L-Asparaginase as a single agent in acute lymphocytic leukemia: survey of studies form Childrens Cancer Study Group.

A series of studies were undertaken by the Childrens Cancer Study Group between 1968 and 1972 to evaluate the optimum schedule and dosage of L-asparaginase as a single agent in induction and maintenance of children with previously treated acute lymphocytic leukemia. Six different dosages of enzyme were administered (3600-840,000 IU/4 wk/m2). The optimal dose of L-asparaginase was found to be 12,000 IU/m2 given three times per week for a total dose of 144,000 IU/m2. Sixty-three percent of children treated with this dosage achieved a bone marrow remission. The intramuscular method of administration is as effective and produced less significant sensitivity reactions than the intravenous method. Reinduction, after an unmaintained remission, with L-asparaginase was possible in 32% of the cases. L-Asparaginase used as a maintenance agent did not result in a significant increase in remission duration when compared to no maintenance therapy. However, patients who received L-asparaginase maintenance had a median remission duration of 66 days as compared to 41 days for the no-maintenance group.