Asparaginase and methotrexate combination chemotherapy in relapsed acute lymphoblastic leukemia in adults.

We have treated 37 adults with acute lymphoblastic leukemia (ALL), who have relapsed on previous intensive chemotherapy, with a combination of L-asparaginase and methotrexate (MTX) +/- ifosfamide. The initial study included 26 patients who received the two-drug combination of L-asparaginase and MTX given sequentially. Of the 26 patients, 15 (58%) achieved complete remission (CR), while 3 patients had a partial remission (PR), resulting in an overall response rate of 69%. The median duration of CR was 17.5 weeks. The median survival of complete responders was 39 weeks compared with 10 weeks for failures (P=0.001). The regimen was generally well tolerated and it was possible to give MTX doses of up to 400 mg/m2 with minimal myelosuppression, and severe stomatitis was infrequent. A further study involved the use of this regimen combined with ifosfamide in 11 patients. In this continuing study, there were six CR's (55%) and two PR's, with an overall response rate of 73%. The median duration of CR was 14+ weeks, and the median survival was 40+ weeks. Combination chemotherapy with asparaginase and MTX is effective in inducing remission in adults with ALL in relapse. It should now be considered for inclusion as part of induction therapy of previously untreated adults with ALL.