A large-scale meta-analysis has verified that the gut microbiome does influence patients' response to immune checkpoint inhibitor (ICI) therapy in advanced melanoma, but the relationship appears to be more complex than previously thought.
Overall, researchers identified a panel of species, including Roseburia spp. and Akkermansia muciniphila, associated with responses to ICI therapy. However, no single species was a "fully consistent biomarker" across the studies, the authors explain.
This "machine learning analysis confirmed the link between the microbiome and overall response rates (ORRs) and progression-free survival (PFS) with ICIs but also revealed limited reproducibility of microbiome-based signatures across cohorts," Karla A. Lee, PhD, a clinical research fellow at King's College London, UK, and colleagues report. The results suggest that "the microbiome is predictive of response in some, but not all, cohorts."
The findings were published online February 28 in Nature Medicine.
Despite recent advances in targeted therapies for melanoma, less than half of the those who receive a single-agent ICI respond and those who receive combination ICI therapy often suffer from severe drug toxicity problems. That is why finding patients more likely to respond to a single-agent ICI has become a priority.
Previous studies have identified the gut microbiome as "a potential biomarker of response as well as a therapeutic target" in melanoma and other malignancies, but "little consensus exists on which microbiome characteristics are associated with treatment responses in the human setting," the authors explain.
