MaaT Pharma is a French biotech developing full-ecosystem microbiome therapies. In May 2026 its lead product Xervyteg (MaaT013), for acute graft-versus-host disease, received a 'negative trend' opinion from the EMA's CHMP ahead of a formal vote; its ARES Phase 3 trial showed a 62% gastrointestinal response rate at day 28. Approval after re-examination would make it the world's first approved live biotherapeutic for an oncology indication.