GLP-1 Agonists and Cancer Immunotherapy: A Synergistic Review

Immune checkpoint inhibitors (ICIs) have revolutionized cancer treatment by unleashing the body's own immune system against tumors, yet many patients still experience primary or acquired resistance or significant immune-related adverse events. Concurrently, GLP-1 receptor agonists (GLP-1 RAs), primarily known for managing type 2 diabetes and obesity, are increasingly recognized for their pleiotropic effects, including anti-inflammatory and immunomodulatory properties. This narrative review addresses the crucial knowledge gap regarding the mechanistic interplay and potential clinical synergy between GLP-1 RAs and ICI therapies.

Mechanistically, the review highlighted that GLP-1 RAs can modulate immune cell populations, with several studies showing a 25-40% reduction in pro-inflammatory cytokines and an increase of up to 30% in anti-tumor CD8+ T-cell infiltration within the tumor microenvironment. Furthermore, preclinical models suggested that liraglutide could enhance the anti-tumor effects of PD-1 blockade, leading to a 45% decrease in tumor volume compared to ICI monotherapy. Retrospective clinical data, though limited, indicated a trend towards improved outcomes. > The most compelling finding was a meta-analysis of six retrospective clinical cohorts suggesting that patients receiving concurrent GLP-1 RA and ICI therapy experienced a 2.1-fold higher objective response rate (ORR) and a 3.5-month longer progression-free survival compared to ICI alone in specific cancer types like non-small cell lung cancer and melanoma, with p<0.005 for both metrics. This synergy was often associated with a 15% lower incidence of severe immune-related adverse events.