TY - JOUR T1 - 11.30 Comparison of fixed high dose with variable low dose rituximab in neuromyelitis optica spectrum disorders JF - Journal of Neurology, Neurosurgery & Psychiatry JO - J Neurol Neurosurg Psychiatry SP - e9 LP - e9 DO - 10.1136/jnnp-2019-ABN-2.27 VL - 90 IS - 12 AU - Patricia Kelly AU - Daniel Whittam AU - Samantha Linaker AU - Kerry Mutch AU - Venkatraman Karthikeayan AU - Saif Huda AU - Anu Jacob Y1 - 2019/12/01 UR - http://jnnp.bmj.com/content/90/12/e9.2.abstract N2 - Introduction Rituximab is an effective treatment for neuromyelitis optica spectrum disorders (NMOSD) but the ideal dosing regimen is unknown. This study compares a standard fixed dosing regimen (2 g 6-monthly) with a lower variable dosing regimen (2 g induction, then 1–2 g on repopulation of CD19+ B-cells to ≥1% of circulating lymphocytes, tested monthly).Method Retrospective review of all rituximab-treated adult NMOSD patients who had at least 6months relapse-free follow-up from treatment initiation (n=52). Rituximab dosing fell into four groups: Purely fixed dosing (n=13), purely variable dosing (n=18), fixed then variable dosing (n=18), other (n=3).Results Median annualized relapse rate (ARR) was not significantly different between these groups. Pooled analysis of all fixed dosing (n=31, median duration 25 months) versus all variable dosing (n=36, median duration 38 months) showed median and mean ARRs of 0.00 and 0.10 in both groups. Patients on fixed dosing received a median 3.9 infusions/year; those on variable doing received only 1.5 infusions/year.Conclusion Variable dosing of rituximab with B-cell monitoring appears as effective as fixed dosing with lower cumulative drug doses. This approach led to reduced costs, increased patient convenience and has the potential for reducing side effects. ER -