Switching to biological DMARDs versus cycling among JAK inhibitors in patients with rheumatoid arthritis and with inadequate response to JAK inhibitors: from FIRST registry.

Objectives: This study aimed to identify characteristics of patients with rheumatoid arthritis (RA) with an inadequate response to Janus kinase inhibitors (JAKi-IR) and evaluate the efficacy and safety of subsequent treatments.

Methods: This study included 434 patients with RA who started JAKi treatment. JAKi-IR patients were those who switched to another drug due to inadequate response or did not reach low disease activity within 26 weeks of beginning JAKi. The efficacy and safety of switched biological disease-modifying anti-rheumatic drugs (bDMARDs) or cycled targeted synthetic disease-modifying anti-rheumatic drugs were analysed 26 weeks after switching treatment in JAKi-IR patients.

Results: Patients with JAKi-IR RA accounted for 31.8% (n=138/434). Multiple logistic regression identified factors contributing to JAKi-IR, such as the prior use of multiple ineffective bDMARDs and suboptimal JAKi dosing. There were no differences in patient background when comparing patients with RA with JAKi-IR who cycled to another JAKi (n=31) versus those who switched to bDMARDs (n=45). Among those cycling to another JAKi, the Clinical Disease Activity Index (CDAI) scores improved by week 26, with higher remission rates, while retention and adverse events remained similar. Trajectory analysis identified three CDAI response patterns, with the 'treatment response' group showing rapid and sustained improvement when cycling to another JAKi. Multiple logistic regression in this group identified another JAKi cycle as the critical factor for the treatment response.

Conclusions: Cycling JAKis is more effective than switching to bDMARDs in JAKi-IR RA, with no differences in safety or retention. This study suggests that cycling to another JAKi may be appropriate for patients with RA with JAKi-IR.