Phase II/III study in children and adolescents with newly diagnosed B-cell precursor acute lymphoblastic leukemia: protocol for a nationwide multicenter trial in Japan.

B-cell precursor acute lymphoblastic leukemia is the most common pediatric malignancy, but its treatment needs to be modified to cause low acute toxicity and few late complications with a high cure rate. In this trial, we will stratify patients with B-cell precursor acute lymphoblastic leukemia into standard, intermediate and high risk groups according to prognostic factors. In addition, we will establish an evaluation system for minimal residual disease that will enable us to stratify patients based on minimal residual disease in subsequent clinical trials. We will clarify the impact of dexamethasone/vincristine pulse therapy during maintenance therapy in the standard risk group, and intensive l-asparaginase therapy in the intermediate risk group. In the high risk group, usefulness of vincristine intensification will be assessed. This trial has been registered in the UMIN Clinical Trials Registry as UMIN000009339 [https://www.umin.ac.jp/ctr/].