Effectiveness and safety of filgotinib in rheumatoid arthritis patients: data from the GISEA registry

Objectives: The aim of this study was to evaluate the effectiveness and safety profile of filgotinib, a JAK1 preferential inhibitor, in rheumatoid arthritis (RA) patients included in Italian GISEA (Group for the Study of Early Arthritis) registry. Methods: Data from RA patients treated with filgotinib, recorded in the GISEA registry, were analysed. Disease activity scores and patient-reported outcomes (PROs) were assessed at baseline, as well as during 12-month follow-up. A difficult-to-treat (D2T) RA patient was defined according with EULAR criteria. Retention rate of filgotinib was estimated by the Kaplan-Meier method and factors influencing drug discontinuation were estimated by Cox regression models. Results: 246 RA patients (female 89%, 57.6±12.2 years old) started filgotinib, mostly as second (22%) or further (43.9%) b/tsDMARDs line of treatment. At 3 and 12 months, 18.8% and 27.5% of patients achieved Clinical Diseases Activity Index based remission and 30.1% and 37.7% obtained a visual analogue scale of pain ≤20 (all p<0.01 vs. baseline). Filgotinib survival rate was 84.5% at the 6-month and 75.8% at 12-month follow-up, and was comparable either in monotherapy or combination therapy, and irrespective of glucocorticoid intake. b/tsDMARD naive patients had the lowest hazard ratio (HR) of filgotinib discontinuation (HR 0.29, 95%CI 0.14-0.64), while D2T-RA the highest (HR 1.82, 95%CI 1.01-3.3). Eight patients (3.3%) discontinued filgotinib due to adverse events. Conclusions: In an Italian real-life setting, filgotinib is confirmed to be safe and with a good effectiveness profile both in monotherapy and without glucocorticoids.