We identified 7 patients who received cyclophosphamide in pulse doses of 1 g associated with methylprednisolone, 1 g every 2 months (500-700 mg/m2, according to each patient's body surface area) as a first-line treatment, within a mean of 17 months from the first demyelinating event (optic neuritis, myelitis, or both) (Table). During cyclophosphamide therapy, 5 patients continued relapsing and/or worsening, 1 patient died owing to a severe NMO relapse, and 1 abandoned follow-up at our center (Table); only 1 patient remained clinically stable. The remaining 5 patients on follow-up were switched to azathioprine associated with prednisone after clinical judgment of cyclophosphamide inefficiency. After treatment modification, there was a decrease in annualized relapse rate and/or progression index, with some patients showing improvement in their Expanded Disability Status Scale scores (Table). Patient 1 further showed an increase in annualized relapse rate and received rescue therapy with intravenous immunoglobulin every 2 months.