Cascade of immunologic adverse events related to pembrolizumab treatment.

Immune checkpoint inhibitors, such as pembrolizumab, have significantly improved cancer patient outcome. Toxicities are usually moderate and manageable. However, some adverse events, if not early recognised, could be life-threatening. We report a patient with non-small cell lung cancer who received treatment with pembrolizumab and developed multiple immune-related adverse events both during and after completing treatment, including rash, pericarditis, colitis and myasthenia gravis.