Pooled Safety Analysis of Baricitinib in Adult Participants with Atopic Dermatitis in the Japanese Subpopulation from Six Randomized Clinical Trials

INTRODUCTION: Baricitinib is an oral selective Janus kinase (JAK)1/JAK2 inhibitor approved in Japan and the European Union for the treatment of atopic dermatitis (AD). The aim of this study is to report pooled safety data for baricitinib in the Japanese subpopulation of the clinical development program in moderate-to-severe AD. METHODS: This analysis included participant-level safety data from five double-blind, randomized clinical studies and one double-blind, randomized, long-term extension study, reported in three datasets for the Japanese subpopulation: (1) placebo-controlled, (2) baricitinib 2 mg and 4 mg extended (“2-mg—4-mg extended”), and (3) all baricitinib doses (“All-bari-AD”). The data cutoff was 13 December 2019. Safety outcomes included treatment-emergent adverse events, adverse events of special interest, and abnormal laboratory changes. Proportions of participants with events and incidence rates were calculated. RESULTS: Data were collected for 341 participants from Japan who received baricitinib for 371.7 participant-years (median duration 371.0 days). In the placebo-controlled dataset, the frequencies of serious infections and herpes zoster were low and similar between treatment groups, and the incidence of treatment-emergent infections, in particular herpes simplex, was higher in the baricitinib groups compared with the placebo group. No gastrointestinal perforations, tuberculosis, positively adjudicated cardiovascular events, deep vein thrombosis, or pulmonary embolism were reported with exposure up to 2 years in the All-bari-AD dataset. There were no deaths in the Japanese subpopulation. CONCLUSIONS: This integrated safety analysis in the subpopulation of Japanese participants is consistent with the established safety profile of baricitinib in the global study population with moderate-to-severe AD. CLINICALTRIALS.GOV IDENTIFIERS: NCT02576938, NCT03334396, NCT03334422, NCT03428100, NCT03733301, and NCT03334435.