing XO inhibitors?
Direct answer: The claim set has strong enforceability on regimens that reproduce the combination and dosing ratio, but it is limited by the tight dosing band and the “no theophylline toxicity” outcome requirement.
Strength factors
- Specific drug identity: the XO inhibitor molecule is fully characterized in Claim 1.
- Specific concomitant drug: theophylline is required.
- Specific dosing metric: 90–110% range anchored to manufacturer recommended dosage without an XO inhibitor.
- Toxicity limitation: creates an identifiable clinical benchmark for the patentee.
Weakness factors
- Narrow clinical scenario: not all hyperuricemia patients; only those on theophylline.
- Outcome limitation: toxicity non-occurrence is fact-dependent and can complicate enforcement proof.
- “At least one second disease state” breadth is limited operationally: it depends on why theophylline is being used.
What generic entry risks exist for theophylline-XO inhibitor combination regimens?
Direct answer: The highest risk is for any generic XO inhibitor that is marketed or prescribed for hyperuricemia in patients concurrently taking theophylline, especially if dosing is managed near labeled recommendations (within the 90–110% band).
Label and stewardship implications:
- A generic sponsor can try to design prescribing guidance that intentionally moves patients outside the claimed dosing ratio window, or introduces additional monitoring controls.
- If physicians follow standard labeled dosing and toxicity does not occur, the regimen can match the claim.
Scenario mapping to the claim:
- Patient with asthma taking theophylline.
- Start XO inhibitor for hyperuricemia/gout.
- Maintain theophylline at ~100% of label dosage “in the absence of XO inhibitors.”
- No theophylline toxicity observed.
This is the textbook infringement alignment for Claim 1 and Claims 2/3.
How does US 9,107,912 compare with typical interaction-management patents in theophylline-XO inhibitor space?
Direct answer: It is more actionable than many general “use” claims because it converts a theoretical interaction into quantified dosing windows and a toxicity outcome requirement.
Key differentiation:
- Many interaction patents claim “co-administer with monitoring” without quantified dosing bands.
- Here, the claimed method is anchored to percent-of-label dosing and “does not result in toxicity,” which is more directly tied to prescriber behavior and clinical outcomes.
What technical and evidentiary record would matter for infringement (and for invalidity) around these claims?
Direct answer: Two evidence streams dominate: (1) dosing regimen compliance with the 90–110% bands (and tighter sub-bands) and (2) clinical evidence regarding theophylline toxicity outcomes.
Infringement proof targets
- Patient-level regimen documentation showing:
- theophylline dose as a percentage of manufacturer recommendation,
- concurrent XO inhibitor dosing,
- timing (Claim 6 requires prior theophylline when relevant),
- diagnosis context (asthma and gout if dependent claims are asserted).
Invalidity proof targets
- Obviousness and lack of enablement arguments generally focus on:
- whether dose-range selection (90–110% and tighter) was routine,
- whether the toxicity outcome limitation is supported by the specification,
- whether prior art combination regimens already encompassed similar dosing management.
The claim text alone does not identify the specification support or prior art.
Key takeaways
- US 9,107,912 is a combination-method patent: it claims treating hyperuricemia using a specific XO inhibitor while the patient is on concomitant theophylline.
- The scope is defined by three hard constraints: the exact XO inhibitor identity, theophylline dosing at ~90–110% of label dose (with narrower dependent windows), and a functional limitation that the regimen does not cause theophylline toxicity.
- Dependent claims add asthma (Claim 2), gout (Claim 3), tighter dosing bands (Claims 4–5), and a timing condition that the patient was previously on theophylline (Claim 6).
- Enforcement risk concentrates on prescribing patterns that keep theophylline near labeled dosing during initiation/continuation of the XO inhibitor in patients who have theophylline-responsive disease states, especially asthma.
FAQs
1) Does US 9,107,912 require theophylline to be dosed for asthma specifically?
No. Claim 1 requires theophylline to treat a “second disease state.” Claim 2 specifically limits that second disease state to asthma.
2) Can infringement occur if theophylline dosing is slightly below 90% of the label dose?
Claim 1 requires about 90% to about 110%. A regimen below that window would not literally satisfy the dosing-range limitation.
3) What is the narrowest theophylline dosing window in the claims?
Claim 5 requires about 99% to about 101% of manufacturer recommended theophylline dosage (without an XO inhibitor).
4) Is prior theophylline use required for all claims?
No. Claim 6 adds that element, so it is only required if Claim 6 is asserted.
5) If a prescriber uses an XO inhibitor for gout/hyperuricemia but the patient is not on theophylline, is the claim implicated?
No. Concomitant theophylline administration is a required element of Claim 1.
References
- US Patent No. 9,107,912 (method of treating hyperuricemia with concomitant theophylline dosing while avoiding theophylline toxicity).
