A Real-world Meta-analysis Study of Disease Severity in European Patients Who Received Baricitinib for Atopic Dermatitis: Data from BioDay, SCRATCH and TREATgermany.

Clinical trials have demonstrated the effectiveness of baricitinib, an oral selective Janus kinase 1/2 inhibitor, for patients with moderate-severe atopic dermatitis, but data from real-world practice are limited. This non-interventional cohort study evaluated clinician- and patient-reported disease severity over 16 weeks using 3 national atopic dermatitis registries: BioDay (Netherlands), SCRATCH (Denmark) and TREATgermany (Germany). Absolute scores for Eczema Area and Severity Index (EASI) and itch Numerical Rating Scale (Itch-NRS) were assessed at baseline and follow-up (Week 13/16) for each registry and for the overall pooled cohort. Descriptive analyses, generalized linear mixed modelling and meta-analysis approaches were applied to complete-case and multiply-imputed datasets. In total, 264 patients (89 BioDay, 117 SCRATCH, 58 TREATgermany) were included. Results showed improvements in EASI, with 58%, 68% and 62% achieving EASI≤7 at Week 13/16 in BioDay, SCRATCH and TREATgermany, respectively. In the pooled cohort, the proportion was 62% (95% CI: 50-73%). The pooled mean EASI change was -7.8 [14.4,-1.1]. Effectiveness was generally observed in both biologic-naïve and -experienced patients. Notable heterogeneity was observed, particularly for Itch-NRS, with the proportion achieving NRS≤4 ranging from 20% (BioDay) to 71% (TREATgermany). These real-world findings support the effectiveness of baricitinib while also highlighting variability in patient outcomes.