Ponatinib-Blinatumomab or Imatinib-Chemotherapy for Adult Ph-Positive ALL

The outcome of Philadelphia-positive acute lymphoblastic leukemia (Ph-positive ALL) has greatly improved with the use of tyrosine kinase inhibitors and immunotherapy.

In this trial, we randomly assigned adult patients with Ph-positive ALL in a 2:1 ratio to receive ponatinib plus blinatumomab (intervention group) or imatinib plus chemotherapy (control group) as frontline treatment. A crossover to the intervention group was allowed for patients with persistence or reappearance of measurable residual disease in the control group. The primary end point was event-free survival.

A total of 236 patients underwent randomization: 158 to the intervention group and 78 to the control group. The median age of the patients was 55 years (range, 24 to 82). At a median follow-up of 23.7 months, the estimated 24-month event-free survival was 86% in the intervention group and 67% in the control group (P<0.001). Survival with no measurable residual disease was 68% and 42%, respectively. At the end of induction, a complete hematologic response was observed in 94% of the patients in the intervention group and in 79% of those in the control group. After blinatumomab consolidation, a molecular response was observed in 71% and 49% of the patients, respectively. After crossover to the intervention group, 20 of 31 patients (64%) had a molecular response. Overall survival was 90% in the intervention group and 85% in the control group. The cumulative incidence of relapse was 5% and 13%, respectively. As of this report, only 19% of the patients in the intervention group had undergone hematopoietic stem-cell transplantation after having had a first complete hematologic response.