Results of the Simultaneous Combination of Ponatinib and Blinatumomab in Philadelphia Chromosome-Positive ALL

Abstract

<i>Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in</i> JCO <i>or elsewhere, for which the primary end point has already been reported.</i>In this analysis, we update our experience with the chemotherapy-free regimen of blinatumomab and ponatinib in 60 patients with newly diagnosed Philadelphia chromosome (Ph)-positive ALL. At a median follow-up of 24 months, the complete molecular response rate by reverse transcriptase-polymerase chain reaction was 83% (67% at the end of course one), and the rate of measurable residual disease negativity by next-generation clono-sequencing was 98% (45% at the end of course one). Only two patients underwent hematopoietic stem cell transplantation (HSCT). Seven patients relapsed: two with systemic disease, four with isolated CNS relapse, and one with extramedullary Ph-negative, CRLF2-positive pre-B ALL. The estimated 3-year overall survival rate was 91% and event-free survival rate was 77%. Three patients discontinued blinatumomab because of adverse events (related, n = 1; unrelated, n = 2) and nine discontinued ponatinib because of cerebrovascular ischemia, coronary artery stenosis, persistent rash, elevated liver function tests with drug-induced fatty liver, atrial thrombus, severe arterial occlusive disease of lower extremities, pleuro-pericardial effusion, and debilitation. In conclusion, the simultaneous combination of ponatinib and blinatumomab is a highly effective and relatively safe nonchemotherapy regimen. This regimen also reduces the need for intensive chemotherapy and HSCT in first remission in the majority of patients.