Exploring rare and severe toxicities in immunotherapy treatments

At the 2025 ASCO Annual Meeting, a session on severe immune-related toxicities was moderated by prof Sandrine Aspeslagh, reflecting the collaborative approach seen in BITOX, Belgium’s national multidisciplinary immunotoxicity board. The session brought together oncologists and organ specialists to discuss complex and life-threatening immune-related adverse events (irAEs) linked to immune checkpoint inhibitors. Presentations were given by Dr Evan Johnson, Dr John Probasco, and Dr Joëlle Salem, with a neurologist and cardiologist contributing to the multidisciplinary perspective.

Dr Joe-Elie Salem, a cardiologist from Paris, presented a case of a 66-year-old woman with lung cancer and a history of thymoma who developed chest pain, diplopia, and ECG abnormalities shortly after receiving anti-PD-1 therapy. She was diagnosed with a syndrome encompassing myocarditis, myositis, and myasthenia-like features. Dr Salem introduced the term myotoxicity to describe this immune-mediated triad, emphasizing that diplopia and cardiac symptoms are highly specific warning signs of such immune-related syndromes. Prompt recognition and management are critical, as these conditions can escalate rapidly.

Neurologist Dr John Probasco from Johns Hopkins discussed a case of immune-related encephalitis, highlighting confusion as a hallmark clinical feature. He stressed the importance of ruling out other causes such as herpes encephalitis or leptomeningeal disease through MRI, lumbar puncture, and antibody testing. Once diagnosed, immune-related encephalitis should be treated with high-dose corticosteroids, followed by a careful taper. Encouragingly, many patients recover well with timely intervention, underscoring the treatability of even severe irAEs when managed appropriately.

The session concluded with a call for close multidisciplinary collaboration between oncologists and organ-specific specialists to ensure early detection and rapid, coordinated treatment of severe toxicities. The interactive discussion with the audience highlighted the growing clinical need for shared expertise and ongoing education in managing complex immunotoxicities, reinforcing the message that integrated care models like BITOX are crucial in improving patient outcomes.