Rapid and sustained molecular response to nilotinib in a patient with sub-optimal response to imatinib

We describe here the case of a 40-years-old woman diagnosed as having chronic phase chronic myeloid leukemia and treated with standard dose of imatinib; the patient obtained the complete cytogenetic remission in 7 months, but she failed to achieve major molecular response (MMolR) after more than18 months of imatinib therapy. Sub-optimal response, defined according European LeukemiaNet guidelines, persisted despite of increasing imatinib dose to 600 mg daily. No BCR-ABL mutations were detected. Three months after switching to nilotinib 800 mg bid, the patient obtained MMolR. She experienced any toxicities due to nilotinib. We speculate about use of nilotinib in patients classified as sub-optimal at 18 months from imatinib.