Ponatinib is an orally administered kinase inhibitor whose principal target is BCR::ABL1. It was developed to retain activity against BCR::ABL1 variants associated with resistance, including T315I.
Pharmacology
Ponatinib inhibits BCR::ABL1 and multiple additional kinases. Its pharmacologic activity affects signaling involved in malignant-cell proliferation.
Pharmacokinetics
Ponatinib is administered orally. Clinical pharmacology studies evaluated food effects, CYP3A-related interactions and absorption, distribution, metabolism and elimination characteristics.
The current prescribing information should be consulted for the precise pharmacokinetic parameters applicable to clinical use.
Pharmacodynamics
BCR::ABL1 inhibition reduces kinase signaling associated with abnormal leukemic-cell proliferation.
T315I
T315I is a clinically important BCR::ABL1 mutation because it can confer resistance to several earlier TKIs. Ponatinib has activity against T315I and is specifically incorporated into regulatory treatment indications for T315I-positive disease.
Clinical evidence
The original development program included a pivotal phase 2 study involving 449 patients with CML or Ph+ ALL who were resistant or intolerant to dasatinib or nilotinib or had T315I disease.
Current U.S. labeling also incorporates clinical evidence for newly diagnosed Ph+ ALL in combination with chemotherapy and defines response-based dose reduction in this setting.
Safety evidence
The clinical evidence must be interpreted alongside ponatinib’s substantial vascular and cardiovascular safety risks. The FDA boxed warning reflects arterial occlusive events, venous thromboembolism, heart failure and hepatotoxicity.
Evidence limitations
Clinical-trial outcomes describe study populations and cannot predict an individual patient’s response or risk.