Pivotal Phase 3 Trial Results Mark Major Advancement

On March 18, MaaT Pharma announced that its pivotal Phase 3 ARES trial evaluating MaaT013—a donor-derived microbiome ecosystem therapy—for patients with gastrointestinal acute graft-versus-host disease (GI-aGvHD) met its primary endpoint. The final Data Safety Monitoring Board (DSMB) review confirmed notable efficacy and a positive benefit/risk profile in severely ill, steroid- and ruxolitinib-refractory patients.

Key Study Highlights

• The DSMB confirmed an overall GI response rate at Day 28 of 62%, far exceeding the expected 38% benchmark, based on a full safety review of 66 patients.
• Safety data affirmed an acceptable profile, with no new signals identified.
• MaaT013, given as a third-line therapy, significantly improved outcomes for this high-mortality population.

Chief Medical Officer Dr. Gianfranco Pittari stated the findings “validate MaaT013’s consistently favorable clinical profile, demonstrated over years in a highly fragile patient population.” CEO Hervé Affagard confirmed plans to submit the marketing authorisation application to the European Medicines Agency in June 2025.

Positioning and Regulatory Timeline

The company also received the green light for its Pediatric Investigation Plan (PIP) from the EMA Pediatric Committee. Evaluation of long-term (one-year) overall survival is ongoing, with results expected Q4 2025.

If approved, MaaT013 would become Europe’s first microbiome-based therapeutic for this indication, opening the door to a novel class of gut-microbiome modulators in immunocompromised patients.

Outlook: Innovation in Microbiome and Cell Therapy for Cancer Patients

MaaT Pharma’s advance exemplifies the growing momentum behind live biotherapeutics for cancer complications and immune disorders. Analysts predict that successful regulatory review would catalyze broader acceptance of microbiome ecosystem therapies worldwide, with MaaT013 as the category’s likely trailblazer.