A Drug-Drug Interaction Study Of Ibrutinib With Moderate And Strong Cyp3a Inhibitors In Patients With B-Cell Malignancy

Background:Ibrutinib, a potent inhibitor of Bruton’s tyrosine kinase, is indicated for the treatment of mantle cell lymphoma, chronic lymphocytic leukemia/small lymphocytic lymphoma (including 17p deletion), and Waldenström’s macroglobulinemia. Because ibrutinib is extensively cleared by cytochrome P450 (CYP) 3A4, concomitant treatment with CYP3A inhibitors has been shown to increase ibrutinib exposure in healthy adults. However, sparse PK data from uncontrolled phase 2 studies with moderate CYP3A inhibitors showed a lower magnitude of drug-drug interactions (DDI) than observed in studies with healthy subjects or in silico simulations under nonfasted conditions (data on file). This phase 1 study was conducted to evaluate potential DDIs between ibrutinib and CYP3A inhibitors in patients with B-cell malignancies and to confirm recommended dose adjustments.