Prospective Evaluation of Maintenance Plasma Exchange (mPLEX) for Attack Prevention in Neuromyelitis Optica Spectrum Disorder: Preliminary Feasibility, Safety, and Efficacy Data (P5.265)

OBJECTIVE: To report preliminary data from a prospective study of mPLEX for neuromyelitis optica spectrum disorder (NMOSD). BACKGROUND: Rescue PLEX is often used for acute corticosteroid-refractory NMOSD attacks. Anecdotal and retrospective studies suggest a potential role for mPLEX in attack prevention but feasibility, safety, and optimal treatment regimen are unclear. DESIGN/METHODS: Prospective observational study of NMOSD patients (target n=14) planning to initiate mPLEX. Clinical and laboratory data were collected at screening and quarterly for 12 months. Treatment plans, including PLEX frequency, were at the treating neurologist’s discretion. RESULTS: 9 subjects were consented. Of the 6 subjects who received mPLEX, 5 were female, all were aquaporin-4 antibody (AQP4-IgG) seropositive, median age was 62y, and median disease duration was 7.6y. Reasons for mPLEX included drug treatment failure (n=3), avoidance of immunosuppression (n=1 each with progressive multifocal leukoencephalopathy and hepatitis C), and subject preference (n=1). All subjects required central venous access. mPLEX was used as monotherapy (n=3) or with drug immunotherapy (n=3). mPLEX courses consisted of 1 exchange every 10-14 days (n=4) or 3 exchanges each month (n=2); >95[percnt] of planned exchanges were completed. mPLEX use ranged from 5-24 months with 4 subjects continuing after study completion. During mPLEX treatment, 4/6 subjects remained relapse-free; relapses occurred with mPLEX subjects using mPLEX as monotherapy (n=1) and in combination with rituximab (n=1). Median EDSS scores were 5.0 (range 3.5-8.0) and 5.25 (2.5-8.0) at screening and final visit, respectively. Major adverse effects included catheter-related infection (n=4), thrombus (n=1) and receipt of contaminated calcium solution (n=1). Two subjects continued post-study mPLEX using AV fistulas. CONCLUSIONS: mPLEX is feasible and may contribute to relapse prevention in selected NMOSD patients. Catheter-related complications are common when central access is required. We plan continued recruitment and analysis of AQP4-IgG kinetics to further evaluate mPLEX regimens. Study Supported by TerumoBCT. Disclosure: Dr. Wingerchuk has received personal compensation for activities with Medimmune, Alexion, and Chugai. Dr. Wingerchuk has received research support from Alexion and TerumoBCT. Dr. Weinshenker has received personal compensation for activities with Novartis, Biogen Idec, and Mitsubishi Pharmaceuticals, MedImmune Pharmaceuticals, Alexion Pharmaceuticals, Chugai Pharmaceutical, and Novartis. Dr. Weinshenker has received royalty pay Dr. Carter has received personal compensation for activities with EMD Serono as a data and safety monitoring committee member. Dr. Carter9s institution has received research support from Actelion Pharmaceuticals, Genzyme, and Roche. Dr. Pittock9s institution has received compensation for activities with Alexion Pharmaceuticals, Medimmune, and Chugai Pharma. Dr. Pittock and his institution stand to receive royalty payments in the technology entitled "Neuromyelitis Optica Autoantibodie Dr. Lennon stands to receive royalty payments for commercial assays to detect of Aquaporin 4-specific Autoantibody. Research support from MedImmune for a laboratory diagnostics study. Dr. Lucchinetti stands to receive royalty payments for commercial assays to detect aquaporin 4-specific autoantibody. Caridian BCT