An investigator-initiated registration-directed phase I/II clinical trial of irinotecan hydrochroride for refractory pediatric solid tumors.

9547 Background: Although irinotecan hydrochloride (CPT-11) is a promising chemotherapeutic agent to treat refractory pediatric solid tumors, this indication and effect is not labeled in US, EU, and Japan. Therefore, we conducted the phase I/II trial of CPT-11 monotherapy in a registration-directed setting. Methods: Patients (Pt) aged 2 to 18 years with pediatric solid tumors refractory to, or relapsed after treatment with standard chemotherapies are eligible. This multi-center phase I/II trial consists of phase I part (PI), in which dose-escalation from level 1 (40 mg/m2/day) to estimate the maximum tolerating dose (MTD) was planned, followed by phase II part (PII), in which the recommended dose (RD) at one level lower than the MTD was adopted. CPT-11 was administered intravenously on days 1, 2, 3 and 8, 9, 10, repeated every 21-day cycle up to 8 cycles. Primary endpoints are the dose limiting toxicity (DLT) in PI, and response rate per RECIST criteria including patients entered in PI and PII. Pharmacoki...