Phase II Study of Carboplatin in Small Cell Lung Cancer

Carboplatin (CBDCA; cis-diammine-1, 1-cyclobutane dicarboxylateplatinum II), a new platinum analogue, was administered to 18patients with small cell lung cancer (SCLC) at a dose of 300–450mg/m² intravenously every four weeks, in a phase II study. Allpatients could be evaluated to assess response and 17 for toxicity.The overall response rate was 28% (5/18), including one completeresponse. Of eight patients previously untreated, four (50%)showed a response, including one complete response. The responserate in patients with no previous cisplatintreatment was 50%(5/10). Response durations in five responders were 2, 3, >4,> 10 and 11 months. Toxicity was primarily hematologic,with thrombocytopenia being dose-limiting. Thrombocytopenia(<75,000/mm³) was observed in 12 patients (71%), six requiringplatelet transfusion. Leukopenia (<3,000/mm³) was observedin 11 patients (65%). There were no episodes of serious infectionor bleeding, however. Myelosuppression was more severe in heavilypretreated patients than in patients previously untreated. Dosereductions were required following multiple treatments for cumulativemyelotoxicity. Mild to moderate nausea and vomiting occurredin seven patients (44%). Nephrotoxicity and ototoxicity werenot observed. Carboplatin was demonstrated to be an active agentagainst SCLC. Further investigation into dose and schedule ofCBDCA in combination chemotherapy is warranted.