Favorable response to maintenance therapy of second or subsequent remissions in childhood acute lymphocytic leukemia.

Twenty-two children with acute lymphocytic leukemia (ALL) who had relapsed while on therapy and for whom remissions were successfully reinduced were maintained with a combination of methotrexate, daunomycin, 6-mercaptopurine, prednisone, and vincristine (Djerassi-methotrexate with BOMB). The median duration of remission was 35 weeks (range, five to 364+ weeks). Of 8 children (36%) did not relapse while receiving this therapy, 4 are off all therapy (durations of remissions, 40+, 97+, 132+, and 216+ weeks). Improved responses were found in children with platelet counts of greater than 10(5)/mm3 at the time of index relapse. Intrathecal chemotherapy seemed to greatly prolong the duration of remission for 16 children when compared to those children who did not receive IT therapy (45.5 vs. 24 weeks). No central nervous system relapses occurred. This maintenance regimen for children with previously relapsed ALL appears to be effective and worth additional clinical trials.