Efficacy and safety of Janus kinase inhibitors in patients with difficult-to-treat rheumatoid arthritis.

Objectives: This study evaluated the effectiveness of Janus kinase inhibitors (JAKi) in patients with difficult-to-treat rheumatoid arthritis (D2T RA).

Methods: This study included 220 patients with RA who were treated with JAKi. Sixty-two patients were naïve to biological disease-modifying anti-rheumatic drugs (bDMARDs)/JAKi (1st group), 57 patients were failure to one bDMARDs/JAKi (2nd group), and 101 patients were failure to ≥ 2 bDMARDs/JAKi. Of these 101 patients, 25 did not meet the D2T RA criteria (non-D2T RA group) and 76 met the D2T RA criteria (D2T RA group).

Results: : DAS28-ESR was improved in all groups at 24 weeks (1st: p<0.01, 2nd: p<0.01, non-D2T RA: p=0.01, D2TRA: p=0.02), and improvement ratio of DAS28-ESR was not different between DT2RA group and 2nd (p=0.73) or non-D2T RA group (p=0.68). Glucocorticoid use (odds ratios: 8.67; 95% CI: 1.23-60.90; P=0.03) and number of past bDMARD/JAKi uses ≥ 3 (odds ratios: 10.55; 95% CI: 1.39-80.30; P=0.02) were risk factors for DAS28-ESR ≥ 3.2 at 24 weeks in the D2T RA group.

Conclusions: Clinical efficacy of JAKi in D2T RA group did not differ from that in 2nd and non-D2T RA groups. Glucocorticoid use and multiple bDMARD/JAKi failure were poor prognostic factors for D2T RA.