Safety and Efficacy of Iguratimod in the Treatment of Chronic GVHD

This is a randomized, single-center phase 3 clinical trial without blinding. Iguratimod, as a rheumatoid arthritis medication, is used to treat autoimmune diseases such as Sjögren's syndrome. It has acceptable side effects, good clinical availability, and is cost-effective. The investigators plan to recruit participants for a clinical trial to evaluate the efficacy and safety of Iguratimod in the treatment of chronic GVHD.

The investigators plan to recruit participants for a clinical trial to evaluate the efficacy and safety of Iguratimod in the treatment of chronic GVHD. Iguratimod possesses anti-inflammatory, anti-bone resorption, immune modulation, and anti-fibrotic effects. Considering that the pathogenesis of chronic GVHD involves inflammation, immune dysregulation, and fibrosis, Iguratimod is theoretically a potential treatment for cGVHD. In animal experiments, Iguratimod has demonstrated the ability to alleviate glandular inflammation, inhibit BAFF activity, reduce antibody production, and mitigate lung fibrosis. These findings provide a basis for Iguratimod's potential use in the treatment of cGVHD based on animal experimentation. In clinical practice, Iguratimod has been shown to alleviate dry mouth and dry eye symptoms in patients with Sjögren's syndrome. Since cGVHD shares similar symptoms of dry mouth and dry eye, with mechanisms resembling those in Sjögren's syndrome, it is reasonable to infer that Iguratimod used in the treatment of cGVHD patients could alleviate these symptoms and improve their quality of life. Similarly, organ damage in the lungs of cGVHD patients is mainly manifested as TGF-β activation-induced interstitial changes and pulmonary fibrosis. Studies suggest that adding Iguratimod to the treatment of patients with Sjögren's syndrome-induced lung interstitial changes and pulmonary fibrosis can inhibit TGF-β expression, thereby improving lung function and reducing the progression of pulmonary fibrosis. Therefore, the investigators hypothesize that Iguratimod is also effective against cGVHD-induced pulmonary fibrosis.