Tocilizumab and Rituximab in Systemic Sclerosis: A Real-Life Retrospective Observational Study Across Different Clinical Phenotypes

Objectives: To describe the efficacy and safety of tocilizumab (TCZ) and rituximab (RTX) in real-world patients with systemic sclerosis (SSc), across different clinical phenotypes and lines of therapy, evaluating both global clinical outcomes and lung function. Methods: SSc patients treated with TCZ (n = 27) or RTX (n = 23) were retrospectively followed for 12–24 months. Clinical measures, including modified Rodnan Skin Score (mRSS), C-reactive protein (CRP), and revised EUSTAR activity index 2017 (RAI), as well as spirometric parameters, were recorded at baseline and 6, 12, and 24 months. Statistical methods for repeated measures were applied to investigate outcome trends. Given the baseline differences, between-group comparisons were considered exploratory. Results: RTX was used earlier in disease course, while TCZ was mainly used as a rescue therapy. In both groups, mRSS, CRP levels and RAI significantly decreased over time. RTX-treated patients showed a greater absolute mRSS improvement, in line with higher baseline skin scores. No treatment discontinuations due to adverse events occurred in either group; one death and one discontinuation due to inefficacy were observed in the TCZ group. Among SSc-ILD patients, FVC% showed a modest decline in both groups, while DLCO% remained overall stable, and only a few patients met the OMERACT criteria for functional progression. Conclusions: In this real-world, single-center cohort of SSc patients, both agents were associated with a positive impact on disease activity, with a low rate of lung progression and with favorable safety profiles. Owing to substantial baseline imbalances and confounding by indication, between-group comparisons do not allow firm conclusions on comparative effectiveness. Overall, these data support the use of both agents in different clinical scenarios.