Ofatumumab for refractory opsoclonus-myoclonus syndrome following treatment of neuroblastoma.

Opsoclonus-myoclonus syndrome (OMS) may be associated with ANNA-1 (anti-Hu) autoantibodies. The standard treatment with IVIG, steroids, and anti-CD20 monoclonal antibody may fail, and optimal therapy is unknown. A patient developed OMS with high-titer ANNA-1 following recovery from neuroblastoma. She failed standard therapy and had only transient response to rituximab. Treatment with the humanized anti-CD20 monoclonal antibody ofatumumab combined with methotrexate resulted in transient neurologic improvement and decrease of ANNA-1. This suggests that ofatumumab combined with methotrexate should further be considered OMS patients, particularly in refractory disease.