A retrospective cohort study examining the effects of anti–PD-1 antibody in combination with apatinib in patients previously treated for HER2-negative advanced gastric/gastroesophageal junction cancer.

Abstract

e16048 Background: Combining immune checkpoint inhibitors with vascular endothelial growth factor (VEGF)/VEGF receptor (VEGFR) inhibitors are effective in treating a number of solid tumors; however, evidence in advanced gastric/gastroesophageal junction (G/GEJ) cancer is limited. Methods: This retrospective study included consecutive patients who received a programmed cell death protein 1 (PD-1) inhibitor plus the VEGFR-2 inhibitor apatinib, second-line or later to treat unresectable advanced or metastatic, histologically-proven, human epidermal growth factor receptor 2 (HER2)-negative G/GEJ cancer in a single center between November 1, 2018 and March 31, 2021. Treatment was continued until the disease progressed or the toxicity became intolerable. Results: Data from 52 patients (median age 64 years; 38 men) were analyzed. The primary tumor site was the stomach in 29 patients (56%) and the GEJ in 23 patients (44%). The number of previous line(s) of therapy was one in 22 patients (42%) and two or more in 30 patients (58%). Liver metastasis was present in 22 patients (42%) and 33 patients (63%) had two or more metastatic sites. PD-1 inhibitors taken included camrelizumab (n=28), sintilimab (n=18), pembrolizumab (n=3) and tislelizumab (n=1), all given 200 mg every 3 weeks (Q3W), and toripalimab (240 mg Q3W) and nivolumab (200 mg every 2 weeks) in 1 patient each. The objective response rate was 15.4% (95% confidence interval [CI] 6.9–28.1), the disease control rate was 61.5% (95% CI 47.0–74.7). After a median follow-up of 14.8 months (range 11.8–23.5), median progression-free survival was 4.2 months (95% CI 2.6–4.8), overall survival was 9.3 months (95% CI 7.9–12.9). Grade 3–4 treatment-related adverse events occurred in 12 patients (23.1%). There was no unexpected toxicity or death. Conclusions: Combination therapy with an anti-PD-1 antibody and apatinib was effective in patients with previously treated, unresectable advanced or metastatic G/GEJ cancer, with a manageable safety profile.