Comparison of JAK inhibitors and biologics with respect to pain reduction in patients with rheumatoid arthritis: data from the KOBIO registry

Background/Aims: To compare the pain-reducing efficacy of Janus kinase inhibitors (JAKis) and biologic disease-modifying antirheumatic drugs (bDMARDs) in patients with rheumatoid arthritis (RA). Methods: Patients with RA enrolled in the Korean College of Rheumatology Biologics and Targeted Therapy (KOBIO) registry were grouped according to use of JAKis, TNFis, and non-TNFi bDMARDs. The primary outcome was to compare the changes in pain on a numeric rating scale (NRS, range 0-10) between enrolment and first follow-up. Logistic regression analysis was performed to identify the factors associated with a low pain NRS score (< 2) and retention at the 1-year follow-up. Results: The analysis included 2,415 patients with RA in the JAKis (n = 422), TNFis (n = 1,148), and non-TNFi bDMARDs groups (n = 845). The change in pain NRS was significantly greater in the JAKis group than in the TNFis group (2.8 ± 2.5 vs. 2.3 ± 2.9, respectively; p < 0.01). The adjusted mean additional pain reduction was significantly greater in the JAKis than in the TNFis group (-0.42, 95% confidence interval [CI]: -0.73 to -0.10). The adjusted odds ratio (OR) for achieving a pain NRS score < 2 with initial drug retention at 1 year follow-up was significantly lower in the TNFis (OR = 0.515; 95% CI: 0.406-0.652) and non-TNFi bDMARDs (OR = 0.586; 95% CI: 0.458-0.751) groups than in the JAKis group. Conclusions: Among patients who achieved treatment response and remained on therapy, JAKis were associated with greater improvement in pain control than TNFis.