Anti-PD-1 response restored after introduction of diverse microbiome in murine model... https://seekingalpha.com/pr/17132215-seres-therapeutics-presents-new-preclinical-data-supporting-development-microbiome Seres Therapeutics Presents New Preclinical Data Supporting the Development of Microbiome Therapeutics for Immuno-Oncology Seres presented results from preclinical studies designed to evaluate the impact of various consortia of bacterial species on the anti-tumor immune response in murine models following treatment with an anti-PD-1 checkpoint inhibitor. Results demonstrated that both germ-free mice lacking a microbiome and antibiotics-treated mice with a dysbiotic microbiome, failed to mount an effective anti-tumor response following treatment with an anti-PD-1 checkpoint inhibitor. The response to anti-PD-1 was restored in germ-free as well as antibiotics-treated mice by introducing a diverse microbiome, and was driven by increased entry of tumor-infiltrating lymphocytes into the tumor; specifically, CD8+ T effector cells. Current pre-clinical efforts are focused on optimizing specific microbiome compositions based on functional and phylogenetic information to inform the development of therapeutic candidates.