Efficacy and safety of rituximab versus intravenous cyclophosphamide for systemic sclerosis-associated interstitial lung disease: a retrospective cohort study.

BACKGROUND

The efficacy of rituximab (RTX) for the treatment of systemic sclerosis-associated interstitial lung disease (SSc-ILD) has not been fully established. This study compared the efficacy and safety of RTX and intravenous cyclophosphamide (CY) for SSc-ILD.

METHODS

This retrospective study compared the efficacy and safety of RTX (20 patients) and CY (30 patients) after adjusting for the stabilised inverse probability of treatment weighting based on propensity scores. The efficacy endpoints were the absolute changes in forced vital capacity (FVC) and serum Krebs von den Lungen-6 (KL-6) levels from baseline to 6 and 12 months after treatment. The incidence of progression based on the definition of progressive pulmonary fibrosis was also recorded. The safety endpoint was the frequency of adverse events.

RESULTS

The clinical characteristics of the two groups were well-balanced after adjusting for confounders (i.e., FVC, nintedanib use, and newly diagnosed cases). From baseline to 6 and 12 months after the start of treatment, the median FVC increased by 50 and 60 ml in the RTX group and 40 and 15 ml in the CY group, respectively, with no difference after adjustment. The changes in serum KL-6 levels and the incidences of progression were identical in both groups after adjustment. The overall adverse events were similar in both groups after adjustment.

CONCLUSIONS

RTX demonstrated comparable safety and efficacy as CY in patients with SSc-ILD. Thus, RTX may be an alternative to CY for the treatment of SSc-ILD.