Rituximab added to standard chemotherapy and its effect on minimal residual disease during induction in CD20 positive pediatric acute lymphoblastic leukemia: a pilot RCT.

The use of rituximab in the treatment of pediatric acute lymphoblastic leukemia (ALL) has been evaluated but mostly this has been done in the setting of a relapsed or refractory disease. Addition of rituximab to the initial treatment regimen improves the outcomes in adult CD20 positive ALL. This study was done to study its effect on newly diagnosed CD20 positive pediatric ALL patients. Twenty pediatric patients with CD20 positive ALL were randomly assigned to receive rituximab along with standard-chemotherapy [Intervention-arm (IA)] or standard-chemotherapy alone [Standard-arm (SA)]. The absolute blast count (ABC) on day 8, flowcytometry-MRD levels in the peripheral blood (PB) on day-8, day-15 and in the bone marrow (BM) at end of induction (EOI) were the outcome variables. Baseline characteristics were comparable between the IA (n=10) and SA (n=10). Significantly lower day-8 ABC was seen in the IA (P=0.005). The day-8 PB-MRD showed lower values for the IA but the difference wasn't significant (P=0.22). There was no difference between the IA and SA for day-15 PB-MRD and EOI BM-MRD. There was no difference in the incidence of adverse effects. Rituximab added to standard-chemotherapy lead to lower day-8 ABC and lower day-8 PB-MRD in CD20 positive pediatric ALL patients. Rituximab may be beneficial in pediatric ALL treatment. Studies with larger sample size are needed for more evidence.