Critically ill patients with severe immune checkpoint inhibitor related neurotoxicity: A multi-center case series

Purpose: Serious immune checkpoint inhibitor (ICI)-related neurotoxicity is rare. There is limited data on the specifics of care and outcomes of patients with severe neurological immune related adverse events (NirAEs) admitted to the Intensive Care Unit (ICU). Materials and methods: Retrospective study of patients with severe NirAEs admitted to the ICU at 3 academic centers between January 2016 and December 2018. Clinical data collected included ICI exposure, type of NirAE (central [CNS] or peripheral nervous system [PNS) disorders), and patient outcomes including neurological recovery and mortality. Results: Seventeen patients developed severe NirAEs. Eight patients presented with PNS disorders; 6 with myasthenia gravis (MG), 1 had a combination of MG and polyneuropathy and 1 had Guillain-Barre syndrome. Nine patients had CNS disorders (6 seizures and 5 had concomitant encephalopathy. During ICU admission, 65% of patients required mechanical ventilation, 35% vasopressors, and 18% renal replacement therapy. The median ICU and hospital length of stay were 7 (2–36) and 18 (4–80) days, respectively. Hospital mortality was 29%. At hospital discharge, 18% of patients made a full neurologic recovery, 41% partial recovery, and 12% did not recover. Conclusion: Severe NirAEs while uncommon, can be serious or even life-threatening if not diagnosed and treated early.