AB0693 EFFECTIVENESS OF RITUXIMAB IN PATIENTS WITH SYSTEMIC SCLEROSIS – EXPERIENCE IN A TERTIARY MEDICAL CENTER

Abstract

BackgroundThere is ample evidence of B cell involvement in the pathogenesis of fibrosis in systemic sclerosis (SSc), making it a promising target for the treatment of skin and lung fibrosis in SSc. However, data regarding the long-term use of B cell depletion in the treatment of this life-threatening connective tissue disease is scarce.ObjectivesThe primary aim of this study was to evaluate the safety and efficacy of long-term B cell depletion and to define the changes on both cutaneous and visceral organ involvement after rituximab (RTX) therapy in SSc patients over time, in a tertiary hospital.MethodsA prospective observational case-control study, conducted between 2016 and 2021, enrolled 10 SSc patients, who fulfilled the ACR/EULAR 2013 classification criteria for scleroderma and who had received RTX infusions at least once. All patients had been taking immunosuppressive therapy previously.The following clinical data were included into the analysis: disease activity by the EUSTAR activity index, skin fibrosis by the modified Rodnan Skin Score (mRSS), interstitial lung disease by lung function tests including forced vital capacity (FVC), diffusing capacity of the lung for carbon monoxide (DLCO) and high-resolution CT (HRCT). For the comparison of non-parametric data at two time points, Wilcoxon matched paired Student’s t-test was used.ResultsThe study included 10 patients (all female), with a mean age of 52.9 years, most of them with diffuse subset (9/10), treated with RTX between 2016 and 2021. Average duration of disease before the RTX therapy was 27.6 months. Mean baseline mRSS was 19.3 and mean EUSTAR activity index was 4.48. Seven patients received 2 courses of RTX for at least 6 months, four of which were evaluated 1 year after the beginning of RTX therapy. We found a statistically significant improvement in mRSS (p=0.02) and EUSTAR activity index values (p=0.02), when comparing baseline levels with those found at each follow-up visit. Furthermore, all the patients who were treated with RTX early in the disease course achieved better results at 6 months follow-up. There was no significant change in PFT’s, DLCO and chest HRCT lesions in all patients, neither in the subgroup with early disease, nor in the subgroup with worsening, progressing pulmonary function, during the follow up period.ConclusionOur results suggest that B cell depletion, in patients with SSc, leads mainly to a clinically relevant decrease in skin involvement and to a stabilization of disease activity after 6 and 12 months of use. The study did not find a clear beneficial effect on pulmonary function during short-term follow-up. Despite these considerations, our results indicate that the course of lung disease did not worsen in our patients. At 6-year follow-up the safety of single and repeated courses of the drug was confirmed. While the study provides important insights into the use of RTX in SSc, it is limited by the low number of patients, the lack of a sufficient control arm and the single center design.