Efficacy of nilotinib in a patient in non-optimal response after imatinib treatment but in reduced compliance to the new drug

We report a case of a patient with chronic myeloid leukemia in chronic phase who was treated with imatinib at standard dose from diagnosis to 18 months end point. He rapidly achieved a stable complete cytogenetic response (CCyR), but not a major molecular response (MMolR). According to European LeukemiaNet (ELN) recommendations, he was classified as a suboptimal patient. Since the treatment was fully tolerated by the patient, we tried an imatinib dose escalation in order to improve this result, obtaining only a transitory MMolR: BCR-ABL trascript level waved from 0,23 to 0,3% (BCR-ABL/ABL%). Therefore, we proposed a change of therapy. Due to his optimal compliance to imatinib and his wish of a future pregnancy, he refused the proposal. Unfortunately the pregnancy remained a desire, therefore, after 1 year of stable results (“near” MMolR), the patient switched to nilotinib at 400 mg/BID. After 3 months of treatment he achieved MMolR and after 6 months we could also document a complete molecular response (CMolR).