Ponatinib is an oral tyrosine kinase inhibitor (TKI). Its principal therapeutic target is BCR::ABL1, an abnormal kinase produced by the Philadelphia chromosome-associated genetic rearrangement in CML and Ph+ ALL.
BCR::ABL1 sends signals that promote abnormal proliferation and survival of leukemic cells. By inhibiting this kinase, ponatinib interferes with signaling that supports leukemia-cell growth.
The T315I mutation
One of ponatinib’s clinically important characteristics is activity against T315I-mutated BCR::ABL1. This mutation can interfere with the activity of several earlier BCR::ABL1 inhibitors.
Ponatinib was specifically designed as a potent BCR::ABL1 inhibitor capable of maintaining activity against resistant kinase forms, including T315I.
Beyond BCR::ABL1
Ponatinib also interacts with additional kinase targets. Its broader kinase activity contributes to its pharmacologic profile but can also affect normal biological processes.
This broader activity helps explain why ponatinib can cause adverse effects involving the cardiovascular system, liver, pancreas, blood counts and other organs.
Simple explanation
In simple terms, some leukemia cells depend on an abnormal molecular signal called BCR::ABL1. Ponatinib blocks that signal, which can limit the growth and survival of leukemia cells.
The treatment is not appropriate for every patient with leukemia. The disease subtype, previous treatment, mutation status and applicable regulatory indication all matter.