Fecal microbiota transplant promotes response in immunotherapy-refractory melanoma patients

TLDR

The gut microbiome composition influences cancer patients’ response to immunotherapies. The study aimed to determine whether fecal microbiota transplantation could modify the response of metastatic melanoma patients to anti‑PD‑1 immunotherapy. The authors conducted first‑in‑human trials administering FMT to metastatic melanoma patients undergoing anti‑PD‑1 therapy. Both studies showed clinical benefit in a subset of patients, with increased abundance of taxa linked to anti‑PD‑1 response, heightened CD8⁺ T‑cell activation, and reduced IL‑8‑expressing myeloid cells, demonstrating proof‑of‑concept that FMT can influence immunotherapy response. References include Baruch et al., Davar et al., and Science (this issue, pp.

Abstract

New fecal microbiota for cancer patients The composition of the gut microbiome influences the response of cancer patients to immunotherapies. Baruch et al. and Davar et al. report first-in-human clinical trials to test whether fecal microbiota transplantation (FMT) can affect how metastatic melanoma patients respond to anti–PD-1 immunotherapy (see the Perspective by Woelk and Snyder). Both studies observed evidence of clinical benefit in a subset of treated patients. This included increased abundance of taxa previously shown to be associated with response to anti–PD-1, increased CD8 + T cell activation, and decreased frequency of interleukin-8–expressing myeloid cells, which are involved in immunosuppression. These studies provide proof-of-concept evidence for the ability of FMT to affect immunotherapy response in cancer patients. Science , this issue p. 602 , p. 595 ; see also p. 573