P06.14.a diagnosis and management of neuropathies related to immune checkpoint inhibitors: a case series

Abstract BACKGROUND Immune checkpoint inhibitors (ICIs) are associated with a wide range of neurotoxicities. Several types of neuropathies have been associated to immune checkpoint inhibitors (ICIs), from length-dependent sensory neuropathies to radiculoneuropathies similar to Guillain-Barré syndromes, with an overall incidence estimated to be between 0.1-1.2% of patients. Guidelines recommend prompt ICI discontinuation and the INTRODUCTION of steroids depending on the severity of the adverse event. However, the usage of IVIG or plasmapheresis (alternatively or in addition to steroids) has been reported in cases of Guillain-Barré-like syndromes. MATERIAL AND METHODS In this study, we report a retrospective consecutive series of patients with an ICI-related neuropathy referred to our department between 2016 and 2021, with the intent to describe their clinical and para-clinical features and the outcome after ICI discontinuation and steroids. RESULTS We identified 12 cases of acute peripheral nervous system involvement, with a predominant sensory pattern. The median onset of symptoms from ICI initiation was 18 weeks, and the median number of ICIs doses was 3. Electrophysiological studies, done in 11 patients, showed a radiculopathy in 9 cases, associated with an axonal neuropathy in 3, and a demyelinating neuropathy in 2 cases. Altogether, these findings are consistent with Guillain-Barré-like syndrome. ICIs were stopped in all patients and steroids started in 7 patients, leading to a favourable outcome (complete recovery =7, partial recovery =4, stability =1). CONCLUSION This consecutive retrospective series identifies Guillain-Barré-like syndrome as the main clinical pattern of immune related neuropathies. We did not observe any case of length-dependent axonal neuropathy without an associated root involvement. Our systematic management, consisting of ICI discontinuation in all patients and steroids in more severe cases, seems a valid strategy. On the other hand, our results do not support the use of IVIG or other treatments.