Ab1171 Rituximab for Treatment of Systemic Sclerosis Associated Interstitial Lung Disease at Mount Sinai Medical Center

Background: Systemic Sclerosis is a complex, multisystem, fibrotic disease with interstitial lung disease (ILD) being a major cause of mortality. Studies have shown prevalence of ILD of up to 84 percent in Systemic Sclerosis. The treatment of Systemic Sclerosis associated ILD includes agents like mycophenolate, tocilizumab, and cyclophosphamide. Rituximab is an anti CD-20 monoclonal antibody drug which has been shown to have benefit in Systemic Sclerosis associated ILD, although its use in this condition is considered second line. Objectives: In this retrospective study, we compare the respiratory outcomes including pulmonary function tests (PFTs), CT chest findings, need for respiratory related hospitalization and survival of patients with Systemic Sclerosis related ILD who received Rituximab with control patients who did not receive Rituximab. Methods: The patients of this study were identified from the Mount Sinai/National Jewish Respiratory Institute Patient Registry and Biorepository. Patients were diagnosed with ILD based on either the findings of high resolution CT chest or a lung biopsy. Patients were included if they met the 2013 ACR/EULAR criteria for Systemic Sclerosis. Clinical improvement was defined as improvement in four domains after the use of Rituximab including pulmonary function tests (PFTs), CT chest findings, need for respiratory related hospitalization and survival. Results: Of the 791 patients in the registry, 85 patients received at least one dose of Rituximab, out of which 10 patients met the criteria for Systemic Sclerosis. A control group of 27 patients with Systemic Sclerosis who did not receive Rituximab was added. Both the control group and the Rituximab group were found to have similar demographics. More patients in the Rituximab group were treated with mycophenolate and steroids. In Rituximab group, 9 patients had a set of PFTs 12 months before and after the Rituximab and 6 patients had a CT chest 12 months before and after the Rituximab. Percent predicted FVC improved in one patient, was stable in 6 patients, and worsened in 2 patients. Percent predicted DLCO was stable in 7 patients and worsened in one patient. Out of the 6 patients with serial CT chests, 4 had stable CT chest findings, one had CT chest findings improve, and one worsened. 4 patients experienced an infection. 4 patients were admitted to the hospital for a noninfectious respiratory related reason. One out of the 10 patients expired. These outcomes were similar in the control group. Conclusion: In patients with Systemic Sclerosis associated ILD treated with Rituximab, the majority had stable or improved PFTs. Both the Rituximab and control group had similar respiratory outcomes. Although the outcomes were similar in both the groups, more patients in the Rituximab group were treated with mycophenolate and steroids suggesting refractory ILD. Further prospective studies are needed to assess the benefit of Rituximab in this subset of patients with ILD. REFERENCES: NIL. Acknowledgements: NIL. Disclosure of Interests: None declared.