Multicenter Study of Treatment Efficacy
Maureen A. Mealy, RN; Dean M. Wingerchuk, MD; Jacqueline Palace, FRCP, DM; et al
Abstract
Importance Neuromyelitis optica (NMO) is an inflammatory disease of the optic nerves and spinal cord that leads to blindness and paralysis. Effective immunosuppression is the standard of care for relapse prevention.
Objective To compare the relapse and treatment failure rates among patients receiving the 3 most common forms of immunosuppression for NMO: azathioprine, mycophenolate mofetil, and rituximab.
Design, Setting, and Participants We performed a retrospective, multicenter analysis of relapses in 90 patients with NMO and NMO spectrum disorder treated with azathioprine, mycophenolate, and/or rituximab at the Mayo Clinic and the Johns Hopkins Hospital during the past 10 years.
Main Outcome and Measure Annualized relapse rates.
Results Rituximab reduced the relapse rate up to 88.2%, with 2 in 3 patients achieving complete remission. Mycophenolate reduced the relapse rate by up to 87.4%, with a 36% failure rate. Azathioprine reduced the relapse rate by 72.1% but had a 53% failure rate despite concurrent use of prednisone.
Conclusions and Relevance Initial treatment with rituximab, mycophenolate, and, to a lesser degree, azathioprine significantly reduces relapse rates in NMO and NMO spectrum disorder patients. Patients for whom initial treatment fails often achieve remission when treatment is switched from one to another of these drugs.
Neuromyelitis optica (NMO) is an inflammatory demyelinating disease of the central nervous system (CNS) distinct from multiple sclerosis (MS). It is characterized by optic neuritis (ON), longitudinally extensive transverse myelitis (TM), and, in approximately 70% of cases, the presence in serum of IgG antibodies that target aquaporin 4 (AQP4-IgG; also known as NMO-IgG). Patients with neuromyelitis optica spectrum disorder (NMOSD) are seropositive for AQP4-IgG and have evidence of an inflammatory event consistent with NMO, including TM, ON, or brainstem inflammation. Disease-modifying treatment for relapse prevention in patients with NMO and NMOSD requires immunosuppression because some immunomodulatory therapies used for MS appear to aggravate NMO.1– 3 Although no placebo-controlled or comparative randomized controlled trials of immunosuppressive therapies have been conducted for NMO and there is no consensus on how to select initial therapy, there is evidence that azathioprine, mycophenolate mofetil, and rituximab are effective in reducing relapse rates.4– 10We conducted this retrospective study to compare relapse and treatment failure rates among NMO and NMOSD patients who received azathioprine, mycophenolate, or rituximab as their initial long-term immunosuppressive therapy at the Johns Hopkins Hospital and Mayo Clinic.