Comparable Clinical Effectiveness of Baricitinib and Filgotinib in Patients With Rheumatoid Arthritis

AIM: To compare the clinical effectiveness of baricitinib and filgotinib in the treatment of rheumatoid arthritis (RA). METHODS: This retrospective study included 101 and 103 consecutive patients treated with baricitinib and filgotinib, respectively, between 2020 and 2023. Drug retention was analyzed using Kaplan-Meier curves, with the log-rank test for between-group comparisons. Differences in Clinical Disease Activity Index (CDAI) score from baseline were assessed using paired t-tests, and generalized estimating equations were used to compare the treatment groups. RESULTS: Baseline characteristics were similar between the baricitinib and filgotinib groups. Drug retention rates due to ineffectiveness or adverse events did not differ significantly between the two groups. In the baricitinib group, the estimated mean CDAI score significantly decreased from 17.8 at baseline to 9.1 at 4 weeks, 6.6 at 12 weeks, and 6.3 at 24 weeks (p < 0.001 for all comparisons). In the filgotinib group, the estimated mean CDAI score significantly decreased from 16.5 at baseline to 7.8 at 4 weeks, 6.2 at 12 weeks, and 6.1 at 24 weeks (p < 0.001 for all comparisons). No significant differences were observed between the two groups in CDAI score at any time point evaluated, or in the proportion of patients who achieved CDAI remission (CDAI ≤ 2.8) at baseline (7% vs. 5%) and after 4 (23% vs. 21%), 12 (33% vs. 33%), and 24 weeks (33% vs. 37%). CONCLUSION: Baricitinib and filgotinib demonstrated comparable drug retention rates and effectiveness in reducing disease activity among patients with RA over a 24-week follow-up period.