# Faecal microbiota transplantation for PD-1 non-responders

Source: https://onco.cc/technologies/fmt-checkpoint-nonresponders/  
OnCo record `fmt-checkpoint-nonresponders` (Technology). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Transplanting gut bacteria from patients who responded to immunotherapy into those who did not. In small studies a minority of resistant melanomas started responding. Randomised trials are running.

## Summary

Two single-arm phase 1 studies published together in Science in 2021 (Pittsburgh, NCT03341143; Sheba, NCT03353402) gave responder-derived faecal microbiota transplantation (FMT) plus anti-PD-1 to patients with anti-PD-1-refractory melanoma: 6 of 15 and 3 of 10 patients had clinical benefit, with increased CD8 infiltration and engraftment of donor taxa. In the first-line setting, MIMic-01 (Montreal, NCT03772899, Nature Medicine 2023) combined healthy-donor FMT with anti-PD-1 in 20 patients and reported a 65% objective response rate, above historical controls. Randomised phase 2 trials are now running in Canada, Norway and the Netherlands using capsule FMT, and defined bacterial consortia and single-strain products (for example, CBM588, Akkermansia) are in development as a more controllable alternative. Donor screening, transmission risk and lack of a validated 'good microbiome' signature remain the problems.

## Fields

- Kind: Technology
- Status: phase-2
- Last checked: 2026-09-08
- Principle: Replacing a non-permissive gut community with a responder-derived one restores microbial signals (metabolites, pattern-recognition ligands) that prime dendritic cells and systemic anti-tumour T-cell immunity.
- Strengths: Responses in genuinely refractory patients; Agnostic to tumour genotype; Cheap relative to drugs
- Limitations: Single-arm studies, small numbers; Donor variability and safety (screening for pathogens); Antibiotics, diet and proton-pump inhibitors confound everything

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Fecal_microbiota_transplant
- Davar et al. (Science 2021): https://doi.org/10.1126/science.abf3363
- Routy et al. MIMic-01 (Nat Med 2023): https://doi.org/10.1038/s41591-023-02453-x

## Connected records

- ideas: [Microbiome transplant as a routine immunotherapy adjunct](https://onco.cc/ideas/idea-microbiome-io-fmt/), [Take faecal transplant plus immunotherapy to a definitive trial](https://onco.cc/ideas/idea-bio2-fmt-plus-checkpoint-phase3/)
- cancers: [Advanced melanoma (unresectable stage III and stage IV)](https://onco.cc/cancers/advanced-melanoma/), [Melanoma](https://onco.cc/cancers/melanoma/), [Non-small-cell lung cancer](https://onco.cc/cancers/nsclc/), [Renal cell carcinoma](https://onco.cc/cancers/rcc/)
- fronts: [Diet, Exercise & Lifestyle](https://onco.cc/fronts/nutrition-lifestyle/), [Immunotherapy](https://onco.cc/fronts/immunotherapy/)
- technologies: [Dietary fibre and the gut microbiome for immunotherapy response](https://onco.cc/technologies/dietary-fibre-microbiome-io/), [Immune checkpoint inhibitors](https://onco.cc/technologies/checkpoint-inhibitor/), [Microbiome modulation to unlock immunotherapy](https://onco.cc/technologies/microbiome-modulation-io/)
- drugs: [Nivolumab](https://onco.cc/drugs/nivolumab/), [Pembrolizumab](https://onco.cc/drugs/pembrolizumab/)
- pathways: [Microbiome-tumour interactions](https://onco.cc/pathways/microbiome-tumour/)
- terms: [Gut microbiome diversity and composition](https://onco.cc/terms/gut-microbiome-diversity/)
- trials: [FMT plus pembrolizumab in anti-PD-1-refractory melanoma (Pittsburgh)](https://onco.cc/trials/fmt-pd1-refractory-melanoma-pitt/), [MIMic-01: healthy-donor FMT plus anti-PD-1, first-line melanoma](https://onco.cc/trials/mimic-01/)
- people: [Laurence Zitvogel](https://onco.cc/people/laurence-zitvogel/)
- bottlenecks: [No one can predict who responds to immunotherapy](https://onco.cc/bottlenecks/b-immunotherapy-response/)
- key papers: [Fecal microbiota transplant overcomes resistance to anti-PD-1 therapy in melanoma patients](https://onco.cc/key-papers/paper-davar-science/)
- roadmaps: [Diet, exercise and lifestyle roadmap: causes established → interventions that disappointed → exercise proven as treatment](https://onco.cc/roadmaps/nutrition-lifestyle-roadmap/)

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