Assessing the Tolerance and Clinical Benefit of feCAl tranSplantation in patientS With melanOma

Recent studies suggest that patients with metastatic melanoma whose gut microbiome is colonized by eubiotic bacteria have a stronger anti-cancer response to anti CTLA-4 and anti PD1. The hypothesis of this research is that a pooled standardized fecal microbiome transfer (FMT) will shift melanoma patients' gut microbiome towards a composition close to that associated with a better response, and will therefore increase the response to a combination of anti CTLA-4 and anti PD1, without affecting the safety of these drugs. The present trial is the first randomized trial of FMT in patients with unresectable or metastatic melanoma. It will include patients who have neither been exposed to anti CTLA-4 nor anti PD1 or PDL-1, prior to inclusion in the study. The pooled standardized fecal microbiome transfer administered in this study is an experimental drug MaaT013, a microbiome restoration biotherapeutic, produced by MaaT Pharma, and composed of pooled-donor, full-ecosystem intestinal microbiome. The MaaT013 product has a standardized richness (in number of species present) higher than a product obtained from a mono donor (455 species approximately against 274 on average) and contains bacteria species (mentioned in the rationale) associated with better response to anti- CTLA-4 and anti PD1.