Repeated use of L-asparaginase in multi-drug therapy of childhood leukemia.

The capacity of 1-asparaginase in two separate schedules (consecutive and intermittent), along with vincristine and prednisone to produce multiple responses, was evaluated in previously treated children with acute leukemia in relapse. The response rates varied inversely with previous 1-asparaginase exposure. A history of prior resistance to prednisone and vincristine appeared to reduce the response rate. Hypersensitivity reactions occurred in 14%.