Nivolumab Rechallenge After Prior Nivolumab Therapy in Advanced Gastric Cancer: A Single-Center Case Series and Literature Review

Background and Aims Pivotal phase III trials indicated that the anti–PD-1 inhibitor nivolumab prolongs overall survival in patients with advanced gastric cancer. Nivolumab is currently used in the first- or later-line treatment of patients with advanced gastric cancer in Japan. The efficacy of immune check inhibitor rechallenge after progression has been reported in other cancers. Therefore, this study investigated the clinical outcome of nivolumab rechallenge in patients with advanced gastric cancer who received nivolumab in a previous systemic line. Methods We retrospectively reviewed the medical records of six patients with advanced or recurrent gastric cancer who received nivolumab rechallenge. Results During initial nivolumab therapy, three patients experienced partial responses, and one patient achieved stable disease. The reasons for discontinuing initial nivolumab therapy were progressive disease in five patients and immune-related adverse events in one patient. The median interval duration of treatment for patients receiving both nivolumab regimens was 13.7 (range: 5.1–17.8) months. During nivolumab rechallenge, no patients achieved partial responses, whereas two patients had stable disease. Median progression-free survival was 2.5 (95% confidence interval [CI] = 1.6–not available [NA]) months, and median overall survival was 7.4 (95% CI = 2.3–NA) months. Although one patient had discontinued prior nivolumab therapy because of immune-related adverse events, there were no immune-related adverse events associated with nivolumab rechallenge. Conclusions The benefit of nivolumab rechallenge in patients with advanced gastric cancer was limited. Rechallenge with the same immune check inhibitor might be ineffective in patients with advanced gastric cancer.