Nilotinib in imatinib-resistant CML and Philadelphia chromosome-positive ALL

Area of Science:

• Oncology
• Pharmacology
• Hematology

Background:

• Imatinib mesylate resistance is a challenge in chronic myelogenous leukemia (CML).
• Nilotinib (AMN107) is a novel BCR-ABL tyrosine kinase inhibitor demonstrating superior potency against CML cells compared to imatinib.
• Preclinical studies indicate nilotinib is 20-50 times more potent than imatinib.

Purpose of the Study:

• To evaluate the safety and efficacy of nilotinib in patients with imatinib-resistant chronic myelogenous leukemia (CML) and acute lymphoblastic leukemia (ALL).
• To determine the optimal dosage and tolerability of nilotinib through a phase 1 dose-escalation study.

Main Methods:

• A phase 1 dose-escalation study involved 119 patients with imatinib-resistant CML or ALL.
• Patients received oral nilotinib at various doses: 50 mg to 1200 mg once daily, and 400 mg or 600 mg twice daily.
• The study monitored patient responses and adverse events.

Main Results:

• Common adverse events included myelosuppression, transient indirect hyperbilirubinemia, and rashes.
• In patients with the blastic phase of CML, 13/33 achieved a hematologic response and 9/33 a cytogenetic response.
• In the accelerated phase, 33/46 had a hematologic response and 22/46 a cytogenetic response. 11/12 patients in the chronic phase achieved complete hematologic remission.

Conclusions:

• Nilotinib demonstrates significant activity in patients with imatinib-resistant CML.
• The drug exhibits a relatively favorable safety profile.
• Nilotinib represents a promising therapeutic option for CML patients who have developed resistance to imatinib.