Phase II trial of irinotecan and carboplatin for extensive or relapsed small-cell lung cancer

Purpose The regimens of weekly irinotecan with platinum have been used for treatment of metastatic small-cell lung cancer (SCLC). We conducted a multi-institution phase II trial to evaluate a novel 21-day schedule of irinotecan and carboplatin in patients with relapsed or extensive SCLC. Patients and Methods Eighty patients were enrolled with the following characteristics: 39 male patients, 41 female patients; median age, 65 years; and Zubrod performance status, 0 to 1 in 85% and 2 in 15% of patients. Dosing schemas were based on the maximum-tolerated dose derived in a previous phase I study. Chemotherapy-naive patients with extensive SCLC were treated with irinotecan 200 mg/m² and carboplatin area under the curve (AUC) of 5 (arm A). Patients, who had previously been treated with chemotherapy and had relapsed disease received irinotecan 150 mg/m² and carboplatin AUC of 5 (arm B). In each study arm, the treatment was given every 21 days for up to six cycles. Results The most common grade 3 to 4 toxicities included neutropenia (54%), thrombocytopenia (22%), anemia (13%), diarrhea (22%), and nausea/emesis (11%) in both study arms. There were three treatment-related deaths owing to neutropenic sepsis. Among 72 assessable patients, response rates of 65% and 50% were observed, respectively, for arm A and arm B. The median survival for both study arms was identical at 10 months (95% CI, 6 to 14 months). A response rate of 65% was observed in the intracranial disease of 14 patients with known brain metastases. Conclusion This 21-day regimen of irinotecan and carboplatin seems promising for the treatment of relapsed SCLC.