Vincristine in acute leukemia of childhood

Ninety‐four children with acute leukemia refractory to other forms of chematherapy were treated by three dosage regimens of vincristine. Complete remission occurred in 21.8% of the children experiencing adequate drug trial, with partial remission in 25.4% and bone marrow remission in 37.4%. Rapidity of response was variable with bone marrow remission occurring between the fourteenth and eighty‐fifth day of therapy and optimum response between the twenty‐first and one hundred and thirteenth day. Remissions, lasting only 20‐154 days, on maintenance therapy with vincristine tended to be relatively short‐lived, compared with those maintained by other agents. Toxicity of vincristine proved to be a limiting lactor, requiring alteration of therap in over 25% of the children treated. Vincristine, nevertheless, is firmly established as a valuable agent for the induction of remission in acute leukemia. Continuing studies indicate that the rate of remission reinduction is markedly increased by the combination of vincristine with prednisone.