Iguratimod, a Synthetic Disease Modifying Anti-rheumatic Drug Inhibiting the Activation of NF-κB and Production of RANKL: Its Efficacy, Radiographic Changes, Safety and Predictors over Two Years' Treatment for Japanese Rheumatoid Arthritis Patients

Objective: To elucidate the clinical and radiographic outcomes for rheumatoid arthritis (RA) patients treated with a synthetic disease-modifying antirheumatic drug, iguratimod (IGU).

Methods: Clinical outcomes for 213 RA patients treated with 25 mg/day oral IGU or 50 mg/day after 4 weeks of 25 mg/day treatment for one day to 104 weeks were assessed.

Results: A total of 142 active RA patients (DAS28-ESR ≥3.2) treated for more than 12 weeks showed a significant reduction in both DAS and simplified disease activity index (SDAI) scores at week 4 (p < .001) to week 104. Good and moderate DAS responses were achieved in 54 (38%) and 66 (46%) patients, respectively. Total Genant-modified Sharp scores (GSS) of 31 patients at week 104 showed no progression (total GSS ≤0.84: the smallest detectable change) in 16 (52%) patients with a mean score reduction (95%CI) of -4.3 (-8.1∼-0.5) (p < .05). Predictors were an early response, moderate disease activity at baseline, and male gender. Eleven of the 213 patients had gastric and/or duodenal ulcer. A peculiar haemorrhage was seen in two patients treated concomitantly with IGU and warfarin potassium.

Conclusion: IGU treatment shows an early and sustained efficacy. Radiographically, no progression of GSS was evident in 16 (52%) patients at week 104. Gastric bleeding or gastric perforation warrants careful attention, especially in patients with concomitant use of both a non-steroidal anti-inflammatory drug and oral prednisolone.