Efficacy and safety of baricitinib in 446 patients with rheumatoid arthritis: a real-life multicentre study

Objectives: Baricitinib, an oral Janus kinase (JAK) 1-2 inhibitor, is currently used along biologic DMARDs (bDMARDs) after the failure of methotrexate (MTX) in rheumatoid arthritis (RA). We investigated the efficacy and safety of baricitinib in real life. Methods: We prospectively enrolled 446 RA patients treated with baricitinib from 11 Italian centres. Patients were evaluated at baseline and after 3, 6, and 12 months. They were arrayed based on previous treatments as bDMARD-naïve and bDMARD-insufficient responders (IR) after the failure or intolerance to bDMARDs. A sub-analysis differentiated the effects of methotrexate (MTX) and the use of oral glucocorticoids (OGC). Results: Our cohort included 150 (34%) bDMARD-naïve and 296 (66%) bDMARD-IR patients, with 217 (49%) using baricitinib as monotherapy. Considering DAS-28-CRP as the primary outcome, at 3 and 6 months, 114/314 (36%) and 149/289 (51.6%) patients achieved remission, while those in low disease activity (LDA) were 62/314 (20%) and 46/289 (15.9%), respectively; finally at 12 months 81/126 (64%) were in remission and 21/126 (17%) in LDA. At all-timepoints up to 12 months, bDMARDs-naïve patients demonstrated a better clinical response, independently of MTX. A significant reduction in the OGC dose was observed at 3 and 12 months in all groups. The serum positivity for both rheumatoid factors (RF) and anti-citrullinated protein antibodies (ACPA) conferred a lower risk of stopping baricitinib due to inefficacy. Fifty-eight (13%) patients discontinued baricitinib due to adverse events, including thrombotic events and herpes zoster reactivation. Conclusions: Real-life data confirm the efficacy and safety profiles of baricitinib in patients with RA and provide evidence that drug survival is higher in bDMARDs-naïve and seropositive patients.