How treatment with posttransplant maintenance tyrosine kinase inhibitors (TKIs) affects allogeneic hematopoietic stem cell transplantation for patients with high-risk Philadelphia chromosome-positive (Ph+) leukemia is not fully understood. Researchers, based at the Winship Cancer Institute, Emory University, Atlanta, sought to determine the effect of TKI therapy on this patient group.
The investigators followed the progress of 26 patients total (17 patients with Ph+ acute lymphoblastic leukemia and 9 patients with chronic myeloid leukemia) who received maintenance posttransplant therapy. The patients were treated with dasatinib, imatinib, nilotinib, or ponatinib, and treatment took place in the 10-year period from 2004 through 2014. TKI therapy was begun a median of 100 days following transplantation and the duration of therapy was 16 months (median).
TKI selection was determined according to estimated toxicities, pretransplantation response, and ABL1 domain mutations, if any. The median follow-up period was 3.6 years. The patient relapse-free survival rate was 61% after a 5-year period, and the overall survival rate was 78%. The 3 patients who subsequently experienced relapse were found to be disease-free after successful salvage treatment.
The research team concluded that TKI therapy following allogeneic hematopoietic stem cell transplantation may be beneficial, reducing the number of relapses for patients with advanced Ph+ leukemia.
1. DeFilipp Z, Langston A, Chen Z, et al. Does post-transplant maintenance therapy with tyrosine kinase inhibitors improve outcomes of patients with high-risk Philadelphia chromosome-positive leukemia? Clin Lymphoma Myeloma Leuk. 2016. doi: 10.1016/j.clml.2016.04.017. [Epub ahead of print]