Phase II study of irinotecan and carboplatin in patients with the refractory or relapsed small cell lung cancer.

We examined the safety and efficacy of the combination of irinotecan plus carboplatin in patients with refractory or relapsed small cell lung cancer (SCLC). Patients with previously treated SCLC were eligible. Patients were treated every 3 weeks with carboplatin (with a target area under the concentration versus time curve of 5 mg min/ml using the Calvert formula on day 1) plus irinotecan (50 mg/m(2) on days 1 and 8). From May 2000 to January 2002, 24 patients were eligible. None of the 22 patients achieved a complete response, but 15 achieved a partial response with an overall response rate of 68.2% (95% confidence interval, 45.1-86.1%). In 13 patients with sensitive disease, the response rate was 92.3% (95% confidence interval, 64.0-99.8%). The median survival time (MST) was 194 days (range 27-605 days). The MST did not differ significantly between patients with sensitive disease (245 days) and those with refractory disease (194 days, P=0.88). One patient died of treatment-related sepsis. Grade 3-4 hematologic toxicities included leukopenia in 58% of patients, neutropenia in 63%, thrombocytopenia in 58%, and anemia in 67%. Grade 3 diarrhea developed in 21% of patients and grade 3-4 infection in 13%. No patients had grade 4 diarrhea or grade 3-4 nausea and vomiting. This regimen is effective and well tolerated in patients with relapsed or refractory SCLC. However, the search for even more active regimens should be continued.