Role of Allogeneic Hematopoietic Stem Cell Transplantation for Philadelphia Chromosome-Positive B-Cell Acute Lymphoblastic Leukemia in the Contemporary Era

The treatment of Philadelphia chromosome-positive B-cell acute lymphoblastic leukemia (Ph+ B-cell ALL) has seen substantial progress over the past two decades. The introduction of BCR::ABL1 tyrosine kinase inhibitor (TKIs) has resulted in dramatic improvements in long-term survival. Allogeneic hematopoietic stem cell transplantation (allo-HSCT), with its curative potential, has always been an integral part of the treatment algorithm of Ph+ ALL. Recently, the approval of novel therapies such as blinatumomab, inotuzumab ozogamicin and chimeric antigen receptor T-cell (CAR-T) therapy in relapse and refractory (R/R) ALL have further improved outcomes of B-cell ALL. With potent TKIs and novel targeted therapy, the treatment guidelines for Ph+ ALL are evolving rapidly. Additionally, with improved tools for detecting measurable residual disease (MRD), there has been recent interest in redefining the role of allo-HSCT for some patients. In this context, we discuss the current evidence for the utilization of allo-HSCT for Ph+ ALL, focusing on novel therapies and MRD-directed care.