Efficacy and Safety of Janus Kinase Inhibitors for the Treatment of Atopic Dermatitis: A Systematic Review and Meta-Analysis

<b><i>Background:</i></b> Current therapeutic options for atopic dermatitis (AD) are limited. Janus kinase (JAK) inhibitors may be viable alternatives. <b><i>Objectives:</i></b> To assess the efficacy and safety of JAK inhibitors for AD treatment. <b><i>Methods:</i></b> We searched PubMed, Embase, the Cochrane Controlled Register of Trials, Web of Science, Global Resource of Eczema Trials database, and ClinicalTrials.gov from inception to September 1, 2020. Randomized clinical trials (RCTs) comparing JAK inhibitors with placebo/vehicle treatment for AD patients were included. The primary study outcomes included (1) the change (%) from the Eczema Area and Severity Index (EASI) baseline expressed as weighted mean difference (WMD) and 95% confidence interval (95% CI), and (2) the Investigator’s Global Assessment (IGA) response and safety outcomes expressed as relative risk (RR) and 95% CI. <b><i>Results:</i></b> We included 14 RCTs published in 13 studies (3,822 patients). Treatment with JAK inhibitors significantly improved IGA response (RR 2.83, 95% CI 2.25–3.56, <i>p</i> &#x3c; 0.001) and EASI score (WMD –28.82, 95% CI –34.48 to −23.16, <i>p</i> &#x3c; 0.001). JAK inhibitor treatment achieved the largest improvement in both IGA response (RR 3.59, 95% CI 2.66–4.84, <i>p</i> &#x3c; 0.001) and EASI score (WMD –42.00, 95% CI –48.64 to −35.36, <i>p</i> &#x3c; 0.001) by week 4 of treatment. Topical JAK inhibitors were significantly more efficacious than oral inhibitors. Upadacitinib treatment for 4 weeks was most effective in reducing EASI score (WMD –53.92, 95% CI –69.26 to −38.58, <i>p</i> &#x3c; 0.001), while abrocitinib for 4 weeks led to the most effective IGA response (RR 5.47, 95% CI 2.74–10.93, <i>p</i> &#x3c; 0.001). There was no difference in the frequency of adverse events (AEs) leading to discontinuation; however, JAK inhibitors use, especially abrocitinib, led to a higher incidence of treatment-emergent AEs (RR 1.25, 95% CI 1.10–1.42, <i>p</i> = 0.001). <b><i>Conclusion:</i></b> Our results imply that JAK inhibitors are an effective and safe AD treatment. Nevertheless, further trials with longer duration and head-to-head comparisons of different JAK inhibitors are needed.