Efficacy and safety of switching Jak inhibitors in rheumatoid arthritis: an observational study

Objective. Different Jak inhibitors (jakinibs) have shown efficacy in rheumatoid arthritis (RA), but in a significant proportion of patients, an insufficient response leads to therapy withdrawal. We describe the efficacy and safety of a second jakinib in patients stopping the first due to insufficient response or side effects. Methods. This is an observational retrospective multicentric study of 31 patients with RA sequentially treated with baricitinib or tofacitinib in any order in clinical practice in ten medical centres in Spain. Results. We identified 31 patients, sequentially treated with both jakinibs. An equal proportion had received tofacitinib or baricitinib first. Most patients (87%) had previously received one or several bDMARD, median 4 (2-5). Median survival for the first jakinib was 5 (3-8) months, and the reasons for withdrawal were inefficacy in 61% and adverse effects in 39%. Most patients (23/31, 74%) maintained the response to the second jakinib after a mean follow-up of 19.5 (12-24) months. In all 8 patients who discontinued the second jakinib, the reason was inefficacy. The treatment suspension rate was similar among patients that had discontinued the first jakinib for inefficacy (26%) or for adverse effects (25%). Conclusion. Therapy of RA with a second jakinib seems a safe and efficacious option after discontinuation of the first, either for inefficacy or for side effects.