Intrathecal treatment trial of rituximab in progressive MS An open-label phase 1b study

Objectives To perform a phase 1b assessment of the safety and feasibility of intrathecally delivered rituximab as a treatment for progressive multiple sclerosis (PMS) and to evaluate the effect of treatment on disability and CSF biomarkers during a1-year follow-up period. Methods Three doses of rituximab (25 mg with a 1-week interval) were administered in 23 patients with PMS via a ventricular catheter inserted into the right frontal horn and connected to a subcutaneous Ommaya reservoir. Follow-ups were performed at 1, 3, 6, 9, and 12 months. Results Mild to moderate vertigo and nausea were common but temporary adverse events associated with intrathecal rituximab infusion, which was otherwise well tolerated. The only severe adverse event was a case of low-virulent bacterial meningitis that was treated effectively. Of 7 clinical assessments, only 1 showed statistically significant improvement 1 year after treatment. No treatment effect was observed during the follow-up period among 6 CSF biomarkers. Conclusions Intrathecal administration of rituximab was well tolerated. However, it may involve a risk for injection-related infections. The lack of a control group precludes conclusions being drawn regarding treatment efficacy. ClinicalTrials.gov identifier NCT01719159. Classification of evidence This study provides Class IV evidence that intrathecal rituximab treatment is well tolerated and feasible in PMS but involves a risk of severe infections.