Filgotinib Effectiveness in Rheumatoid Arthritis: Observational Analysis of a Large Multicenter Cohort

The efficacy and safety of filgotinib (FIL) for the treatment of patients with rheumatoid arthritis (RA) have been evaluated in a number of randomized controlled trials. However, there is a scarcity of real-world studies evaluating the effectiveness, persistence, tolerability, and safety of FIL in everyday clinical practice. This study aimed to assess the effectiveness and retention rate of FIL in a real-world cohort of patients with RA.

A multicenter retrospective cohort study of patients with RA treated with FIL was conducted in 27 Italian tertiary referral rheumatology centers. The drug retention rate (DRR) was estimated by the Kaplan-Meier method, while multivariate Cox regression was used to detect potential factors affecting drug survival and persistence in therapy. Disease activity score (DAS28-CRP) was assessed at baseline and after 6 and 12 months.

We enrolled 204 patients (80% female). The DRR of FIL was 90.2% (95% confidence interval (CI) 86-94.6%), 75.1% (95% CI 68.5-82.4%), and 64.7% (95% CI 56.3-74.3%) at months 6, 12, and 18, respectively. The DRR was negatively associated with the line of treatment and the presence of rheumatoid factor. Effectiveness was evaluated as DAS28-CRP response. At 6 months, DAS28-CRP remission was observed in 65 (36.1%) patients, and remission or low disease activity in 98 (54.4%). At 12 months, DAS28-CRP remission was observed in 64 (50.0%) patients, and remission or low disease activity in 81 (63.2%).

This analysis of real-world patients with RA demonstrated the effectiveness of FIL with a good DAS28-CRP response and high DRR at follow-up.