Immune-related adverse events by immune checkpoint inhibitors

Recent introduction of immune checkpoint inhibitors represented by anti-PD-1 antibodies such as nivolumab and pembrolizumab, and anti-CTLA-4 antibody such as ipilimumab had a great impact on cancer immunotherapy especially for melanoma, non-small cell lung cancer, renal cell carcinoma, and Hodgkin's lymphoma. On the other hand, immune checkpoint inhibitors have their own distinctive adverse events, which are collectively named as "immune-related adverse events". Although immune-related adverse events may occur at any part of the body, interstitial pneumonia, colitis, hypothyroidism, liver dysfunction, skin rash, vitiligo, hypophysitis, type 1 diabetes, renal dysfunction, myasthenia gravis, neuropathy, myositis, and uveitis are representative. The onset of these immune-related adverse events varies. As for ipilimumab, cutaneous and mucous complications appear relatively early, and subsequently digestive symptoms emerge. As for nivolumab, most immune-related adverse events start around a few months after its administration. These immune-related adverse events are basically managed according to the algorism. Prompt consultation to the experts are of great importance and the grade of immune-related adverse events and patients' disease conditions need to be carefully evaluated to decide the optimal measures. As immune-related adverse events could affect various organs, cooperation with many experts from various fields is critical and it is important to organize a cooperative system within a hospital.