607 MCGRAW trial: evaluation of the safety and efficacy of an oral microbiome intervention (SER-401) in combination with nivolumab in first line metastatic melanoma patients

Microbiome bacterial influencers of host immunity and response to immunotherapy

“…In a recent human trial (NCT03817125), 14 patients with metastatic melanoma were treated with vancomycin followed by a combination of Ruminococcaceae-enriched bacterial communities and anti-PD-1 in the first line setting. 87 Notably, patients in the combination treatment arm experienced a lower objective response rate (25%) than those in the anti-PD-1-only arm (66.7%). These findings imply that previous antibiotic treatments, particularly in the context of limited consortia therapy, might be harmful when patients receive bacterial-based interventions.…”

“… 125 Coriobacteriaceae C. aerofaciens Anti-PD-1 Melanoma Positive Unknown mechanism More abundant in responder patients Davar et al. 52 Bifidobacteriaceae B. adolescentis B. Longum B. Bifidum Anti-PD-1 Melanoma, NSCLC, CRC and RCC Positive Activation of CD8 + T cells, Reduced Tregs activation Diminished tumor advancement Davar et al., 52 Oliva et al., 87 Gao et al., 91 Haikala et al., 131 Han et al. 133 Lactobacillaceae L. reuteri Anti-PD-1 Anti-PDL-1 Melanoma, GI cancers, HCC, NSCLC Positive Improved infiltration of CD8 + T Cells in mice fed with Lactobacillaceae Elevated therapeutic outcomes of ICI treatments Davar et al., 52 Gong et al., 60 Fukuoka et al., 79 Zhao et al., 109 Kawahara et al., 143 Rizvi et al., 145 Gihawi et al.…”

“…These findings imply that previous antibiotic treatments, particularly in the context of limited consortia therapy, might be harmful when patients receive bacterial-based interventions. 87 Therefore, additional research is essential to identify the most effective and safe approach to adjusting the microbiota without risking patients' well-being.…”