Fecal microbiota transplants help patients with advanced melanoma respond to immunotherapy

Thursday, February 4, 2021

For patients with cancers that do not respond to immunotherapy drugs, adjusting the composition of microorganisms in the intestines — known as the gut microbiome — through the use of stool, or fecal, transplants may help some of these individuals respond to the immunotherapy drugs, a new study suggests. Researchers at the National Cancer Institute (NCI) Center for Cancer Research, part of the National Institutes of Health, conducted the study in collaboration with investigators from UPMC Hillman Cancer Center at the University of Pittsburgh.

In the study, some patients with advanced melanoma who initially did not respond to treatment with an immune checkpoint inhibitor, a type of immunotherapy, did respond to the drug after receiving a transplant of fecal microbiota from a patient who had responded to the drug. The results suggest that introducing certain fecal microorganisms into a patient’s colon may help the patient respond to drugs that enhance the immune system’s ability to recognize and kill tumor cells. The findings appeared in Science on February 4, 2021.

“In recent years, immunotherapy drugs called PD-1 and PD-L1 inhibitors have benefited many patients with certain types of cancer, but we need new strategies to help patients whose cancers do not respond,” said study co-leader Giorgio Trinchieri, M.D., chief of the Laboratory of Integrative Cancer Immunology in NCI’s Center for Cancer Research. “Our study is one of the first to demonstrate in patients that altering the composition of the gut microbiome can improve the response to immunotherapy. The data provide proof of concept that the gut microbiome can be a therapeutic target in cancer.”