Biological Agents for Treating Atezolizumab-Induced Psoriasis in Small-Cell Lung Cancer: A Case Report

One of the immune-related adverse events from immune checkpoint inhibitors (ICIs) is skin toxicity. Oral corticosteroids are the first-line treatment for severe cutaneous immune-related adverse events. However, corticosteroids may conflict with the efficacy of ICIs. A 55-year-old Japanese man with a history of psoriasis vulgaris was diagnosed with small-cell lung cancer (Stage ⅣA) and administered combined chemoimmunotherapy, including atezolizumab, which resulted in exacerbation of psoriasis. In response, he was treated with biological agents, such as anti-IL-23 and IL-17 antibodies, risankizumab, and secukinumab, respectively, and achieved long-term survival with continued treatment with atezolizumab. This case report suggests that biological agents might be the best course of treatment against autoimmune-related adverse events caused by ICI therapy.