A Preliminary Report on Vincristine Sulfate—a New Active Agent for the Treatment of Acute Leukemia

In a group of 13 children with "advanced refractory" acute leukemia, a minimal complete remission rate of 54% was obtained with vincristine sulfate treatment. The 95% confidence limits are between 25% and 81%. The remission rate for vincristine is therefore of the same order as that for 6-mercaptopurine (6-MP), methotrexate (MTX), and corticosteroids. The effect on remission duration could not be accurately determined. These results indicate that prolongation of survival depends directly on the achievement of remission and that children with advanced leukemia refractory to 6-MP and MTX are capable of responding to new classes of active agents. Serious neurological toxicity was observed in a few patients who received doses larger than 0.1 mg/kg for long periods of time.