Review of neurological complications following treatment with immune check- point inhibitors

Objective Immunotherapy with cytotoxic T lymphocyte-associated protein-4 (CTLA-4), programmed cell death protein-1 and ligand-1 (PD-1 and PD-L1) inhibitors are the most promising development in oncology. Neurological complications are reportedly seen in 2–4 % of patients treated with immune checkpoint inhibitors (CPI). Method This was an observational study which included all oncology and haematology patients who received the most common CPI (Ipilimumab, Nivolumab, and Pembrolizumab), either as monotherapy, in combination or sequentially between the periods of January 2017 to April 2019. Results Total of 375 patients received CPI during this period. The most common cancer was malignant melanoma, lung, head and neck and renal cancers. 199 patients had neurological complications, the vast majority due to metastasis or vascular complications related to the cancer. One hundred patients were identified as having neurological symptoms related to Immune therapy. 67 of these patients who were symptomatic received some sort of intervention for the neurological IRAE, which included change in immunotherapy, temporary or permanent suspension of treatment or steroids. Conclusion This is one of the largest series of cancer patients studied so far for neurological IRAEs following CPI therapy. Early diagnosis of these events is highly vital for effective treatment and cure of symptoms. Steroids hold the mainstay of treatment followed by IVIG/PLEX, possibly in a graded fashion based on severity. Long term studies are needed to establish a clear pathway and identify prognostic indicators. saiju.jacob@uhb.nhs.uk