Clinical outcomes and safety analysis for PD-1 inhibitor plus chemotherapy in HER2 negative advanced gastric cancer

Abstract

Abstract Background and purpose: Programmed death-1 (PD-1) inhibitor has been approved as second or later-line treatment in advanced gastric cancer (AGC). The study aimed to compare the clinical outcomes of PD-1 inhibitor plus chemotherapy (combination therapy) with chemotherapy monotherapy as second or later-line treatment in AGC. Methods: The clinical data of patients with AGC with human epidermal growth factor receptor (her2) negative and receiving combination therapy or chemotherapy monotherapyas second or later-line treatment was retrospectively collected. Objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), overall survival (OS) and the occurrence of adverse reactions (AEs) were evaluated between two groups. Result: A total of 107 patients were enrolled in current study. Fifty-seven patients received combination therapy, and fifty patients received chemotherapy monotherapy. After at least 2 cycles of treated, ORR and DCR in combination therapy group were higher than monotherapy group (37.1% vs 4.3%, P<=0.001; 82.3% vs53.2%, P<=0.001). Median PFS and median OS in combination therapy group were significantlly longer than monotherapy group (9.20 months vs 3.07 months, P<=0.001; 10.47 months vs 7.80 months, P<=0.001). The rate of any grade AEs in combination therapy group was significantlly higher than monotherapy group (98.4% vs 85.1%, P=0.024). There was no treatment-related death in two groups. Conclusions: Compared with chemotherapy monotherapy, the PD-1 inhibitor combined with chemotherapy as second or later-line treatment in Her2 negative AGC can prolong OS and PFS and improve DCR. However, the incidence of all AEs in combination therapy group was significantly higher than chemotherapy monotherapy group.