Preliminary results from an ongoing phase 1 dose-escalation study of the multikinase, pan–BCR-ABL inhibitor ponatinib (AP24534) showed antileukemic activity in patients with refractory CML, including patients with the T315I mutation.61 Phase 1 and 2 trials of ponatinib are ongoing in patients with refractory CML and acute lymphoblastic leukemia. Here, BCR is linked to chronic myelogenous leukemia, BCR-ABL1 positive.