FMT + Anti-PD-1 Delivers 65% ORR and mPFS 29.6 mo in Frontline Melanoma

The MIMic phase I trial (multicenter; NCT03772899) gave a single oral fecal-microbiota transplant (healthy-donor stool) followed by standard anti-PD-1 as first-line therapy for advanced melanoma (n=20). ORR was 65% with mPFS 29.6 months and mOS 52.8 months; 1/2/3-yr OS was 95%/74%/53%, and at analysis 8 were alive, 7 progression-free; treatment was described as safe, and FMT-specific toxicity correlated with longer PFS.These long-run outcomes exceed typical PD-1 monotherapy benchmarks—e.g., nivolumab alone in CheckMate-067: mOS 36.9 months, 6.5-yr OS 43%—and outlast 10-yr OS 34% with pembrolizumab in KEYNOTE-006 (cross-trial differences, selection, and small n apply).