Rituximab treatment in lupus nephritis--where do we stand?

Renal involvement in systemic lupus erythematosus (SLE) is a severe disease manifestation in which novel therapeutic strategies are needed, especially in non-responding patients or patients who relapse after conventional treatment. Rituximab has been used as off-label treatment for lupus nephritis (LN) during the last decade, and to date reports on the clinical effects on more than 400 patients, including the randomized controlled LUNAR study population, have been published. Despite promising results obtained from observational studies and registries, with complete or partial renal response after 6-12 months in 67-77% of patients, the LUNAR trial failed to attain the primary endpoint and rituximab is today unlikely to be approved as treatment for LN. Rituximab has mainly been used as induction therapy in combination with standard of care but the optimal treatment protocol is still to be determined. From observational studies, rituximab has been shown to be efficient in both proliferative and membranous LN, and histopathological studies have demonstrated improvement in renal activity. Adverse events mainly include infusion reactions and infections. Although not approved for the treatment of LN, the currently available data support that rituximab may be used in severe, refractory cases of LN.