BTK inhibitors for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2): A systematic review

INTRODUCTION: The Bruton tyrosine kinase (BTK) regulates B cell and macrophage signaling, development, survival, and activation. Inhibiting BTK has been hypothesized to ameliorate lung injury in patients with severe COVID-19, however clinical outcome data is inconclusive. OBJECTIVE: To evaluate the clinical outcomes of BTK inhibitors (BTKinibs) in patients with COVID-19. EVIDENCE REVIEW: We searched PubMed, Embase, and Web of Science:Core on December 30, 2020. Clinical studies with at least 5 COVID-19 patients treated with BTKinibs were included. Case reports and reviews were excluded. FINDINGS: 125 articles were identified, 6 of which met inclusion criteria. The most common clinical outcomes measured were oxygen requirements (4/6) and hospitalization rate or duration (3/6). Three studies showed decreased oxygen requirements in patients who started or continued BTKinibs. All three studies that evaluated hospitalization rate or duration found favorable outcomes in those on BTKinibs. CONCLUSIONS AND RELEVANCE: BTKinib use was associated with decreased oxygen requirements and decreased hospitalization rates and duration.