Phase II study of mitolactol in metastatic malignant melanoma

The Central Pennsylvania Oncology Group conducted a phase II study of mitolactol in advanced metastatic melanoma to determine the overall survival rate and duration of response to this agent. The starting dose was 100 mg/m2/day orally. If no hematologic toxicity was noted on weekly blood cell counts, the dose was increased to 130 mg/m2/day on Day 35, and, if still tolerated, to 160 mg/m2/day on Day 70. Six of 25 evaluable patients (24%) had objective partial response. The median duration of response was 20 weeks, with a range of 10-66 weeks. Six of 25 patients (24%) had stable measurable disease, with a median duration of 9 weeks. The median survival from date of entry in this study was 21 weeks in responding or stable patients compared to 7 weeks in nonresponders. Hematologic toxicity was the dose-limiting factor. This study shows that mitolactol has moderate activity against advanced melanoma, and the drug deserves further study in combination with nonmyelotoxic drugs.