MaaT Pharma Seeks Re-Examination After EMA CHMP “Negative Trend” Opinion on Xervyteg for aGvHD

MaaT Pharma, a clinical-stage biotechnology company specializing in microbiome ecosystem therapies, has announced its intention to request a re-examination of its Marketing Authorization Application (MAA) for MaaT013 (Xervyteg) following a “negative trend” opinion from the European Medicines Agency’s (EMA) Committee for Medicinal Products for Human Use (CHMP). The decision comes after the company presented its case during the CHMP’s oral explanation, with the formal vote expected at the June 2026 meeting.

EMA CHMP Feedback and Regulatory Pathway

The CHMP’s “negative trend” opinion highlights challenges associated with first-in-class therapies utilizing novel approaches, particularly those based on single-arm pivotal trials. MaaT Pharma’s application for Xervyteg, a microbiome-based treatment for acute graft-versus-host disease (aGvHD), is being evaluated under the Conditional Marketing Authorization (CMA) pathway. This pathway aims to expedite access to medicines addressing unmet medical needs while post-approval confirmatory data is generated.

“We remain committed to working closely with the EMA to progress this application,” stated Hervé Affagard, CEO and co-founder of MaaT Pharma. “The therapy’s potential to address the significant unmet medical need in patients with aGvHD and the continued support from the hematology community reinforce our belief in MaaT013’s registration potential.”

About Xervyteg: A Microbiome Ecosystem Therapy

Xervyteg (MaaT013) is an off-the-shelf, standardized microbiome therapy designed to restore balance in patients with severe treatment-induced dysbiosis. The therapy leverages a full microbiome ecosystem to modulate immune responses, targeting steroid-resistant gastrointestinal (GI) aGvHD. Key features include:

• High diversity and richness of microbial species
• Presence of Butycore™, a group of bacterial species producing anti-inflammatory metabolites
• Support from clinical data from the pivotal ARES study and real-world evidence from an Early Access Program active in 13 countries

Xervyteg has received Orphan Drug Designations from both the U.S. Food and Drug Administration (FDA) and the EMA, underscoring its potential to address rare diseases with significant unmet needs.

Financial and Pipeline Developments

To align with upcoming regulatory milestones, MaaT Pharma has implemented cash management measures to extend its financial visibility into November 2026. The company continues to advance its pipeline of microbiome-based therapies in oncology, emphasizing its commitment to innovation in immune modulation.

Acute Graft-versus-Host Disease (aGvHD) Context

aGvHD is a severe complication following stem cell or bone marrow transplants, occurring within 100 days of the procedure. It arises when transplanted cells attack the recipient’s organs, leading to inflammation of the skin, liver, and gastrointestinal tract. Current treatments for steroid-resistant aGvHD are limited, with ruxolitinib being the only approved agent in the U.S. And Europe.

FAQ: Key Questions About MaaT Pharma and Xervyteg

What is Xervyteg, and how does it work?

Xervyteg is a microbiome ecosystem therapy designed to restore balance in the gut microbiome, modulating immune responses to address steroid-resistant gastrointestinal aGvHD. It utilizes a standardized, pooled-donor microbiome to correct immune dysfunction.

Why is the EMA’s CHMP opinion significant?

The CHMP’s evaluation determines whether a therapy meets the EMA’s standards for safety, efficacy, and quality. A “negative trend” opinion indicates potential concerns but does not preclude eventual approval, as the company can request a re-examination.

What are the next steps for MaaT Pharma?

The company plans to submit a re-examination request following the June CHMP vote, seeking an independent scientific assessment. This process could extend the regulatory timeline but remains a standard procedure for addressing concerns.

Conclusion: Navigating Regulatory Hurdles in Biotech Innovation

MaaT Pharma’s experience with Xervyteg reflects the complexities of bringing first-in-class therapies to market. While the CHMP’s feedback presents challenges, the company’s commitment to re-examination and its robust clinical data position Xervyteg as a potential breakthrough for aGvHD patients. As the biotech landscape evolves, the interplay between regulatory frameworks and innovation will remain critical in addressing rare and severe diseases.