Outcomes and patterns of relapse with ponatinib-based therapy in patients with chronic myeloid leukemia in myeloid blast phase.

We analyzed 76 patients who received a ponatinib-based regimen, either as monotherapy or in combination with chemotherapy, for chronic myeloid leukemia in myeloid blast phase (CML-MBP). The rate of morphological remission with or without count recovery (i.e. overall response rate [ORR]) was 49%. Patients who received a ponatinib-based regimen as their first therapy for CML-MBP had better ORR than those received ponatinib as salvage (60% versus 27%, respectively; p = 0.006). ORR was also higher with ponatinib combination therapy than monotherapy (54% versus 29%, respectively; p = 0.06). For the entire cohort, the median RFS and OS were 11.9 and 8.5 months, respectively. Responding patients who underwent allogeneic HSCT had superior outcomes to those who did not (2-year OS 79% versus 38%, respectively; p = 0.05). After ponatinib failure, outcomes were dismal (median OS: 3.9 months). Ponatinib-based regimens are effective in CML-MBP, especially when used as first therapy and in combination with chemotherapy, followed by HSCT.