Bleeding risk with concurrent use of anticoagulants and ibrutinib: A population-based nested case-control study.

Data regarding the safety of co-administration of ibrutinib with anticoagulants in real-life settings are scarce. Using a nationwide database, we conducted a nested case-control study in a cohort of new users of ibrutinib to assess the risk of clinically relevant bleeding (CRB) associated with anticoagulation. Cases were patients with a diagnosis of CRB, defined as hospitalization with a diagnosis of bleeding. The date of CRB constituted the index date. Up to four controls were matched on sex, age at index date and duration of follow-up. The risk of CRB associated with anticoagulation in patients receiving ibrutinib was estimated using conditional logistic regression models, providing odds ratios (OR) adjusted for risk factors of bleeding. Among 614 cases and 2407 matched controls, the risk of CRB was significantly higher in patients receiving both ibrutinib and anticoagulants (adjusted OR [aOR] 2.54, confidence interval [CI] 95% [1.94; 3.32]). When considering anticoagulant class, aOR was 1.99 (CI 95% [1.19; 3.33]) for VKA, 2.48 (CI 95% [1.76; 3.47]) for direct oral anticoagulants and 3.40 (CI 95% [2.01; 5.75]) for parenteral anticoagulants. In conclusion, this study found a 2.5-fold increased risk of CRB in patients receiving both ibrutinib and anticoagulants in real-life settings, and similar aOR among oral anticoagulants.