Salvage and bridging to allogeneic hematopoietic cell transplantation with ponatinib in patients with relapsed or refractory Philadelphia chromosome-positive leukemia

A single-center retrospective study was performed with consecutive patients who received salvage therapy using ponatinib for the aim of allogeneic hematopoietic cell transplantation (HCT) for relapsed or refractory Ph-leukemia between January 2017 and July 2018. A total of ten patientsseven with Ph-acute lymphoblastic leukemia (ALL) and three with chronic phase (CP)/accelerated phase chronic myeloid leukemia (CML)were eligible. Eight patients had a history of a single tyrosine kinase inhibitor (TKI) use prior to ponatinib. Any mutation of the tyrosine kinase domain was detected in eight patients, including seven of T315I. The median dose of ponatinib was 15mg with a median duration of 7weeks (range 4-23weeks). The median duration from the start of ponatinib to HCT was 54days (range 35-175days). Hematological remission was obtained in five Ph-ALL patients. Maintenance therapy of ponatinib was applied to five patients. No vascular occlusion event has occurred over this series of treatments. Salvage therapy with low-dose ponatinib appears to be safe and effective in patients with relapsed or refractory Ph-leukemia, which may immediately bridge to HCT.