[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.