Chemotherapy or Hematopoietic Stem Cell Transplantation in B-Lineage Acute Lymphoblastic Leukemia Patients Based on IKZF1 and MRD Status

Purpose： We aimed to investigate the outcomes of different post-remission treatment choices based on IKZF1 detection by RT-PCR and dynamic measurable residual disease (MRD) by multiparameter flow cytometry in B-ALL. Prospectively confirm the role of MRD and IKZF1 deletion as a significant predictor of post-remission treatment, replacing the definition of clinical risk categories for patients after complete remission (CR). Patients and Methods： There were 202 patients with B-ALL enrolled in this registry-based cohort study including 99 who received chemotherapy (CMT), and 103 allogeneic stem cell transplantation (allo-SCT). The primary endpoint was the 5-year overall survival (OS), event-free survival (EFS), and cumulative incidence of relapse (CIR). Subgroup analyses were performed based on IKZF1deletion and dynamic MRD 14,24,45 days after induction therapy. Results： In subgroups of patients with IKZF1wt and MRD negative patients， the 5-year overall survival (OS), event-free survival (EFS), and cumulative incidence of relapse(CIR) probabilities for patients assigned to chemotherapy were 67.6%, 55.2%,36.5% and 71.4%,60.7%,28.6%, for those assigned to HSCT respectively. In subgroups of patients with IZKF1 del or MRD positive patients after CR, with OS, EFS, and CIR rates for patients assigned to chemotherapy were 30.1%, 10.3% and76.2%, and 71.8%, 39.8%, and 43.7%for those assigned to HSCT, respectively. Conclusion： The results thus suggest a clear distinction between HSCT and CMT inIKZF1del or MRD positive Patients. While IKZF1wt patients and MRD negative had significant differences. Affected patients should thus be carefully monitored for IKZF1 and minimal residual disease to decide on the post-remission treatment after CR.