Response Rate Similar Between Low- and Standard-dose Ponatinib

Response with low-dose ponatinib is similar to that of standard-dose ponatinib among patients with refractory chronic myeloid leukemia (CML) or Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL), according to preliminary real-world data presented at the 2016 Society of Hematologic Oncology Annual Meeting.¹

Ponatinib is a kinase inhibitor approved for kinase inhibitor indicated for the treatment of adult patients with T315I-positive CML or T315I-positive Ph+ ALL, and adult patients with chronic phase, accelerated phase, or blast phase CML or Ph+ ALL for whom no other tyrosine kinase inhibitor therapy is indicated. The recommended starting dose is 45 mg once daily, but about one-fourth of ponatinib-treated patients experience vascular occlusion at this dose.

Researchers evaluated the effectiveness and safety of low-dose ponatinib using chart data from patients with CML who received an average dose no greater than 30 mg/day.

There was no significant difference in median time on therapy (P = .336) or the rate of dose reductions (P = .411), which were common, between patients treated with low-dose ponatinib and those who received standard-dose ponatinib, defined as greater than 30 mg/day.

There were no significant differences in major molecular response or better (P = .344), major cytogenetic response or better (P = .625), or major hematologic response or better (P = .331) between the 2 groups.

Researchers observed a trend toward more arterial occlusive events with lower average doses of ponatinib (P = .076), suggesting that vascular occlusion may be more strongly associated with risk rather than dose.

There was no difference in the rate of other adverse events of interest in this real-world population.

Reference

1. Mauro M, McGarry L, Inguilizian A, du Moulin R, Huang H. A chart review of lower dosing of ponatinib in patients with chronic myeloid leukemia (CML): Preliminary findings. Poster presented at: 2016 Society of Hematologic Oncology Annual Meeting; September 7-10, 2016; Houston, TX.