Impact of prophylactic post-transplant ponatinib administration on outcomes in patients with Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ALL).

Abstract Background The objective of our study was to evaluate the impact of ponatinib administration as maintenance therapy on outcomes after allogeneic hematopoietic stem cell transplantation in patients with Philadelphia chromosome-positive acute lymphoblastic leukemia. Patients and Methods We retrospectively analyzed 34 consecutive patients at our institution between January 2008 and June 2019. We administered post-transplant TKI preemptively before December 2017. Thereafter, we initiated the prophylactic use of post-transplant ponatinib. The initial ponatinib dose was 15mg daily. Ponatinib plasma trough levels were measured using the liquid chromatography-tandem mass spectrometry method on and after day 8 following the first administration Results Nine patients received ponatinib maintenance. The two-year overall survival and leukemia-free survival in the ponatinib maintenance group tended to be better than that in the non-ponatinib group (100% vs. 70.5%, P = 0.10; 100% vs. 50.8%, P = 0.02, respectively). In the first 7 consecutive patients out of 9, the median plasma concentration following ponatinib administration (15 mg daily) was 15.6 ng/ml (range, 4.8-23.3). Although the treatment schedule in one patient was altered due to adverse effects (elevation of serum amylase and neutropenia), ponatinib administration to all our patients was continued, except in one patient with molecular relapse. One patient developed a transient elevation of serum lipase, No patient presented any arterial occlusive events Conclusion Our results indicate that the strategy of ponatinib maintenance following allo-HCT is safe, efficacious, and promising.