MaaT Pharma announced updated results from its Early Access Program (EAP) of MaaT013, showcasing promising efficacy and safety data in 154 patients with steroid-refractory (SR) or dependent (SD) gastrointestinal acute Graft-versus-Host Disease (GI-aGvHD). The data, selected for poster presentation at the 66th American Society of Hematology (ASH) Annual Meeting, reinforce MaaT013's potential as a transformative therapy for this life-threatening condition. GI-aGvHD is a major complication following allogeneic hematopoietic stem cell transplantation, with limited treatment options for patients who fail initial steroid therapy.
The EAP included patients who had previously failed 1 to 6 lines of systemic treatment for aGvHD, with a significant proportion having grade III (47%) or IV (40%) disease. The results demonstrated robust response rates and sustained survival following MaaT013 treatment.
Efficacy and Survival Outcomes
The full patient cohort (n=154) showed a gastrointestinal overall response rate (GI-ORR) of 51% at day 28, with a complete response (CR) rate of 30% (46 patients). Considering all organs, the ORR was 49%, with a CR rate of 41 patients. Overall survival (OS) was 53% at 6 months, 47% at 12 months, and 42% at 24 months. Notably, OS was significantly higher in patients who responded to MaaT013 compared to non-responders (68% versus 24% at 12 months and 58% versus 24% at 24 months).
Enhanced Response in Ruxolitinib-Experienced Patients
A subset of 58 patients in the EAP, closely resembling the population enrolled in the Phase 3 ARES trial (patients who previously received ruxolitinib), exhibited improved responses compared to the full cohort. In this group, the GI-ORR was 59% at day 28, with a CR rate of 48%. The ORR considering all organs was 55%, with a CR rate of 43%. Consistent with the full cohort, OS was significantly higher in patients who responded to MaaT013 compared to non-responders (75% versus 11% at 12 months and 61% versus 11% at 24 months).
Comparison to Historical Data
Historical data indicates that third-line GI-aGvHD has critically low overall survival rates: 20% at 6 months, 15% at 12 months, and only 10% at 18 months (Abedin et al., 2021). The MaaT013 EAP results suggest a significant improvement in survival outcomes compared to these historical benchmarks.
Anticipated Phase 3 Results
The pivotal Phase 3 ARES trial (NCT04769895), evaluating MaaT013 in GI-aGvHD patients who previously received steroids and ruxolitinib, has been completed in October 2024. Topline results are expected in January 2025. According to Dr. Gianfranco Pittari, MD PhD, Chief Medical Officer of MaaT Pharma, the company is encouraged by these positive long-term results which underscore MaaT013’s potential to address a significant unmet need for patients with refractory GI-aGvHD.
About MaaT013
MaaT013 is an off-the-shelf, standardized, pooled-donor, enema Microbiome Ecosystem Therapy designed for acute, hospital use. It aims to restore the symbiotic relationship between the patient’s gut microbiome and immune system, correcting immune function and reducing steroid-resistant, gastrointestinal (GI)-predominant aGvHD. MaaT013 has been granted Orphan Drug Designation by the FDA and EMA.
