US Patent 11,963,971 scope and claims analysis: oral cedazuridine/decitabine dose that matches IV decitabine exposure and pharmacodynamics
Executive summary
- US 11,963,971 claims a solid oral dosage form containing cedazuridine (100 mg) + decitabine (35 mg) and excipients (including lactose monohydrate, HPMC, croscarmellose sodium, colloidal silicon dioxide, magnesium stearate), optionally with a coating. The core limitation is exposure equivalence: after daily administration, the 5-day AUC for decitabine is equivalent to the 5-day AUC from daily IV decitabine 20 mg/m² (1-hour infusion).
- Dependent claim coverage tightens the PK shape (AUC day 2 vs day 1 ratio), and extends to pharmacodynamic equivalence (DNA demethylation).
- The patent’s claim structure is built around systemic exposure and PD readouts rather than just composition or unit size, which increases enforcement leverage against generics that attempt “same dose” replication but do not match the specified multi-day PK/PD equivalence.
- Patent landscape risk for competitors is driven by whether their oral cedazuridine/decitabine products achieve the same AUC equivalence and DNA demethylation PD equivalence under comparable regimens, and whether other patents in the estate already cover formulation details, coating selections, or regimen-specific equivalence methods.
What is US 11,963,971 claiming, and how broad is the “AUC equivalence” limitation?
Answer (scope in one line): It claims an oral cedazuridine/decitabine solid dosage with defined components plus a measurable PK equivalence benchmark tying 5-day decitabine exposure to daily IV decitabine 20 mg/m² (1 h infusion).
Core independent claim 1: composition + optional coating + PK equivalence benchmark
Claim 1 has three gating elements:
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Dosage form type
- “solid oral dosage form consisting of” specified actives and excipients.
- The “consisting of” language is typically a closed transition: it constrains the formulation to the listed components (subject to the claim’s “optionally a coating” carveout and any permitted impurities, processing aids, or intrinsic coating components depending on construction).
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Quantified formulation
- Cedazuridine: 100 mg
- Decitabine: 35 mg
- Excipients listed:
- lactose monohydrate
- hydroxypropyl methyl cellulose
- croscarmellose sodium
- colloidal silicon dioxide
- magnesium stearate
-
Optional coating
- Coating is permitted: “optionally a coating.”
- This preserves infringement pathways for coated embodiments while not requiring a coating for all covered products.
-
PK equivalence under a defined dosing regimen
- The key functional limitation:
- “upon daily administration to a human provides plasma levels of decitabine with a 5-day AUC for decitabine that is equivalent to the 5-day AUC for a daily intravenous dose of decitabine of 20 mg/m² administered as a 1 h infusion.”
- This imports a comparative pharmacokinetic standard anchored to IV exposure rather than a standalone plasma target.
- It also makes the claim regimen-dependent (daily dosing for 5 days with a measured 5-day AUC).
Practical breadth impact
- A competitor cannot avoid claim scope simply by using the same actives in a different ratio, because the actives are quantified at 100 mg cedazuridine / 35 mg decitabine and the excipient list is locked.
- A competitor cannot avoid on “different PK end point” because the claim is expressly pegged to 5-day decitabine AUC equivalence.
- A competitor can potentially design around by:
- altering excipients (if “consisting of” is construed strictly),
- changing unit strength (different mg per tablet/capsule),
- or producing a PK profile that fails the claimed equivalence standard.
How “equivalent” is used to expand/enforce beyond exact matching
“Equivalent” is a functional target that typically allows tolerance rather than exact numerical equality, which can help a patentee enforce against products that achieve “substantially equivalent” AUC under the claim’s regimen. But enforcement still depends on:
- what measure is used for equivalence (commonly bioequivalence-style bounds or statistical criteria),
- the dosing and sampling schedule,
- and how courts construe “equivalent” in the claim context.
Because claim 1 relies on “5-day AUC” and not just single-dose exposure, the equivalence standard can be harder for challengers to match across repeated dosing.
What additional limitations do dependent claims 2-4 add to narrow infringement coverage?
Answer: Claims 2-4 narrow claim 1’s coverage by adding (i) a day-to-day AUC ratio and (ii) pharmacodynamic equivalence tied to DNA demethylation.
Claim 2: day 2 vs day 1 AUC ratio for decitabine
- Adds: “the ratio of AUC for decitabine on day 2 versus day 1 is about 1.5:1 to about 2:1.”
- This is a shape limitation: two products with similar 5-day AUC could still fall outside the required day 2/day 1 ratio.
- It is a strong enforcement hook if accused products match overall exposure but differ in accumulation kinetics, bioavailability dynamics, or metabolic/inhibition effects.
Claim 3: pharmacodynamic equivalence to IV decitabine
- Adds: “provides a pharmacodynamic effect that is equivalent” to IV decitabine 20 mg/m² (1 h infusion).
- This ties the claim to a functional PD outcome rather than only PK.
- It also increases the evidentiary burden for enforcement: PD readout data are usually needed, but it improves defense complexity for generics.
Claim 4: DNA demethylation is the PD endpoint
- Specifies the PD effect:
- “wherein the pharmacodynamic effect is DNA demethylation.”
- DNA demethylation readouts (global methylation, locus-specific demethylation, or surrogate marks) must align with the claim’s PD definition as construed.
- This can be used as a second axis of infringement: even if the accused product hits the PK equivalence, failure to generate equivalent DNA demethylation under comparable dosing could avoid infringement.
Do claims 5-9 create separate product-shape or coating-specific protection?
Answer: Yes. Claims 5-9 add unit form and coating specificity, which can create separate infringement “lanes” for tablets vs capsules and for particular coatings.
Claim 5: tablet
- “solid oral dosage form… which is a tablet.”
Claim 6: capsule
- “solid oral dosage form… which is a capsule.”
- Claims 5 and 6 are alternatives. Together they cover both common oral unit dosages.
Claim 7-9: coating details, including a named coating brand
- Claim 7: “comprises the coating.”
- Claim 8: coating is a color coating.
- Claim 9: coating is Opadry II 85F15458 Red.
Scope implications
- Claim 9 is a narrow coating species claim. It targets products using that specific coating composition/grade as marketed.
- If a competitor uses a different red color coat, Claim 9 may not read on it, but Claims 7-8 can still cover “coated” and “color-coated” embodiments if those are construed broadly enough and if the rest of claim 1 (composition + PK equivalence) is met.
- The “consisting of” language in claim 1 can interact with coating coverage: coating components may or may not be seen as excluded depending on claim construction. The optional coating provision suggests coating is allowed without breaking the “consisting of” restriction, but the base excipient list remains fixed.
How does the claim language map to an oral cedazuridine/decitabine commercial profile?
Answer: It aligns tightly with an oral regimen where cedazuridine acts as an absorption/enzymatic protection component for decitabine, and the key objective is to reach an IV-equivalent decitabine exposure over multi-day dosing.
Dose anchoring: oral exposure equivalent to IV 20 mg/m² (1-hour infusion)
- IV comparator in claim 1: decitabine 20 mg/m², 1-hour infusion, daily, evaluated on a 5-day AUC basis.
- Oral actives: cedazuridine 100 mg + decitabine 35 mg (per solid dosage unit).
Even without external context, the claim’s PK comparator is explicit, so the covered product is not merely “decitabine-containing.” It is the specific oral combination engineered to replicate IV exposure across the first treatment days.
PD anchoring: DNA demethylation
- The inclusion of DNA demethylation indicates the claimed oral product is designed to elicit the expected pharmacologic activity of decitabine, measured as demethylation.
What is the likely patent landscape coverage strategy around US 11,963,971?
Answer: The claim is designed to sit at the center of an estate that typically includes: formulation specifics, PK/PD matching, and regimen/method-of-use or equivalence claims.
1) Formulation and excipient-specific patents
US 11,963,971 is already excipient-anchored via “consisting of” and quantified amounts. Expect overlapping or adjacent coverage in the family (or other filings) on:
- formulation composition,
- dissolution/disintegration performance,
- tablet or capsule manufacturing,
- coating compositions or specifications.
2) PK equivalence and regimen-specific claims
The “5-day AUC equivalence” plus the “day 2/day 1 ratio” create a niche:
- these are not ordinary chemistry claims,
- they are performance claims based on clinical PK/PD results.
This structure often results from:
- selection of exposure and timepoints where oral delivery behavior is distinctive,
- selection of comparator IV regimens tied to known clinical dosing.
3) PD endpoint specific patents
Claim 4’s DNA demethylation is a targeted PD anchor. Estates commonly include additional PD or biomarker-specific claims for:
- global vs locus-specific demethylation,
- time windows,
- and sample types.
4) Coating-specific claims
Claims 7-9 can appear when the product is developed with a particular coating system. Even if coating changes in later manufacturing revisions, estates may still retain original coating claims.
What generic entry risks exist for products attempting to replicate oral cedazuridine/decitabine exposure?
Answer: The risk is driven by whether a generic (or authorized product) matches both:
- the composition constraints (mg per unit and excipient list), and
- the multi-day PK/PD equivalence benchmarks (5-day AUC equivalence and DNA demethylation equivalence).
Potential design-around approaches
- Composition change: replace lactose monohydrate, modify HPMC type/grade, change disintegrant, alter glidant/silicon dioxide form, or use a different lubricant system. “Consisting of” makes this potentially high-impact.
- Strength/unit change: deviate from 100 mg/35 mg per unit.
- Coating change: avoid Opadry II 85F15458 Red; still vulnerable under broader coated/color coated claims unless design avoids those too.
- PK/PD mismatch: target a different AUC profile that fails:
- “5-day AUC equivalent” standard, or
- “day 2/day 1 ratio ~1.5-2,” or
- DNA demethylation equivalence.
Because the claim is explicitly anchored to PK and PD comparators, generics face clinical and analytical pressure to prove non-infringement through exposure and biomarker data.
How strong is the patent estate for enforcing against oral cedazuridine/decitabine copy products?
Answer: Strong on performance and evidentiary leverage because claim 1 and dependent claims tie infringement to measurable endpoints that are difficult to “paper design around.”
Claim strength drivers
- Closed formulation language (“consisting of”) limits substitution latitude.
- Dual endpoint anchoring (PK equivalence and DNA demethylation PD equivalence) creates multiple potential infringement/defense axes.
- Regimen anchoring (daily, 5-day AUC) is more specific than generic “steady-state AUC” language.
Claim vulnerability drivers
- “Equivalent” and “about” can introduce construction disputes and evidentiary arguments about equivalence thresholds and tolerances.
- If prior art or earlier filings establish similar performance targets, the estate’s enforceability would depend on novelty and non-obviousness for the claimed equivalence and exact formulation.
Key takeaways
- US 11,963,971 claims an oral solid with 100 mg cedazuridine + 35 mg decitabine and a fixed excipient set, optionally coated, where 5-day decitabine AUC after daily administration is equivalent to daily IV decitabine 20 mg/m² (1 h infusion).
- Dependent claims tighten coverage via a required day 2/day 1 AUC ratio (~1.5:1 to ~2:1) and via DNA demethylation as the PD equivalence endpoint.
- Additional dependent claims cover tablet vs capsule forms and provide coating specificity, including Opadry II 85F15458 Red.
- For competitors, the main infringement barrier is not only matching composition, but matching multi-day PK equivalence and DNA demethylation PD under comparable dosing.
FAQs
1) Does US 11,963,971 cover uncoated tablets if the coating is omitted?
Yes. Claim 1 allows an “optional coating,” so uncoated embodiments can still fall within claim scope if other limitations are met.
2) Is the claim limited to a single sampling window or any 5-day AUC definition?
The claim anchors infringement to a “5-day AUC” measured after daily administration, but the exact sampling schedule and how “5-day AUC” is calculated will be critical in any equivalence analysis.
3) Can a product avoid infringement by changing the day 2/day 1 AUC ratio while matching overall 5-day AUC?
Yes. Claim 2 adds a specific day-to-day ratio range that could create a non-infringement path if not met.
4) If an accused product matches PK equivalence, can it still avoid infringement by failing DNA demethylation equivalence?
Yes. Dependent claim 4 requires PD equivalence to DNA demethylation, creating an additional defense axis if the endpoint is not equivalent.
5) Does Opadry II 85F15458 Red matter for infringement if the product uses a different color coating?
Only for claim 9 specifically. Other coated/color-coated claims may still apply depending on construction, but claim 9 is limited to that named coating.
References
No sources were provided for US Patent 11,963,971 text, prosecution history, legal status, or related family members.
