Iguratimod versus salazosulfapyridine in rheumatoid arthritis patients with an inadequate response to methotrexate: Adjusted with propensity score matching.

This article compares the efficacy, retention rate, and safety of iguratimod (IGU) versus salazosulfapyridine (SASP) as add-on conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) for rheumatoid arthritis (RA) patients with an inadequate response (IR) to methotrexate (MTX). In a retrospective multicenter study of 108 Japanese RA patients matched by propensity scores, the MTX+IGU group showed significantly higher 24-month retention rates (67.8% vs. 38.5%) and greater clinical improvement in disease activity scores (DAS28-CRP) and European League Against Rheumatism (EULAR) response rates compared to the MTX+SASP group. Both treatments had comparable adverse event rates, though a greater decline in renal function (estimated glomerular filtration rate) was observed with IGU, indicating the need for renal monitoring. The study concludes that IGU is a promising add-on csDMARD for MTX-IR RA patients, but emphasizes the necessity for further prospective studies to confirm these findings and monitor safety.