DGN Kongress 403 Interleukin-6-receptor blocade in neuromyelitis optica spectrum and MOG associated disorders Gero Lindenblatt1, Ilya Ayzenberg2, Ingo Kleiter2,3, Anna Gahlen2, Giovanni Novi4, Helen Hayward-Könnecke5, Sven Schippling5, Paulus Rommer6, Barbara Kornek6, Tobias Zrzavy6, Jonathan Ciron7, Bertrand Audoin8, Achim Berthele9, Katrin Giglhuber9, Hélène Zéphir10, Tania Kümpfel11, Robert Berger12, Joachim Röther12, Vivien Häußler13, Jan-Patrick Stellmann14,15, Daniel Whittam16, Anu Jacob16, Markus Krämer17, Antoine Gueguen18, Romain Deschamps18, Antonios Bayas19, Martin Hümmert20, Corinna Trebst20, Axel Haarmann21, Sven Jarius22, Brigitte Wildemann22, Matthias Grothe23, Nadja Siebert24, Friedemann Paul24, Nicolas Collongues25, Romain Marignier26, Michael Levy27, Michael Karenfort28, Michael Deppe29, Ralf Gold2, Philipp Albrecht30, Hans-Peter Hartung30, Orhan Aktas30, Marius Ringelstein30,31 1Johanna Etienne Hospital, Department of Neurology, Neuss, Deutschland; 2St. Josef Hospital, Ruhr University Bochum, Department of Neurology, Bochum, Deutschland; 3Marianne-Strauß-Klinik, Behandlungszentrum Kempfenhausen für Multiple Sklerose Kranke, Berg, Deutschland; 4San Martino Hospital, Department of Neurology, Genova, Italy; 5University Hospital Zurich, Department of Neurology, Zürich, Switzerland; 6Medical University of Vienna, Department of Neurology, Vienna, Austria; 7Université de Toulouse, Department of Neurology, Toulouse, France; 8APHM Hôpital de la Timone, Department of Neurology, Marseille, France; 9Klinikum rechts der Isar, Technical University Munich, Department of Neurology, München, Deutschland; 10University of Lille, U995, LIRIC, CHU of Lille, Department of Neurology, Lille, France; 11Ludwig Maximilian University, Faculty of Medicine, Institute of Clinical Neuroimmunology, München, Deutschland; 12Asklepios Klinik Altona, Department of Neurology, Hamburg, Deutschland; 13University Medical Center Hamburg-Eppendorf, Department of Neurology and Institute of Neuroimmunology and MS (INIMS), Hamburg, Deutschland; 14APHM Hôpital de la Timone, CEMEREM, Department of Neurology, Marseille, France; 15Aix Marseille Univ, CNRS, CRMBM, UMR 7339, Department of Neurology, Marseille, France; 16The Walton Centre, Department of Neurology, Liverpool, United Kingdom; 17Alfried Krupp Hospital, Department of Neurology, Essen, Deutschland; 18Fondation Ophtalmologique Adolphe de Rothschild, Department of Neurology, Paris, France; 19University Hospital Augsburg, Department of Neurology, Augsburg, Deutschland; 20Hannover Medical School, Department of Neurology, Hannover, Deutschland; 21University of Würzburg, Department of Neurology, Würzburg, Deutschland; 22University of Heidelberg, Department of Neurology, Molecular Neuroimmunology Group, Heidelberg, Deutschland; 23University Hospital Greifswald, Department of Neurology, Greifswald, Deutschland; 24Charité Universitätsmedizin Berlin, NeuroCure Clinical Research Center and Experimental and Clinical Research Center, Berlin, Deutschland; 25University Hospital Strasbourg, Department of Neurology, Straßburg, France; 26Hospices Civils des Lyon, Department of Neurology, Lyon, France; 27Massachusetts General Hospital and Harvard Medical School, Department of Neurology, Boston, United States; 28Heinrich-Heine-University Düsseldorf, Medical Faculty, University Children‘s Hospital, Neonatology and Pediatric Cardiology, Department of General Pediatrics, Düsseldorf, Deutschland; 29University Hospital Münster, Department of Neurology, Münster, Deutschland; 30Heinrich-Heine-University Düsseldorf, Medical Faculty, Department of Neurology, Düsseldorf, Deutschland; 31Heinrich-Heine-University Düsseldorf, LVR-Klinikum, Center for Neurology and Neuropsychiatry, Department of Neurology, Düsseldorf, Deutschland Importance: Neuromyelitis optica spectrum disorders (NMOSD) with aquaporin-4 serum antibodies (AQP4-ab) as well as relapsing myelin oligodendrocyte glycoprotein antibody associated disorders (MOGAD) are characterized by disabling attacks to the optic nerve and spinal cord. Interleukin-6 (IL-6) receptor blockade proved to be safe and effective in attack prevention in shorter follow-up NMOSD cohorts and was barely investigated in MOGAD. Objective: To evaluate long-term safety and efficacy of tocilizumab (TCZ), a humanized antibody targeting the IL-6 re- ceptor, in a large cohort of AQP4-ab seropositive and –negative NMOSD patients, as well as in patients with MOGAD. Design: Retrospective observation between December 2010 and November 2019. Setting: Neurology departments at 23 tertiary referral centers in Germany (13), France (5), Austria (1), Italy, (1), Switzerland (1), United Kingdom (1) and United States of America (1). Participants: Fifty-seven predominantly female (n=44; 77%) patients with AQP4-ab seropositive (AQP4+; n=36; 63%) and AQP4-ab seronegative NMOSD (AQP4-; n=7; 12%) as well as MOGAD (n=14; 25%) mainly of Caucasian descent (n=50; 88%), were switched to TCZ mono- or add-on therapy intravenously (n=56) or subcutaneously (n=1), following immuno- therapies including B-cell depleting agents. 48 93. Kongress der Deutschen Gesellschaft für Neurologie • 4. – 7. November 2020