Efficacy of glatiramer acetate in neuromyelitis optica spectrum disorder: a multicenter retrospective study

Glatiramer acetate (GA) is an approved therapy for relapsing–remitting multiple sclerosis, but its efficacy for the prevention of attacks in neuromyelitis optica spectrum disorder (NMOSD) remains unknown. We did a multicenter retrospective analysis of GA-treated patients with NMOSD, identified through a national registry. Annualized relapse rate and expanded disability status scale (EDSS) were the main outcome measures. We identified 23 GA-treated patients (21 female, 16 aquaporin-4 antibody-positive). GA was given for <6 months in seven patients; reasons for stopping were relapses (n = 3), confirmation of NMOSD (n = 2) and side effects (n = 2). Of 16 patients treated ≥6 months with GA (15 female, 11 aquaporin-4 antibody-positive), 14 experienced at least one relapse. There was no reduction in the mean annualized relapse rate in the total group (1.9 ± 1.1 before vs. 1.8 ± 1.4 during GA therapy), as well as in those patients who were aquaporin-4 antibody-positive, or had a history of prior immunotherapy or not. The median EDSS increased (2.5 start vs. 3.5 finish of GA, P < 0.05). GA therapy was discontinued in 15/16 patients; reasons were therapeutic inefficacy in 13 and post-injection skin reactions in two patients. We conclude that GA is not beneficial for preventing attacks in most patients with NMOSD, particularly in aquaporin-4 antibody-positive cases.