Intravenous vincristine infusion: phase I trial.

In an attempt to sustain potentially cytotoxic concentrations of vincristine in man, a five-day continuous infusion of vincristine after an initial intravenous bolus injection was administered to 30 patients with refractory malignancies. Three dosage levels were explored (0.5 mg/m2, 0.75 mg/m2, and 1.0 mg/m2 daily for five days). Neurologic and hematologic toxicity were severe at the high dose level, whereas mild to moderate toxicity occurred at the 0.5 and 0.75 mg/m2 dose levels. Objective responses were noted in 11 patients (37%) with the following malignancies: non-Hodgkin's lymphoma (4), acute non-lymphoblastic leukemia (2), chronic granulocytic leukemia in blast crisis (1), carcinoma of the breast (3), and small cell carcinoma of the lung (1). Responses were observed at each infusion dose level. Nine of the 11 responders had previously progressed while receiving conventional intravenous bolus injection of vincristine. These data suggest that the clinical usefulness of vincristine may be enhanced by the use of infusion techniques. A maximum daily dose of 0.5 mg/m2 given for five days is recommended for future trials of intravenous vincristine infusion.