PURPOSE: This multicenter phase II trial was performed to determine tumor efficacy and tolerance of the oral platinum drug JM216 in patients with small-cell lung cancer (SCLC). PATIENTS AND METHODS: Patients with SCLC limited disease unfit for intensive chemotherapy or those with extensive disease received JM216 120 mg/m(2)/d for 5 consecutive days every 3 weeks. Individual dose escalation to 140 mg/m(2)/d was allowed if toxicity was </= grade 2 according to the National Cancer Institute Common Toxicity Criteria. Tumor response was evaluated according to World Health Organization criteria. RESULTS: Twenty-seven patients were assessable for toxicity and 26 for tumor response. Eighty-eight cycles were administered. Common Toxicity Criteria grade 3 and 4 hematologic toxicities were neutropenia in 15.9% and 3.7%, lymphocytopenia in 47.6% and 17.1%, and thrombocytopenia in 19.5% and 10.3% of cycles, respectively. One patient suffered from neutropenic fever. Nausea, vomiting, and diarrhea were the most common nonhematologic toxicities. Except for grade 4 diarrhea in one patient, no grade 4 nonhematologic toxicity was observed. No severe neurotoxicity or nephrotoxicity was observed. Tumor response rate was 10 of 26 (38%; 95% confidence interval, 19% to 58%), excluding five unconfirmed partial responses. No complete responses were observed. Median overall time to progression was 110 days (range, 5 to 624 days). Median overall survival time was 210 days (range, 5 to 624 days). CONCLUSION: Oral JM216 is active in previously untreated patients with SCLC and shows mild toxicities.