No advantage of a rotational continuation phase in acute lymphoblastic leukemia in childhood treated with a BFM back-bone therapy

Background Our aim was to compare two different schedules of maintenance in pediatric acute lymphoblastic leukemia (ALL) treated with a BFM‐based therapy, in a randomized study: an Arm with 6‐MP + MTX (with or without vincristine and dexamethasone pulses) versus a more intensive continuation phase. Procedure From January 1996 to November 2002, 429 eligible children with ALL were enrolled in a protocol with BFM‐based back‐bone, followed by a randomized continuation phase in standard (SRG) and intermediate (IRG) risk groups. Patients were randomized between Arms A and B for SRG and B or C for IRG. Arms A and C consisted of 6‐MP and MTX and in Arm C, six pulses of VCR and dexamethasone were added. Arm B combined four pairs of drugs rotated weekly. All risk‐groups received maintenance until completing 2 years of therapy from diagnosis. Results With a median follow‐up of 138 (range: 96–178) months, the overall pEFS (SE) was 72 (6)% for all patients and the different risk groups showed: SRG: 85 (3)%, IRG: 71 (1)%, and HRG: 42 (7)% (P‐value ≤0.0001). The pDFS (SE) according to the assigned arm of maintenance was, for Arm A: 89 (3)% and for Arm B: 85 (4)% in SRG, and, for Arm B: 77 (4)% and for Arm C: 75 (4)% in IRG, at 10 years follow‐up. There were no statistically significant differences in outcome between arms of maintenance for both risk groups. Conclusions In protocols with initial BFM‐based strategy, a more intensive continuation phase did not benefit any risk group of patients. Pediatr Blood Cancer 2011;57:47–55. © 2011 Wiley‐Liss, Inc.