AB1231 EFFICACY AND SAFETY OF RITUXIMAB FOR SYSTEMIC SCLERODERMA -SINGLE CENTER ANALYSIS IN JAPAN-
Authors: H. Yamaguchi, Y. Ushio, T. Miyagi, H. Shimada, R. Wakiya, K. Sugihara, R. Kagawa, M. Mizusaki, S. Nakashima, H. Dobashi
Journal: Annals of the Rheumatic Diseases (2024)

<h3>Background:</h3> Rituximab (RTX), an anti-CD20 antibody, has recently become an effective treatment for systemic sclerosis, which causes progressive fibrotic lesions in multiple organs. The efficacy and safety of rituximab therapy must be investigated in real-world clinical use, as there is only evidence from a small number of clinical trials. <h3>Objectives:</h3> To evaluate the short-term efficacy and safety of RTX for cutaneous sclerosis and interstitial lung disease (ILD) in systemic sclerosis patients in at our institution. <h3>Methods:</h3> Systemic sclerosis patients diagnosed using ACR/EULAR Systemic Sclerosis Classification Criteria 2013 and treated with RTX from June 2021 to October 2023 and available for evaluation after six months of treatment were included. Efficacy after 6 months of RTX treatment was analyzed for changes in modified Rodnan's total skin thickness score (mRSS) for skin effect, %FVC, %DLCO, and serum KL-6 for ILD. The safety of rituximab therapy was examined by the occurrence of adverse events at 6 months. <h3>Results:</h3> Of the 29 patients treated with RTX for systemic sclerosis at our institution, 11 completed the 24-week evaluation; mean age at RTX induction was 59.5 ± 10.4 years and disease duration was 10.2 ± 9.8 years. Four patients received concomitant immunosuppressive drugs (azathioprine, mycophenolate mofetil, and tacrolimus), three of whom also received nintedanib. ILD complication was observed in 9 of 11 SSc patients. The mRSS, which was 14.8 ± 12.6 before RTX introduction, significantly decreased to 4.3 ± 6.2 after 24 weeks. The %FVC and %DLCO at the start of rituximab treatment were 76.6 ± 22.9% and 57.0 ± 19.4%, respectively, and were 78.1 ± 24.4% and 50.0 ± 15.3% at 24 weeks after, respectively. KL-6 was 720.7±434.1U/mL before induction and decreased by 48.6±183.1U/mL after induction. In the analysis of adverse events, two patients had complications of infection, bacterial pneumonia and COVID-19, respectively. Other serious adverse events included one patient treated with rituximab monotherapy who had grade 4 severe thrombocytopenia, which improved within a few days. <h3>Conclusion:</h3> In our clinical practice,RTX therapy showed to improve scleroderma and inhibit ILD progression in patients with systemic sclerosis. However, additional caution is needed because of adverse events, such as severe thrombocytopenia, that have not been observed in clinical trials. <h3>REFERENCES:</h3> [1] Satoshi Ebata, Ayumi Yoshizaki, Koji Oba, Kosuke Kashiwabara, Keiko Ueda, Yukari Uemura,et al. Safety and efficacy of rituximab in systemic sclerosis (DESIRES): a double-blind, investigator-initiated, randomised, placebo-controlled trial. The Lancet Rheumatology Vol 3, ISSUE 7, E489-E497, 2021. [2] Rubio-Rivas M, Royo C, Simeón CP, Corbella X, Fonollosa V. Mortality and survival in systemic sclerosis: systematic review and meta-analysis. Semin Arthritis Rheum, 44: 208-219, 2014. [3] Distler O Highland KB Gahlemann M et al. Nintedanib for systemic sclerosis-associated interstitial lung disease. N Engl J; 380: 2518-2528, Med. 2019. <h3>Acknowledgements:</h3> <b>NIL.</b> <h3>Disclosure of Interests:</h3> <b>None declared.</b>