Immune-related adverse events (irAEs) of immune check point inhibitors (ICIs); North- East of England experience

<h3>Background</h3> While ICIs have revolutionized cancer treatment, their use can trigger diverse immune- related adverse events(irAEs) that are potentially fatal. This case series from two tertiary centers in North East England explores the challenges posed by ICIs, and the importance of early identification and tailored therapeutic approach. <h3>Case Presentations</h3> <b>Case-1</b> A 41-year-old female received Nivolumab for recurrent thymic sarcoma. She developed myasthenia-myositis-myocarditis overlap syndrome presenting with oculobulbar and proximal muscles weakness, and respiratory failure requiring prolonged ITU admission. Prompt intervention with steroids, pyridostigmine and plasmapheresis resulted in a successful outcome. <b>Case-2</b> A 72-year-old male treated with Atezolizumab for metastatic bladder cancer presented acutely with Guillain-Barré-like syndrome. He required NIV for respiratory failure and was felt to be too frail for plasma exchange. He responded well to high dose steroids and intravenous immunoglobulin. <b>Case-3</b> A 70-year-old male with malignant melanoma developed IDDM, and myasthenia gravis acutely following Pembrolizumab treatment. Successful management with pyridostigmine and steroids obviated the need for further immunotherapy. <h3>Conclusion</h3> These cases underscore the importance of vigilance in identifying ICI-related complications, particularly neuromuscular ones, to optimize therapeutic interventions and enhance outcomes. Treatment needs to be balanced between frailty and cancer prognosis with aggressiveness of intervention. A multidisciplinary approach is crucial in navigating the complexities of ICI-associated irAEs.