Association Between Immune-Related Adverse Events and the Prognosis of Patients with Advanced Gastric Cancer Treated with Nivolumab

Little is known about the association between immune-related adverse events (irAEs) and the efficacy and survival outcomes of nivolumab in patients with advanced gastric cancer (AGC). The present study examined the association between irAEs and the prognosis of patients with AGC treated with nivolumab. From July 2017 to November 2020, patients who had been diagnosed with advanced unresected gastric cancer and treated with nivolumab at our institution were included in this analysis. We compared the clinical and survival outcomes between the irAE and non-irAE groups. We also evaluated the factors associated with better survival in patients treated with nivolumab. A total of 52 patients were included in the present study, and irAEs were observed in 13 (25%). Among the patients with measurable lesions (n = 29), the disease control rates were significantly higher in the irAE group than in the non-irAE group (88 vs. 24%; P = 0.0033). At the 8- and 12-week landmark analyses, the median overall survival (OS) in the irAE group was significantly longer than that in the non-irAE group, whereas the median progression-free survival was comparable between the groups. A multivariate analysis by Cox proportional hazard regression at the 8-week landmark revealed that the development of irAEs (hazard ratio 0.18; 95% confidence interval 0.0099–0.86) alone was positively associated with a longer OS. The development of irAEs might be associated with survival outcomes with nivolumab treatment in patients with AGC.