L-asparaginase used with cytosine arabinoside in treatment of childhood acute lymphocytic leukemia refractory to vincristine and prednisone.

Eleven patients with acute lymphocytic leukemia in relapse were treated with L-asparaginase and cytosine arabinoside (1-beta-D-arabinofuranosylcytosine) in induction therapy and the same drugs plus cyclophosphamide in maintenance therapy. Three patients had complete remissions lasting 6, 16, and 78+ weeks. One patient experienced partial remission and four had decreased bone marrow or peripheral blasts but were not clinically improved. The responses, which were brief, lasted 1-16 weeks with one exception of 78+ weeks. Four patients had allergic reactions to L-asparaginase that were unpredictable with assays of antibodies against L-asparaginase.