Real-World Study of the Use of Iguratimod to Treat Chronic/Refractory ITP

Introduction: Immune thrombocytopenia (ITP) is an acquired, organ-specific, autoimmune disease and one of the most common bleeding disorders that seriously endangers human health. Iguratimod is a small molecule compound that is widely used as a novel antirheumatic drug in the treatment of rheumatoid arthritis in China and Japan. Iguratimod inhibits the production of several inflammatory cytokines, including IL-1, IL-6, IL-8, and tumor necrosis factor (TNF), and reduces the production of immunoglobulins. Th1 and Th17 cell counts were significantly reduced in patients with rheumatoid arthritis after treatment with iguratimod. The low long-term remission rate of ITP makes the investigation of its pathogenesis and the search for new treatments important clinical problems to be solved. Abnormal T-cell function and anti-platelet antibody production play important roles in the pathogenesis of ITP, and iguratimod is a therapeutic agent that could potentially be used to treat ITP. Previous clinical studies have shown that iguratimod can increase platelet levels in patients with dry syndrome. The potential of iguratimod for treating anti-platelet antibody-mediated thrombocytopenia in mice with ITP by modulating T-cell differentiation suggests that iguratimod may be a new approach for the prevention and treatment of ITP. Recent retrospective clinical studies and case reports have also shown that the use of iguratimod in autoimmune diseases is associated with good safety and efficacy. In conclusion, the aim of this study was to investigate the effect of iguratimod on the treatment of ITP.

Methods: The study began in December 2020 and is ongoing. A total of 76 patients who were treated with iguratimod for at least 3 months were selected. Of these, 51 patients were treated for more than 6 months, and 30 patients were treated for at least 12 months. Five patients withdrew from observation after 3 months: two patients due to NR, three patients due to epidemic and financial reasons, and no patients due to AE. Key secondary endpoints included initial response by Day 14 (OR, platelet count ≥30×10⁹/L, at least a 2-fold increase in baseline platelet count, and absence of bleeding; and CR, platelet count ≥ 100×10⁹/L), duration of response, bleeding scores, and adverse events (AEs). This study was registered with ClinicalTrials.gov ().

Results: At baseline, 73.5% of the patients reported symptoms of grade 1 to 4 bleeding. After 3 months of treatment, the proportion of patients with any bleeding symptoms decreased to 61.8% and remained below baseline throughout the study period. At baseline, 63 patients reported the use of concomitant medications, which decreased by 36.5% between 3 and 6 months. The most frequently discontinued or reduced medications were glucocorticoids and rituximab. All the patients took the medication in strict accordance with the instructions and medical advice. The patients were monitored monthly to assess blood, liver, kidney function, and no abnormalities in laboratory tests, such as elevated transaminases or lymphocytopenia, were observed.

Conclusions: Iguratimod has good efficacy and safety in the treatment of ITP and has the potential to become a new treatment for ITP.

No relevant conflicts of interest to declare.