The value of rituximab treatment in primary Sjögren's syndrome

The rationale for B cell depletion therapy with rituximab in primary Sjögren's syndrome relies upon the well-established role of B cell hyperactivity in immunopathogenesis. In line with this notion, several biomarkers of B cell activity are significantly affected by treatment, both in the target organs and periphery. In contrast to most biological outcomes, clinical outcomes are not consistent between studies. Although two large RCTs did not meet their primary endpoint, several beneficial clinical effects of treatment have been shown. As discussed in this review, differences in study design and patient characteristics could explain the variation in results. Interestingly, a newly developed composite endpoint of subjective and objective outcomes did show a significant effect of rituximab in one of the large RCTs. Response predictors need to be identified to define more targeted inclusion criteria and achieve precision medicine. The positive effects seen on biological and clinical parameters warrant future studies to investigate this promising treatment modality.