Efficacy of nilotinib as third-line treatment in a patient with very late Chronic Myeloid Leukemia and a possibile cardiologic contraindication

We report a case of a patient with chronic myeloid leukemia who was treated with nilotinib after failure to imatinib and dasatinib. The patient, diagnosed in 1998, was cytogenetically resistant to imatinib. She was switched to dasatinib and achieved a major cytogenetic response, but 3 years later a mutant clone emerged responsible for cytogenetic relapse. The mutation we detected was V299L, that is resistant in vitro to dasatinib, while maintaining a good sensitivity to nilotinib. As the patient was not eligible for allotransplat, we decided to switch to nilotinib, despite a ECG abnormality (wandering pace-maker). After one-year treatment, the patient is in complete cytogenetic response with a low BCR-ABL/ABL transcript ratio. On mutational analysis, the V299L mutation has disappeared. Any cardiologic toxicity has not been observed so far. This case proves that ECG abnormalities do not represent an absolute contraindication to nilotinib and that nilotinib can be effective as third-line BCR-ABL inhibitor.