Efficacy and Safety of Anti-PD-1/anti-PD-L1 Antibody Therapy in Treatment of Advanced Gastric Cancer or Gastroesophageal Junction Cancer: A Meta-analysis

Background: Faced with limited and inadequate treatment options for patients with advanced gastric cancer or gastroesophageal junction cancer (GC/GEJC), researchers have turned toward, with the support of promising clinical trials, anti-PD-1/anti-PD-L1 antibody therapy. But there are also different clinical trial results. To better assess its efficacy and safety, we integrated data from 13 eligible studies for a systematic review and meta-analysis.

Aim: To comprehensively evaluate the efficacy and safety of anti-PD-1/anti-PD-L1 antibody therapy in the treatment of advanced GC/GEJC patients.

Methods: PubMed, Web of Science, Cochrane Library ,and EMBASE databases were searched to identify eligible articles with outcomes including objective response rate (ORR), disease control rate (DCR), overall survival (OS), progression-free survival (PFS), and adverse events (AEs) of anti-PD-1/anti-PD-L1 antibody therapy.

Results: Our study encompassed a total of 13 trials totaling 1618 patients. The outcomes showed a pooled ORR and DCR of 15% (95% confidence interval [CI]: 14%-18%) and 40% (95%CI: 33%-46%), respectively. The pooled 6-mo OS and PFS were 54% (95%CI: 45%-64%) and 26% (95%CI: 20%-32%), respectively, and the 12-mo OS and PFS were 42% (95%CI: 21%-62%) and 11% (95%CI: 8%-13%), respectively. In addition, the incidence of any-grade AEs and grade ≥ 3 AEs was 64% (95%CI: 54%-73%) and 18% (95%CI: 16%-20%), respectively. Most importantly, PD-L1 positive patients exhibited a higher ORR rate than PD-L1 negative patients (odds ratio = 2.54, 95%CI: 1.56-4.15).

Conclusion: Anti-PD-1/anti-PD-L1 antibody therapy has shown promising anti-tumor efficacy with manageable AEs in advanced GC/GEJC patients, with PD-L1 overexpressing patients exhibiting a higher ORR. What is more, the clinical efficacy of anti-PD-1/PD-L1 combined with traditional chemotherapy drugs is even better, although the occurrence of AEs still causes considerate concerns.