Efficacy of the anti–IL-6 receptor antibody tocilizumab in neuromyelitis optica: A pilot study

OBJECTIVE:To evaluate the safety and efficacy of a humanized anti–interleukin-6 receptor antibody, tocilizumab (TCZ), in patients with neuromyelitis optica (NMO). METHODS:Seven patients with anti–aquaporin-4 antibody (AQP4-Ab)-positive NMO or NMO spectrum disorders were recruited on the basis of their limited responsiveness to their current treatment. They were given a monthly injection of TCZ (8 mg/kg) with their current therapy for a year. We evaluated the annualized relapse rate, the Expanded Disability Status Scale score, and numerical rating scales for neurogenic pain and fatigue. Serum levels of anti-AQP4-Ab were measured with AQP4-transfected cells. RESULTS:Six females and one male with NMO were enrolled. After a year of TCZ treatment, the annualized relapse rate decreased from 2.9 ± 1.1 to 0.4 ± 0.8 (p < 0.005). The Expanded Disability Status Scale score, neuropathic pain, and general fatigue also declined significantly. The ameliorating effects on intractable pain exceeded expectations. CONCLUSION:Interleukin-6 receptor blockade is a promising therapeutic option for NMO. CLASSIFICATION OF EVIDENCE:This study provides Class IV evidence that in patients with NMO, TCZ reduces relapse rate, neuropathic pain, and fatigue.