Pooled safety analysis of baricitinib in adult patients with atopic dermatitis from 8 randomized clinical trials

Background: Janus kinase (JAK) inhibition is a new mode of action in atopic dermatitis (AD); clarity about drug class safety considerations in the context of AD is important. Baricitinib, an oral, reversible, selective inhibitor of JAK1/JAK2, is in late-stage development for adult patients with moderate-to-severe AD. Objective: To report pooled safety data for baricitinib in patients with moderate-to-severe AD in the clinical development program including long-term extension (LTE) studies. Methods: This analysis included patient-level safety data from six double-blinded, randomized, placebo-controlled studies (one phase 2 and five phase 3), one double-blinded, randomized, LTE study and one open-label LTE study, reported in three data sets: placebo-controlled, 2-mg – 4-mg extended and All-bari AD. Safety outcomes include treatment-emergent adverse events, adverse events of special interest and abnormal laboratory changes. Proportions of patients with events and incidence rates were calculated. Results: Data were collected for 2531 patients who were given baricitinib for 2247 patient-years (median duration 310 days). The frequency of serious infections, opportunistic infections and conjunctival disorders was low and similar between treatment groups in the placebo-controlled period. The most common serious infections were eczema herpeticum [n = 11, incidence rates (IR) = 0.5], cellulitis (n = 6, IR = 0.3) and pneumonia (n = 3, IR = 0.1). There were four opportunistic infections (IR = 0.2). No malignancies, gastrointestinal perforations, positively adjudicated cardiovascular events or tuberculosis were reported in the placebo-controlled period in baricitinib-treated patients. Frequency of herpes simplex was higher in the 4-mg group (6.1%) vs. the 2-mg (3.6%) and placebo group (2.7%); IRs in the extended data set (2-mg IR = 9.6; 4-mg IR = 14.5) were lower vs. the placebo-controlled data set (2-mg IR = 12.4; 4-mg IR = 21.3). In the All-bari AD data set, there were two positively adjudicated major adverse cardiovascular events (2-mg group): two venous thrombosis events (4-mg group) and one death. Conclusion: This integrated safety analysis in patients with moderate-to-severe AD confirms the established safety profile of baricitinib.