Response Rate and Prognostic Impact of Salvage Chemotherapy after Nivolumab in Patients with Advanced Gastric Cancer.

Objective: Nivolumab is recommended as a third-line treatment in patients with unresectable advanced or recurrent gastric cancer. Although recent studies have demonstrated the prognostic impact of salvage chemotherapy after immune checkpoint inhibitors in several malignancies, its clinical significance remains unclear in patients with gastric cancer. This study aimed to investigate tumor response to subsequent chemotherapy after nivolumab in patients with advanced gastric cancer and assess the prognostic effect of salvage chemotherapy.

Methods: We retrospectively enrolled 31 patients with unresectable advanced or recurrent gastric cancer receiving nivolumab.

Results: Twenty-two and nine patients received nivolumab as third-line and fourth- to sixth-line treatments, respectively. The objective response rate (ORR) and disease control rate (DCR) to nivolumab were 20.0% (4/20) and 55.0% (11/20), respectively. Eleven patients received salvage chemotherapy after nivolumab. The ORR and DCR to salvage chemotherapy were 37.5% (3/8) and 75.0% (6/8), respectively. The median progression-free survival and overall survival following salvage chemotherapy were 285 and 360 days, respectively.

Conclusion: Our preliminary study indicates that nivolumab exposure may enhance subsequent chemosensitivity in patients with advanced gastric cancer.