Long-Term Clinical Outcomes of the Patients with Chronic Myeloid Leukemia Treated with Nilotinib as the 1st-Line Tyrosine Kinases Inhibitor at the Kindai university hospital

Background: Nilotinib has been shown to be a more potent tyrosine kinase inhibitor of BCR::ABL1 than imatinib. We evaluated long-term efficacy and safety based on the 7-year follow-up data in patients with newly diagnosed chronic myeloid leukemia (CML) who were treated with nilotinib as the 1st-line therapy (1L-NIL) at the Kindai university hospital. Methods: In this single-center, observational study, we enrolled patients with newly diagnosed CML in chronic phase (CML-CP) who received 1L-NIL since December 2010, when nilotinib received regulatory approval for CML-CP in Japan. The primary endpoint was overall survival (OS) of the 1L-NIL patients. In addition, we analyzed molecular responses and safety profiles as the key secondary endpoints. Results: The median observation period was 6.8 (range: 1.2-12.3) years. The estimated OS and progression-free survival rates of the 1L-NIL patients (n=25) were both 95.5%. By 18 months, the cumulative achievement rates of major molecular response (MMR) and MR4.5 were 81.3% and 25.0%, respectively. Adverse events (AEs) occurred in 21 of 23 patients (91.3%) with Grade ≥3 in 8 of 23 patients (34.8%). We observed no unexpected serious AEs in this research. Conclusions: Our data showed that the efficacy of nilotinib persisted over the 7-year follow-up and long-term administration of nilotinib was not associated with unacceptable late toxic effects at the Kindai university hospital.