Indications and Safety of Rituximab in Pediatric Neurology: A 10-Year Retrospective Study

Safety of Obinutuzumab in Children With Autoimmune Encephalitis and Early B-Cell Repopulation on Rituximab

BACKGROUND

Rituximab (RTX) resistance or early B-cells repopulation were observed in children but only few publications reported the use of Obinutuzumab and no recommendations were made concerning the dosage for children.

METHODS

This study was a single-center retrospective cohort study of all the children followed-up in the Pediatric Neurology Department of Necker-Enfants malades Hospital in Paris, France, and treated with obinutuzumab, between November 1, 2019, and November 1, 2021.

RESULTS

A total of eight children (three females, median age 4.5 years) were treated. Seven patients presented with autoimmune encephalitis and one with myeloradiculitis. The median delay of B-cell repopulation after a course of RTX was 87 days (range 41 to 160). A switch to obinutuzumab (anti-CD20) was performed for eight children. The median duration between the first RTX infusion and obinutuzumab administration was 6.6 months. The dosage regimen for obinutuzumab was one infusion of 1000 mg/1.73 m2, that is to say 580 mg/m2 (maximum 1000 mg/infusion), by extrapolation from the adult dosage. The median delay of B-cell repopulation after one course of obinutuzumab was 230 days (range 66 to 303 days) vs 87 days after one course of RTX (P < 0.01). None of the patients presented side effects with obinutuzumab treatment. All patients had a favorable evolution at the last-follow up. Median follow-up was 1.6 years.

CONCLUSIONS

This study reports the use of obinutuzumab in neurological inflammatory diseases in a pediatric population. Obinutuzumab seems to have a better biological efficacy than RTX with a longer time of B-cell repopulation.

Successful use of tacrolimus for treatment-refractory neuroblastoma-associated opsoclonus-myoclonus-ataxia syndrome: A case series

Opsoclonus-myoclonus-ataxia syndrome (OMAS) is an autoimmune central nervous system disorder, primarily manifesting as a paraneoplastic sequalae to neuroblastoma, and characterized by motor disorders and behavioral disturbances. OMAS is typified by aberrant B-cell and T-cell activation. Current treatment involves immunosuppression using corticosteroids, intravenous immunoglobulin, and rituximab. However, these approaches often lead to treatment-related toxicities and symptomatic recurrences with chronic neurocognitive impairment. We treated three children with refractory neuroblastoma-associated OMAS with tacrolimus, a T-cell-targeting calcineurin inhibitor, effectively controlling symptoms within a month and enabling the discontinuation of immunosuppression with minimal side effects. Tacrolimus shows promise as a therapeutic option for refractory OMAS.