Patterns of use and safety of ibrutinib in real-life practice

Abstract

Aims: To provide real-life data on patterns of use and safety of ibrutinib. Methods: A cohort study including all patients initiating ibrutinib between 21 November 2014 and 21 November 2018, and followed for 1 year was conducted. Patient characteristics, ibrutinib use and adverse drug reactions (ADRs) were collected from medical records. Kaplan–Meier analysis estimated the probability of developing ibrutinib-associated serious ADRs (SADRs) with a 95% confidence interval (CI). A Cox proportional hazards model was used to investigate factors associated with SADR occurrence. Results: In total, 102 patients were included in the study. The median age was 70.3 years (interquartile range 64.7–75.6), the male/female gender ratio was 2.9. Almost half the patients (47.1%) were prescribed ibrutinib for chronic lymphocytic leukaemia (CLL). Forty-three patients (42.1%) permanently discontinued ibrutinib in the first year, mostly for progression (51.2%) or ADRs (32.6%). Forty-eight patients (47.1%) experienced at least one ibrutinib-associated SADR. Haematological, infectious and vascular disorders were the most frequent SADRs. The probability of developing ibrutinib-associated SADR was 35.1% (95% CI 26.3–45.7%) at 3 months, 44.8% (35.2%; 55.8%) at 6 months and 54.3% (44.0%; 65.2%) at 12 months. Age ≥80 years (hazard ratio [HR] 2.03; 95% CI 1.02–4.05) and CLL (HR 1.81; 95% CI 1.01–3.25) were significantly associated with a higher risk of SADR occurrence. Conclusion: This study found a high cumulative incidence of ibrutinib-associated SADRs within the first year of treatment. In view of the risk of SADR, patients aged ≥80 years or treated for CLL deserve special attention.