Frontline Nilotinib Versus Dasatinib in Newly Diagnosed Chronic Phase Chronic Myeloid Leukemia: A Propensity Score Analysis Based on Agenzia Italiana del Farmaco Monitoring Registries.

BACKGROUND: Time to treatment discontinuation (TTD) in chronic phase chronic myeloid leukemia (CML) adult Italian patients who started frontline dasatinib or nilotinib recorded in the Italian medicines agency (AIFA) monitoring registries, was explored. MATERIAL AND METHODS: Median TTD and follow-up were obtained using the Kaplan-Meier and Reverse Kaplan-Meier respectively. The methodology is based on the use of an Inverse Probability Treatment Weighting (IPTW) procedure to estimate propensity scores from the gradient boosting machine algorithm (gbm) model and obtain the corresponding weights. RESULTS: Overall, 1526 patients were analyzed (628 treated with dasatinib and 898 with nilotinib); baseline results, in the dasatinib and in the nilotinib cohorts, show percentage of males of 56.7% and 55.8% and a median age of 57.3 and 51.9 years respectively. After a median follow-up of 4.9 years and post-adjustment, TTD was 53.5 months with dasatinib and 70.5 with nilotinib (HR 0.61, 95% CI 0.54-0.69, p<0.0001). The probability of treatment persistence at 24 and 48 months with nilotinib was 0.79 (0.77-0.82) and 0.68 (0.65-0.72), respectively, and with dasatinib was 0.73 (0.70-0.77) and 0.55 (0.51-0.60), respectively. CONCLUSION: The results showed a longer treatment persistence with frontline nilotinib, to be considered for a planned discontinuation.