Treatment of childhood acute lymphoblastic leukemia: randomized trials of protocols CCLSG-L 841 and I 841. (Phase III study). Children's Cancer and Leukemia Study Group

From 1984 to 1987, 144 previously untreated children with low (LR) or intermediate-risk (IR) acute lymphoblastic leukemia (ALL) were entered in the protocol L 841 or I 841, respectively. The patients in the LR group were randomized to receive regimen A (L 841 A) or B (L 841 B) and the patients in the IR group were randomized to receive regimen B (I 841 B) or C (I 841 C). L 841 A consisted of vincristine (VCR) + prednisone (PDN) for the remission induction phase and 18 Gy cranial irradiation combined with intrathecal methotrexate (MTX) for the central nervous system (CNS) leukemia prophylaxis. The maintenance phase consisted of MTX iv alternating 5-day course of VCR + PDN + 6-mercaptopurine (6MP) at 2 wk-interval. In L 841 B, I 841 B and I 841 C, asparaginase (ASP) was added as a third drug. Adriamycin (ADM) and high-dose MTX (100 mg/kg) were additionally employed in the intensive phase of I 841 C. Thirty-nine, 20, 25 and 49 eligible patients were entered in L 841 A, L 841 B, I 841 B and I 841 C, respectively. The event free survival rate in each regimen was 50.5% +/- 13.7% (M +/- SE), 100% +/- 6.0% (p less than 0.01), 72.7% +/- 9.8% and 40.7% +/- 13.2% (p less than 0.1) at 4 years, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)