Bruton tyrosine kinase inhibitor monotherapy in B-cell lymphoma and risk of infection: A systematic review and meta-analysis of randomized controlled trials

Bruton's tyrosine kinase (BTK) inhibitors are important therapeutic advances with promising efficacy outcomes in the treatment of patients with chronic lymphocytic leukemia and other B-cell lymphoma subtypes. However, the utility of BTK inhibitors can be limited by adverse events such as infections. In this systematic review and meta-analysis, we aim to determine the risk of various infections associated with BTK inhibitor monotherapy in B-cell lymphoma patients. A comprehensive search was conducted in MEDLINE/PubMed, Embase, and Web of Science databases from their inception until October 2023. ClinicalTrials.gov, bibliographies, and relevant conference abstracts were also searched for additional records. Randomized controlled trials that included any B-cell lymphoma patients treated with BTK inhibitor monotherapy and reported infection were included. Meta-analysis was performed to calculate risk ratio (RR) using a random-effects model in R Statistical Software, version 4.3.2. Of 3292 studies retrieved, we included 12 studies in this systematic review and meta-analysis. The median age of patients across the study arms ranged between 64 and 73 years. The overall pooled RR for any grade upper respiratory tract infections (URTI) associated with BTK inhibitor treatment was 1.55 (95% Confidence Interval (CI) 1.22–1.97). The RR of grade ≥3 URTI was reported in 14 out of 1046 patients, yielding an RR of 1.46 (95% CI 0.61–3.54), which was not statistically significant. The pooled RR of any grade pneumonia was 1.20 (95% CI 0.68–2.10) and grade ≥3 pneumonia was 1.12 (95% CI 0.67–1.85), both of which were not statistically significant. Patients with B-cell lymphoma who are undergoing BTK inhibitor monotherapy face an elevated risk of developing URTI. Clinicians prescribing BTK inhibitors should be aware of the potential infectious events that may occur. Close monitoring and the implementation of effective prophylactic measures are essential for managing these patients.