US Patent 12,433,890: lurbinectedin dose-reduction, timing, and re-escalation regimen for metastatic SCLC post-platinum progression
Executive summary
US Patent 12,433,890 is a method-of-treatment patent for metastatic small cell lung cancer (SCLC) after platinum-based chemotherapy progression, centered on a specific dose/timing and patient hematology recovery-driven re-dosing logic for lurbinectedin monotherapy. The claim set is dominated by:
- a 3.2 mg/m² IV dose followed by re-dosing within 35 days when ANC ≥ 1,500 cells/mm³ and platelets ≥ 100,000/mm³, after Grade 4 neutropenia or febrile neutropenia from the prior dose; and
- optional step-down to 2.6 mg/m² or 2.0 mg/m² using the same hematology thresholds, with constraints on treatment cycle length (21–35 days) and number of cycles (2–24, 3–24, 4–24, 2.6 mg/m² for ≥4/6/10 cycles; 2.0 mg/m² for ≥4/6/10 cycles); plus
- response-duration thresholds tied to the chemotherapy-free interval (<90 vs ≥90 days) and duration of response (≥6.2 vs ≥4.7 months) after initial 3.2 mg/m².
This is a tight clinical-algorithm claim, not a broad “use lurbinectedin at 3.2 mg/m²” monopoly. It is most relevant for brand maintenance, generic/competitor “label design-around” risk, and litigation over method-infringement for clinicians who follow hematology-driven dose interruption and recovery schedules.
What does US 12,433,890 claim for lurbinectedin in metastatic SCLC?
Core independent claim logic (Claim 1; mirrored in Claim 26 variants):
- Treat metastatic SCLC with progression after platinum-based chemotherapy.
- Administer lurbinectedin monotherapy as follows:
- Prior dose: 3.2 mg/m² IV infusion (the trigger dose).
- If the patient previously experienced Grade 4 neutropenia or any-grade febrile neutropenia after the 3.2 mg/m² dose,
- then, within 35 days after receiving the 3.2 mg/m² dose, administer a 2.6 mg/m² IV infusion monotherapy dose.
- The 2.6 mg/m² dose must occur when, at administration time:
- platelets ≥ 100,000/mm³ and
- ANC ≥ 1,500 cells/mm³.
- Claim 1 also sets the patient selection (metastatic SCLC + post-platinum progression) and hematology recovery gating for re-dosing.
Key dependent claim clusters: regimen structure and arithmetic constraints
Treatment cycle and dosing frequency constraints
- Claim 2: one dose per cycle; cycle length 21 to 35 days; total lurbinectedin for 2 to 24 cycles.
- Claims 3–4: at least one cycle 22–35 days and/or at least one cycle 21 days.
- Claims 6–8: same type of cycle-length constraints for the 2.6 mg/m² regimen context.
Treatment duration (minimum cycle counts)
These are “coverage densifiers” for infringement by duration:
- Claim 17–19: 2.6 mg/m² for ≥4, ≥6, ≥10 cycles.
- Claim 20–22: 2.6 mg/m² with Claim 4 cycle condition for ≥4, ≥6, ≥10.
- Claim 23–25: 2.0 mg/m² for ≥4, ≥6, ≥10 cycles.
Step-down dosing after prior recovery from a given dose
The patent adds a second dose-step path:
- Claim 5 (and Claim 29 mirror): after initial re-dosing at 2.6 mg/m², if the patient subsequently experienced Grade 4 neutropenia or febrile neutropenia after the 2.6 mg/m² dose, then:
- within 35 days after receiving a 2.6 mg/m² dose,
- administer 2.0 mg/m² IV monotherapy,
- when platelets ≥ 100,000/mm³ and ANC ≥ 1,500 cells/mm³.
- Claims 6–8 apply cycle structure to that 2.0 mg/m² context.
Response duration thresholds tied to chemotherapy-free interval
Claims 9–16 insert clinical endpoints conditional on the chemotherapy-free interval:
- If initial 3.2 mg/m² was administered after chemotherapy-free interval ≥90 days, then duration of response (DoR) ≥ 6.2 months from that initial 3.2 mg/m².
- If initial 3.2 mg/m² was administered after chemotherapy-free interval <90 days, then DoR ≥ 4.7 months.
This is an unusual but enforceable pattern when the method requires the clinician to follow a regimen that results in those response-duration thresholds or when the claim is interpreted as method includes patient having that DoR characteristic.
What is the dosing-timing and hematology recovery “algorithm” in Claim 1 and Claim 26?
The algorithm is the patent’s core value. It ties together:
- a trigger dose (3.2 mg/m²),
- a toxicity outcome (Grade 4 neutropenia or febrile neutropenia),
- a time window (return within 35 days of that trigger dose), and
- two hematology gates at re-dosing (ANC ≥ 1,500 and platelets ≥ 100,000),
- followed by a defined next dose (2.6 mg/m²), with the same gates applied again for step-down to 2.0 mg/m² (after toxicity to 2.6).
Claim 26 adds mechanics that read like a “return-to-baseline” sequence
Claim 26 breaks the regimen into two explicit steps:
- (a) administer 3.2 mg/m² when ANC and platelets are adequate, but the patient then experiences Grade 4 neutropenia/febrile neutropenia.
- (a) requires the patient returns within 35 days to ANC ≥ 1,500.
- (b) then administer 2.6 mg/m² after ANC returns and platelets are adequate.
That makes Claim 26 structurally closer to a dosing-instruction claim and tends to be easier to map to clinical practice records than a pure “method” claim.
How does step-down dosing to 2.0 mg/m² broaden or narrow infringement risk?
The step-down logic creates a second “infringement ladder”:
- After toxicity at 2.6 mg/m², the patent claims a 2.0 mg/m² re-dosing pathway.
- That step uses the same gating and window:
- within 35 days of receiving the relevant prior dose,
- ANC ≥ 1,500 and platelets ≥ 100,000 at the time of administering 2.0 mg/m².
Practical effect: a clinician or protocol that stops lurbinectedin after toxicity at 2.6, or uses alternative dose levels not matching 2.6 → 2.0 sequencing within the same window/gates, can reduce exposure to this ladder. Conversely, dose reductions and re-escalations that follow this exact arithmetic are higher risk.
What treatment-cycle limitations are embedded in the claims?
Claim 2 defines cycle length and cycle count.
- Cycle length: 21 to 35 days
- Total lurbinectedin cycles: 2 to 24
Claims 3 and 4 “force” the presence of particular cycle lengths
- at least one cycle 22 to 35 days (Claim 3)
- at least one cycle 21 days (Claim 4)
Claim 6 and 7/8 repeat similar logic
- Cycle length: 21 to 35 days
- Total cycles: 3 to 24 (in the context of the 2.6-step regimen)
- at least one cycle 22–35 and/or 21 days.
Claims 27 and 28 similarly apply:
- for Claim 26-derived regimen: cycle length 21–35 days and 4–24 cycles, plus at least one 21-day cycle.
Claim 17–26 add minimum cycle counts for specific dose levels
Minimum cycle counts create a risk surface for trials or protocols that extend treatment beyond early discontinuation. If a generic enters and is followed for fewer cycles, a minimum-cycle claim may be easier to avoid.
What patient-selection and endpoint filters create claim narrowing?
The patent narrows the covered population in two ways:
- Disease-state filter: metastatic SCLC with disease progression after platinum chemotherapy.
- Hematology and toxicity filter: Grade 4 neutropenia or febrile neutropenia from a prior lurbinectedin dose, followed by recovery meeting ANC and platelet thresholds.
- Time window filter: re-dosing must occur within 35 days of the trigger dose.
- Optional DoR filter tied to chemo-free interval:
- chemo-free interval ≥90 days implies DoR ≥6.2 months;
- chemo-free interval <90 days implies DoR ≥4.7 months.
These filters collectively narrow the infringement map to patients whose real-world course follows the claimed hematology trajectory and the re-dosing timing.
How strong is the claim scope likely to be for method-of-use litigation?
From claim structure alone:
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Strength factors:
- Specific quantitative dose amounts (3.2, 2.6, 2.0 mg/m²) and dosing transitions.
- Specific gating thresholds (ANC ≥1,500; platelets ≥100,000).
- Specific timing window (within 35 days).
- Specific cycle-length and minimum-cycle constraints.
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Vulnerability factors:
- Method claims depend on clinician actions and patient conditions. A generic that challenges labeling or practice may be able to argue non-infringement by divergence from cycle length, number of cycles, timing, or the hematology thresholds.
- Endpoint-based dependent claims (DoR thresholds) can become a proving issue unless litigation accepts that those thresholds are inherent to the claimed method or can be established via trial/real-world data.
Net: the estate is best positioned as an “algorithm” claim to deter close follow-on regimen copying, not as a broad product-use monopoly.
Does this patent cover label-adjacent regimens, or only this specific reduction scheme?
Based strictly on the claims provided:
- The patent’s coverage is concentrated on monotherapy lurbinectedin with the defined step-down sequence and defined re-dosing timing after specific hematologic toxicity.
- Alternative dose reductions (other than 2.6 and 2.0 mg/m² after 3.2 and 2.6, respectively), other time windows (not “within 35 days”), or different hematology cutoffs would fall outside the literal claim language.
What generic entry risks exist for lurbinectedin methods in metastatic SCLC post-platinum progression?
For small-molecule drugs like lurbinectedin, generic entry risk is mediated by:
- whether there is an Orange Book-listed US method patent covering the relevant regimen, and
- whether Paragraph IV or subsequent litigation addresses method-infringement under the claimed algorithm.
This patent, by its algorithmic specificity, creates a litigation pathway where brand argues that use under FDA labeling and clinical practice meeting the claimed windows infringes the method claims, while generic challengers argue design-around by altering re-dosing timing, dose reduction levels, cycle schedule, or treatment duration.
What is the patent landscape around US 12,433,890 (related patents, continuations, and claim strategy)?
The prompt provides only the claim text for US 12,433,890, not the bibliographic family data, assignee, priority, prosecution history, or other asserted patents. Without that information, an accurate landscape cannot be reconstructed.
What can be inferred from the claim set itself:
- The claim drafting shows a modular approach (independent claim + dependent cycles + dependent minimum-cycle counts + dependent step-down + dependent DoR by chemo-free interval), which is typical of continuations or divisional claim sets aiming to preserve coverage across multiple clinical subgroups and regimen lengths.
- The presence of multiple dosing ladders (3.2 → 2.6 and 2.6 → 2.0) and multiple duration thresholds suggests the application likely targeted a specific clinical dataset and then layered claims to cover both the standard and “toxicity-recovery” dosing paths.
No additional patent numbers, assignees, jurisdictions, or related filings can be stated from the provided content.
Which parts of these claims are most likely to be asserted in litigation?
Based on provability and day-to-day relevance:
- Independent claim 1 or 26 (core algorithm: 3.2 mg/m² trigger dose, toxicity, within 35 days re-dosing to 2.6 at ANC/platelets gates).
- Step-down claims 5 / 29 (2.6 → 2.0 ladder).
- Cycle-length and minimum-cycle claims (claims 2–4, 6–8, 17–25, 27–28) for strengthening damages/coverage based on real-world regimen length.
DoR-by-chemo-free-interval claims (9–16) can be asserted but will depend heavily on evidentiary framing: whether plaintiffs can show the patient populations meet those thresholds or whether the method is construed as including that endpoint outcome.
Key Takeaways
- US 12,433,890 claims a specific lurbinectedin monotherapy re-dosing algorithm for metastatic SCLC post-platinum progression: after Grade 4 neutropenia or febrile neutropenia from prior dosing, the patient is re-dosed within 35 days when ANC ≥1,500 and platelets ≥100,000, at 2.6 mg/m² following 3.2 mg/m², and optionally 2.0 mg/m² following 2.6 mg/m².
- The patent adds regimen-structure limitations: cycle length 21–35 days, constrained cycle counts, and minimum cycle counts at the 2.6 and 2.0 doses.
- Several dependent claims tie duration of response thresholds to chemotherapy-free interval strata (≥90 vs <90 days).
- The scope is narrow-to-medium in practice: it is hard to infringe without following the claimed dosing ladder, time window, hematology gates, and cycle/treatment-duration constraints.
FAQs
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Does US 12,433,890 require the initial 3.2 mg/m² dose to be given after platinum chemotherapy progression?
Yes. The patient must have metastatic SCLC with disease progression after platinum-based chemotherapy.
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What hematology thresholds are required to redose at 2.6 mg/m²?
ANC must be at least 1,500 cells/mm³ and platelets at least 100,000/mm³ at the time of the 2.6 mg/m² dose.
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What toxicity event triggers the 35-day re-dosing window?
Grade 4 neutropenia or any-grade febrile neutropenia following the prior lurbinectedin dose.
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What are the defined dose reductions in the claim set?
From 3.2 → 2.6 mg/m², and optionally from 2.6 → 2.0 mg/m², each using the same within-35-days and hematology gate conditions.
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Do the claims cover combinations of lurbinectedin with other therapies?
The claims recite lurbinectedin as monotherapy, so combination regimens are outside the literal claim language.
References
- US Patent 12,433,890 (claims excerpt provided in prompt).
