Italian Real-World Analysis of a Tyrosine Kinase Inhibitor Administration as First- or Second-Line of Therapy in Patients with Chronic Myeloid Leukemia

Purpose: To date, litte evidence is reported about the real-life dosage of tyrosine kinase inhibitors prescribed in Italy. The present observational retrospective study aimed to evaluate the mean daily dose of nilotinib prescribed as first- and second-line therapy among patients suffering from chronic myeloid leukemia (CML) in settings of clinical practice in Italy.

Patients and methods: Data were obtained from the administrative databases of a sample of Italian entities. All adult patients prescribed nilotinib were included from January 2013 to December 2016 if they were using it as first-line and from January 2015 to December 2018 as second-line therapy. The mean daily dose was calculated considering the dosage between first and last nilotinib prescription date or last BCR/ABL test date.

Results: Among CML patients treated with nilotinib as first-line (N=87), the mean daily dose of nilotinib was 500.5 mg during a mean treatment duration of 798.9 days and of 498.54 mg considering the last determination of BCR/ABL test (mean duration of 811 days). A total of 103 CML patients were prescribed nilotinib as second-line therapy; of them, 80.6% had previously received imatinib, 17.5% dasatinib. The mean daily dose of nilotinib was found to be 566.3 mg with a mean time duration of 302.8 days, while when the last BCR/ABL test was taken into account (mean duration of 323.1 days), a mean daily dose of 565.2 mg was detected.

Conclusion: The study reported on the real-world dosage pattern of a TKI for CML management. Our results compared with the dosage of nilotinib reported in datasheet (600 mg and 800 mg for first- and second-line, respectively) showed a trend of mean daily dose prescribed in clinical practice settings lower than the dosage currently indicated.