Nilotinib in Imatinib-Resistant CML and Philadelphia Chromosome–Positive ALL

Resistance to imatinib mesylate can occur in chronic myelogenous leukemia (CML). Preclinical in vitro studies have shown that nilotinib (AMN107), a new BCR-ABL tyrosine kinase inhibitor, is more potent than imatinib against CML cells by a factor of 20 to 50.

In a phase 1 dose-escalation study, we assigned 119 patients with imatinib-resistant CML or acute lymphoblastic leukemia (ALL) to receive nilotinib orally at doses of 50 mg, 100 mg, 200 mg, 400 mg, 600 mg, 800 mg, and 1200 mg once daily and at 400 mg and 600 mg twice daily.