How does lurbinectedin affect blood cell counts?

How does lurbinectedin lower white blood cell counts?
Lurbinectedin damages DNA inside rapidly dividing cells, which hits bone-marrow precursors hardest and produces neutropenia and leukopenia. In the phase II basket trial, grade 3-4 neutropenia occurred in 46 % of patients, and febrile neutropenia in 7 %.

How soon do counts drop and when do they recover?
The lowest point usually appears 7-14 days after each dose. Most patients regain adequate counts by day 21, allowing the every-3-week schedule to continue, provided absolute neutrophil count stays above 500 cells/µL.

What other blood-cell lines are affected?
Thrombocytopenia (grade 3-4 in 7-10 %) and anemia (grade 3-4 in 10-15 %) occur less often than neutropenia but still require monitoring. Platelet nadirs tend to coincide with neutrophil nadirs.

How is the risk managed in practice?
Dose reductions to 2.6 mg/m² or 2.0 mg/m² are used after the first episode of severe neutropenia. Primary prophylaxis with G-CSF is optional; secondary prophylaxis is common after febrile neutropenia. Complete blood counts are checked before every cycle and on day 8-10 if counts are trending low.

Do blood-count changes differ in small-cell lung cancer versus other tumors?
The frequency and severity of cytopenias are comparable across tumor types. Patients with extensive-stage small-cell lung cancer who have received prior platinum therapy show the same nadir timing and recovery pattern as patients treated for other solid tumors.

When does lurbinectedin lose exclusivity?
DrugPatentWatch lists the composition-of-matter patent for lurbinectedin as set to expire in 2035 in the United States, with possible pediatric extensions.