PD-1 inhibitor combined with apatinib for advanced gastric or esophagogastric junction cancer: a retrospective study

Background: Nivolumab and pembrolizumab were approved as immune checkpoint inhibitors for third-line treatment of advanced gastric or esophagogastric junction cancer (GC/EGJC) in 2017. However, immunotherapy monotherapy has low efficacy. Apatinib has been proven effective in advanced GC/EGJC. Numerous studies have shown that immunotherapy has a synergistic effect when combined with targeted drug therapy. Based on these facts and to assess the efficacy and safety of programmed death 1 (PD-1) inhibitor and apatinib as combination therapy in patients (pts) with unresectable locally advanced or metastatic GC/EGJC, a retrospective clinical research study was carried out. Methods: Pts (n=24) received PD-1 inhibitor and apatinib (250 mg once daily) as second- or third-line therapy in this observational, retrospective study. The primary objectives were efficacy and safety. Results: At data cut-off (December 31, 2019), 24 pts were enrolled. Of the 19 pts who were evaluable, the objective response rate (ORR) was 26.3% (5/19), the median progression-free survival (PFS) was 3.0 (95% CI: 1.3 to 4.7) months, and the median overall survival (OS) was not reached. Grade 3 or 4 treatment-related adverse events (TRAEs) occurred in 3 (15.8%) of the 19 pts. These adverse events (AEs) included pruritus, rash, hand-foot syndrome, and increased aspartate aminotransferase (AST) or alanine aminotransferase (ALT). No treatment-related deaths occurred. Conclusions: Combination therapy of PD-1 inhibitor and apatinib showed encouraging clinical activity and demonstrated tolerable toxicity in pts with advanced GC/EGJC. Hence, our work provide rationale for the combination of PD-1 inhibitor and apatinib in advanced GC/EGJC.