Nilotinib therapy in chronic myelogenous leukemia

Imatinib mesylate (Gleevec®; Novartis, Basel, Switzerland) is a highly effective inhibitor of the deregulated kinase activity of BCR-ABL in chronic myelogenous leukemia (CML) and represents the current standard of care for patients with this disease. Mutations within the ABL kinase domain that interfere with drug binding have been identified as the main mechanism of resistance to imatinib. Currently, more than 50 different BCR-ABL mutants conferring varying degrees of resistance to tyrosine kinase inhibitors have been identified. Nilotinib (Tasigna®; Novartis) is a second-generation tyrosine kinase inhibitor with 30-fold higher potency against BCR-ABL kinase than imatinib. Notably, nilotinib is active against a wide range of imatinib-resistant or-intolerant patients, except for T315I. Results from the pivotal phase II studies of nilotinib for patients with CML after failure or intolerance to imatinib therapy indicate that nilotinib has a favorable toxicity profile and is highly efficacious in this setting. Studies exploring the efficacy of nilotinib as front-line therapy for patients with newly diagnosed CML are ongoing. Here, we review the preclinical and clinical development of nilotinib for the treatment of CML.