The role of stem cell transplantation in the management of Philadelphia chromosome

The concurrent administration of tyrosine kinase inhibitors (TKIs) with standard chemotherapy together with allogeneic hematopoietic stem cell transplantation (alloHSCT) has improved the outcome of patients with Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL). Although to date, no study has shown alloHSCT to be inferior to chemotherapy plus TKIs in any subgroup of adult Ph+ ALL, there is some evidence suggesting no additional benefit of alloHSCT in patients with deep molecular responses to intensive chemotherapy with a second-generation, and especially, third-generation TKI. As none of these positive and negative studies are controlled, randomized trials are needed to fully define the role of alloHSCT in Ph+ ALL, especially in those with deep molecular response. However, if studies combining TKIs with new approaches such as immunotherapy lead to durable responses, alloHSCT in the first complete remission could be avoided in the near future in the majority of patients with Ph+ ALL