A phase I study and pharmacologic evaluation of irinotecan and carboplatin for patients with advanced ovarian carcinoma who previously received platinum-containing chemotherapy

BACKGROUND. The objectives of the current study were to determine the maximum tolerated dose (MTD) of irinotecan and carboplatin in combination, to evaluate the efficacy and toxicity of the combination in patients with advanced ovarian carcinoma who previously received platinum-containing chemotherapy, and to examine the pharmacokinetics and pharmacodynamics of both drugs by using the Chatelut formula. METHODS. Patients with advanced ovarian carcinoma who previously received platinum-containing chemotherapy were treated with a combination of irinotecan and carboplatin. Carboplatin was administered as a 60-minute intravenous infusion on Day I and was followed by irinotecan, which was administered as a 90-minute intravenous infusion on Days 1, 8, and 15. Six dose levels of irinotecan (in mg/m(2))/carboplatin (mg center dot mL/min) were planned: 50 mg/m(2)/4 mg center dot mL/ minute, 60 Mg/M-2/4 mg center dot mL/minute, 50 mg/m(2)/5 mg center dot mL/minute, 60 mg/m(2)/5 mg . mL/minute, 50 mg/m(2)/6 mg center dot mL/minute, and 60 mg/m(2)/6 mg center dot mL/minute. The carboplatin dosage was calculated by using the Chatelut formula. Treatment was repeated at 28-day intervals. RESULTS. in total, 19 patients in cohorts of 3 to 5 patients received irinotecan and carboplatin at 5 dose levels. The dose-limiting toxicities were Grade 4 neutropenia and Grade 4 thrombocytopenia. The MTD of the irinotecan/carboplatin combination was 60 Mg/M2/5 . mg mL/minute. Partial responses were observed at higher dose levels. Pharmacologic studies demonstrated that administration of the dosage estimated with the Chatelut formula instead of the Chatelut formula with adjustment for serum creatinine resulted in a slightly excessive dose of carboplatin. CONCLUSIONS. The recommended dose for the Phase 11 study was irinotecan 60 Mg/M-2 on Days 1, 8, and 15 with carboplatin 5 mg/mL . minute on Day I repeated every 4 weeks.