AT A GLANCE

A new study published in Therapeutic Advances in Medical Oncology has determined that the monoclonal antibodies to chemotherapy does not alter the survival benefit among patients with gastric cancer and low programmed death-ligand 1 (PD-L1) expression.¹

"Immune checkpoint inhibitors + chemotherapy became standard HER2− gastric cancer first-line treatment," explain study authors Wang et al. "The aim of this study is to investigate whether immune checkpoint inhibitors + chemo provides benefit for patients with low PD-L1 expression."

For study purposes, the authors searched PubMed, Embase, the Web of Science, and Cochrane Library, along with the 2019–2024 proceedings of the annual meetings of the European Society for Medical Oncology, the American Association for Cancer Research, the American Society of Clinical Oncology (ASCO), and the ASCO Symposium on Gastrointestinal Oncology (ASCO-GI) and the ClinicalTrials.gov database. Phase III randomized controlled trials comparing first-line immunotherapy combined with chemotherapy versus chemotherapy alone in advanced gastric cancer were included. KMSubtraction was used to estimate survival data for those trials that did not report data for the PD-L1 low-expression population.

A total of nine randomized clinical trials were ultimately included. In patients with a combined positive score (CPS) of <1 point or CPS <5 points, monoclonal antibody + chemotherapy did not yield an improvement in overall survival (OS) or progression-free survival (PFS). However, in trials using dual antibodies, patients with a PD-L1 CPS of <5 points achieved improvements in PFS.

Meanwhile, in trials using tumor area positivity (TAP) scoring, the subgroup with TAP < 5% did not achieve benefits in OS or PFS from immunotherapy plus chemotherapy.

"Our study results indicate that, in the first-line treatment of advanced gastric cancer, monoclonal antibody combined with chemotherapy does not provide a survival benefit compared to chemotherapy alone for patients with low PD-L1 expression. However, it is noteworthy that in the COMPASSION-15 trial, patients with CPS < 5 achieve significant improvements in OS and PFS, which may be related to the bispecific antibodies and needs to be validated by further studies," conclude the authors.

Reference

1. Wang Y, Xie T, Xiang S, et al. Comparison of immune checkpoint inhibitors in combination with chemotherapy versus chemotherapy alone in the first-line treatment of advanced gastric cancer patients with low PD-L1 expression: a systematic review and meta-analysis (online ahead of print May 8, 2025). Ther Adv Med Oncol.