[Effect on Prognosis of Immune-Related Adverse Events after Nivolumab Treatment in Gastric Cancer].

Background The clinical efficacy of nivolumab has been shown as a third-line treatment for advanced gastric cancer; however, nivolumab sometimes causes immune-related adverse events(irAEs). We retrospectively examined the clinical features and influence on treatment in cases of irAEs after nivolumab treatment. Method We retrospectively examined 43 patients who received nivolumab treatment at our institution between October 2017 and December 2019. Result The incidence of irAEs was 23.2%(10/43), and Grade 3 or higher irAEs included interstitial pneumonia, hypoadrenalism, Stevens- Johnson syndrome(SJS), and type 1 diabetes. Three patients showed long-term disease control after irAE onset. Meanwhile, SJS prevented patients from continuing treatment for gastric cancer. Discussion Nivolumab is effective in some patients with gastric cancer, while irAEs made subsequent treatment difficult. Trifluridine/tipiracil or irinotecan are also known to be effective as therapeutic drugs after third-line treatment for gastric cancer in addition to nivolumab; therefore, the choice of the third-line drug and management of irAEs owing to individual cases are considered desirable. Conclusion Long-term efficacy is expected with nivolumab, but it may be necessary to recognize that the onset of serious irAEs might make subsequent treatment difficult.