A pilot study of rituximab in immune-mediated inner ear disease

Immune-mediated inner ear disease (IMED) is a cause of rapidly progressive auditory dysfunction. Patients are often responsive to high-dose corticosteroids and the disease is believed to be mediated by an antibody to inner ear proteins. To date, no therapies have proven effective as corticosteroid-sparing agents. Rituximab is a monoclonal antibody that depletes B cells, resulting in a reduction in autoantibody production. For that reason, rituximab was evaluated in a small pilot study in patients with IMED to see if there was a signal suggesting benefit. In all, 5/7 patients met the primary endpoint of an improvement in pure tone average (500-3000 Hz) by 10 dB in at least one ear, or an improvement in word identification score by at least 12% at 24 weeks, both relative to screening precorticosteroid values after 1 course of treatment. No significant adverse events were reported. The results of this study suggest further evaluation of rituximab as a treatment for IMED is indicated.