Treatment of children with early pre-B and pre-B acute lymphocytic leukemia with antimetabolite-based intensification regimens: a Pediatric Oncology Group Study

Between May 1987 and January 1991, 1354 patients, 1-21 years old, with stan dard or poor prognosis B-lineage acute lymphocytic leukemia were treated on the Pediatric Oncology Group Study 8602. One thousand three hundred and tw enty-three patients entered remission and 1051 patients were randomized on day 43 to an intensification regimen containing L-asparaginase and intermed iate-dose methotrexate (regimen B) or cytarabine and intermediate dose meth otrexate (regimen C). After completion of intensification at week 25, all p atients received the same maintenance therapy until 3 years from diagnosis. Overall 5-year continuous complete remission (CCR) for regimen B was 72 +/ - 2% (s.e.) and for regimen C, 73 +/- 2% (P = 0.72 by log-rank analysis). S ignificant differences between treatments for CCR, testicular, CNS relapses overall or with regard to phenotype (pre-B vs early pre-B), gender, or rac e were not detected. During intensification, regimen C had significantly mo re bacterial infections (P= 0.05) and days spent in the hospital (P < 0.001 ) compared with regimen B, while regimen B had significantly more allergic reactions (P < 0.0001). No significant differences in CCR were noted betwee n patients with pre-B and early pre-B ALL(P= 0.22 stratified by risk group and treatment). This study was unable to detect statistical difference betw een asparaginase (regimen B) and cytarabine (regimen C) during the intensif ication phase of therapy in children with B-lineage acute lymphocytic leuke mia.