Protracted vinblastine infusion. Phase I-II study in malignant melanoma and other tumors

Twenty-six patients received vinblastine by ambulatory pump infusion via the subclavian vein for a median duration of 30 days of continuous therapy at an average dose rate of 0.5 mg/m2/day. Drug toxicity was minimal compared to the standard bolus schedule but bone marrow suppression was dose-limiting. There was no gastrointestinal or neurologic toxicity. The maximum duration of continuous therapy was 89 days (at 0.5 mg/m2/day) with the duration of therapy specifically related to the daily dose rate. Nondrug-related toxicity included subclavian vein thrombosis in two patients. Two of 11 patients with malignant melanoma had transient objective responses and 1/3 patients with soft tissue sarcoma had a partial response. Expanded phase II studies are ongoing at the dose of 0.5 mg/m2/day for a minimum duration of 30 days.