Real-world study comparing the efficacy of Janus kinase inhibitors in patients with difficult-to-treat rheumatoid arthritis

Objective This study aimed to analyze the clinical efficacy of JAK inhibitors in difficult-to-treat rheumatoid arthritis (D2TRA) and non-D2TRA patients and evaluate the factors influencing their efficacy using real-world data. Method Here, 159 JAK inhibitor-treated patients with rheumatoid arthritis were categorized into D2TRA and non-D2TRA groups. Data including the Clinical Disease Activity Index (CDAI) at initiation and 6 months after drug administration, drug retention months, and reason for discontinuation due to toxic adverse events were collected. Results The retention rates at 6 months were 64.0% (D2TRA) and 78.4% (non-D2TRA) and were significantly different between the two groups (p = 0.030). The discontinuation rate owing to toxic adverse events significantly differed between the two groups (p = 0.030). The CDAI-low disease activity (LDA) rates differed significantly between the two groups (non-D2TRA, 62.3%; D2TRA, 34%; p < 0.001). CDAI-LDA achievement at 6 months after drug introduction was significantly associated with the number of times that biologic and/or targeted synthetic disease-modifying anti-rheumatic drugs were previously used and the CDAI at baseline in all patients treated with JAK inhibitors. However, no predictive factors were identified for D2TRA patients treated with JAK inhibitors. Conclusion Compared to non-D2TRA patients, D2TRA patients demonstrated significantly lower drug retention rates, CDAI-LDA achievement rates, and safety of JAK inhibitors. No significant predictive factor for CDAI-LDA achievement 6 months after drug introduction was detected in D2TRA patients. Key Points center dot The retention of JAK inhibitors were significantly lower for the treatment of D2TRA patients in comparison with non-D2TRA patients.center dot The efficacy and safety of JAK inhibitors were significantly lower for the treatment of D2TRA patients.center dot Number of previous uses of b/tsDMARDs and CDAI at baseline were identified as the predictive factors for resistance to CDAI-LDA achievement to JAK inhibitor treatment.center dot No significant predictive factor for CDAI-LDA achievement 6 months after drug introduction was detected in D2TRA patients.