MOGAD is a potentially relapsing autoimmune demyelinating disease with less morbidity than aquaporin-4-IgG-positive neuromyelitis optica spectrum disorder. The optimal strategy for maintenance immunotherapy in MOGAD is uncertain.

A retrospective chart review of MOGAD patients at four tertiary-care centers in the US and Europe was performed. Patients included were: 1) diagnosed with MOGAD, 2) incident at the participating centers (seen initially with no more than 1 attack), and 3) observed for at least 3 years without any chronic immunotherapies other than steroids. Outcomes were collected at least 3 months after the last attack.

There were 55 incident cases observed for at least 3 years without chronic steroid-sparing immunotherapy. The median age of onset was 23.7 (IQR 8.9-47.0) years, 42% had a pediatric onset (<18 years), 66% were female, and 87% were White. During the median 75.8 (IQR 54.2-125.5) months of observation without chronic immunotherapy, 36.4% suffered a relapse with a median of 1 (IQR 1-2) attack. The median Expanded Disability Status Scale (EDSS) scores after recovery from the first attack and at the final follow-up was 0 (IQR 0-1.0) (p = 0.068). The median logMAR visual acuity of the worse eye was also unchanged with both being 0 (IQR 0-0, 0-0.1) (Snellen equivalent of 20/20) (p = 0.317). Seroreversion to MOG-IgG negative was seen in 11/41 (27%) patients with paired serum testing. Overall, three (6%) patients received >10 mg/day of oral prednisone for at least 6 months. Nine (16%) patients eventually received a steroid-sparing maintenance immunotherapy.

Without chronic immunotherapy, some MOGAD patients had relapses, but overall did not have a significant decline in either EDSS or visual acuity. Close observation with timely acute treatment for relapses may be justified in certain MOGAD patients.