Purpose: Sixty patients with metastatic melanoma were treated in a phase II study with the imidazotetrazine derivative temozolamide to assess further the efficacy demonstrated in previous phase I studies.
Patients and methods: Fifty-five of 56 eligible patients were assessable for toxicity and 49 for response. The patients received temozolomide 150 mg/m2/d over 5 successive days orally (total dose, 750 mg/m2) in the first course. Courses were repeated every 4 weeks and the dose was escalated to 200 mg/m2/d x 5 (total dose, 1 g/m2) after the first course if toxicity was acceptable. Patients were all chemotherapy-naive, except for two who had previously received interferon alfa and one who had received interleukin-2 (the latter patient had also received two phase I drugs some time previously).
Results: A complete response (CR) was documented in three patients (all with lung metastases) and a partial response (PR) in nine patients (21% CR plus PR rate). Seven of 56 patients were not assessable for response because of early death or deterioration. The overall response rate excluding these patients is 12 of 49 (24%). The median response duration was 6 months (range, 2.5 to 22+). Toxicity of the regimen, which was mainly hematopoietic, was low. The median survival duration for all patients was 5.5 months (range, 0.5 to 29.5). For responders, the median survival duration was 14.5 months (range, 3 to 28+), with four patients still alive.
Conclusion: Temozolomide in the schedule used has as good activity in chemotherapy-naive metastatic melanoma as the other most active agents currently in use. Further studies of the drug on its own and in combination with other agents is recommended.