Background/Purpose:

Iguratimod is a new small-molecular drug for rheumatoid arthritis (RA), which was approved on June, 2012 in Japan. The agent inhibits the production of immunoglobulins and various inflammatory cytokines (interleukin-1, -6 and -8 and TNF), and exerts anabolic effects on bone metabolism by stimulating osteoblastic differentiation and inhibiting osteoclastogenesis in mice through inhibiting the nuclear transcription factor NF-κB, but not its inhibitor, IκBα. In addition this agent is very cheap (1.5$/25 mg tablet) , so 50 mg/day iguratimod therapy costs only 3$/day. A few clinical efficacies have been reported, while radiographic efficacy have never reported. In this study, We evaluate the clinical and radiographic efficacy of iguratimod for RA patients. 

Methods:

62 patients who were administered iguratimod at a dosage of 25mg qd during the first month, then 50mg qd thereafter, and followed up for 24 weeks were enrolled. Efficacy was evaluated by composite measures such as DAS28, SDAI, HAQ-DI and modified Total Sharp Score (mTSS), and safety was evaluated by adverse events.

Results: The mean age was 61.3 years and 75.8% of patients were female. MTX was used in 46.8%, the average dose was 8.6±2.9 mg/week. LOCF analysis revealed that DAS28-ESR and SDAI decreased significantly from 4.49±1.33 to 3.12±1.08 and from 18.5±10.9 to 8.3±6.34 in 52 weeks respectively (P<0.01). Remission and LDA rate in DAS28-ESR were 29.0% and 24.2%.  HAQ-DI score also decreased from 1.2±0.8 to 0.85±0.79. The percentage of patients with no radiographic progression(ΔmTSS <0.5) was 56.8%, while that of rapid radiographic progression(ΔTSS >5) was 13.5%. The mean estimated yearly progression was 9.9 ± 15.6 at baseline. After 52 weeks of IGU treatment, the mean change was significantly reduced to 1.2 ± 2.5(P<0.01).The difference between the efficacy of igurarimod with and without MTX was not significant. 35.5%(n=22) of the patients discontinued iguratimod within 52 weeks. The reason of cessation consisted of adverse events (21.0%) and lack of efficacy (6.5%). Adverse events were digestive symptom (n=6), liver dysfunction (n=4), nasal hemorrhage (n=2) and so on. There’s no severe adverse event. 

Conclusion:

IGU reduced disease activity and radiographic progression with RA patients. IGU is generally safe and tolerable and may have a good cost effectiveness. So iguratimod be a new useful option as small molecule DMARDs.

ACR Meeting Abstracts - https://acrabstracts.org/abstract/clinical-and-radiographic-outcome-of-iguratimod-for-rheumatoid-arthritis/