Treatment-Free Remission in Ph+ ALL Without Allogeneic Stem Cell Transplantation: Current Evidence and Future Directions.

Over the past two decades, the treatment landscape of Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) has undergone a profound transformation. Once considered the subtype with the worst prognosis, Ph+ ALL is now associated with the possibility of long-term survival in a significant proportion of patients. This dramatic improvement has been driven by the advent of tyrosine kinase inhibitors (TKIs) and, more recently, by the incorporation of blinatumomab, a bispecific T-cell engager antibody, into frontline therapeutic strategies. In this evolving context, two major areas have become the focus of clinical investigation: on the one hand, the identification of high-risk patients who truly benefit from allogeneic hematopoietic stem cell transplantation (allo-HSCT); on the other, the characterization of patients who can achieve durable responses without transplantation and who may be candidates for treatment discontinuation of TKIs. This review aims to summarize the current evidence supporting the concept of treatment-free remission (TFR) in Ph+ ALL.