2 grams versus 1 gram rituximab as maintenance schedule in multiple sclerosis, neuromyelitis optica spectrum disorders and related diseases: What B-cell repopulation data tell us.

Abstract

Rituximab (RTX) is largely used as a long-term maintenance therapy in various inflammatory neurological diseases. Reducing the dose of maintenance therapy of RTX from 2 grams every 6 months (traditional regimen) to 1gram every 6 months (reduced regimen) is a widely applied practice, with the assumption that it decreases the risk of side effects while maintaining efficacy. In order to better describe the biological consequences of this strategy, we retrospectively compared, in a single center, the B-cell count after the traditional regimen and after the reduced regimen in patients who underwent both (n=161). The rate of patients with B-cell repopulation was not significantly different between traditional and reduced regimens (9.9% vs 15.6%, p=0.18). Among the 145 patients who did not have B-cell repopulation following the traditional regimen, B-cell repopulation following the reduced regimen occurred in only 16 cases (11.0%) and was usually slight: 11/16 patients had only 1% of CD19+ cells. These data emphasize the relevance of 1g of RTX as maintenance therapy and the fact that 2g of RTX is generally an overtreatment in inflammatory neurological diseases.