The real-world efficacy and safety of nivolumab plus chemotherapy in patients with HER2-negative advanced gastric cancer.

Background: The aim of this study is to investigate the real-world efficacy and safety of nivolumab in combination with chemotherapy for patients with advanced human epidermal growth factor receptor 2 (HER2)-negative gastric cancer (GC).

Methods: We enrolled patients diagnosed with unresectable advanced or metastatic GC who received nivolumab plus chemotherapy as first-line systemic treatment. The combined positive score (CPS), indicating the number of programmed cell death-ligand 1 (PD-L1)-stained cells, was utilized. Progression-free survival (PFS) and overall survival (OS) were analyzed using the Kaplan-Meier method. Adverse events (AEs) were graded, and treatment was ceased upon disease progression or intolerance.

Results: A total of 27 patients were included in the study, comprising 15 patients with CPS ≥ 5 and 12 patients with CPS < 5. The objective response rate (ORR) was 55.6%, with a disease control rate (DCR) of 74.1%. Patients in the CPS ≥ 5 group exhibited higher ORR and DCR compared to those in the CPS < 5 group. Median PFS and OS were 6.1 months and 14.6 months, respectively; patients with CPS ≥ 5 showed a trend towards better PFS and OS than those with CPS < 5. Most AEs were grade 1-2, with a few instances of grade 3-4 toxicities reported, including neutropenia, thrombocytopenia, diarrhea, and anemia. There were no grade 5 AEs reported in our cohort. Furthermore, 64.7% of patients received subsequent anticancer treatment following disease progression on nivolumab plus chemotherapy.

Conclusions: The results of our study demonstrate the efficacy and safety of nivolumab plus chemotherapy in real-world practice support its adoption as a new standard first-line treatment for patients with advanced HER2-negative GC, particularly those with CPS ≥ 5.