MaaT Pharma to Present Four Abstracts at the 52nd European Bone Marrow Transplantation Annual Meeting and to Highlight Clinigen-Hosted Industry Symposium on acute GvHD Management

• Oral presentation during Presidential Plenary Session to feature the final results of the ARES pivotal Phase 3 trial evaluating MaaT013 in acute Graft-versus-Host Disease (aGvHD) with gastrointestinal involvement
• Poster presentations for:
  • CHRONOS, a multicenter retrospective cohort study describing real-world outcomes in third-line acute gastrointestinal GvHD not treated with microbiotherapy
  • PHOEBUS, a Phase 2b trial, potentially pivotal, evaluating MaaT033 seeking to improve survival after allogeneic hematopoietic transplantation (HCT)
  • THRASSA, a multicenter, open-label paediatric/adolescent study evaluating MaaT013 in patients with ruxolitinib-refractory or ruxolitinib-intolerant gastrointestinal aGvHD
• Clinigen, MaaT Pharma's strategic commercial partner for MaaT013's Early Access Program and commercialization in Europe pending European Medicines Agency (EMA) approval, will host an Industry Symposium on advancing care for steroid-refractory gastrointestinal aGvHD

Regulatory News:

MaaT Pharma (EURONEXT: MAAT the "Company"), a clinical-stage biotechnology company and a leader in the development of Microbiome Ecosystem Therapies^TM (MET) dedicated to enhancing survival for patients with cancer, today announced that clinical data and updates from key programs within its hemato-oncology pipeline will be presented at the 2026 EBMT Annual Meeting, taking place March 22-25, 2026 in Madrid, Spain.

An oral presentation, scheduled during the Presidential Plenary Session, will detail the final results, including overall survival data, from the Company's lead asset MaaT013, which is currently under review by the EMA following the submission of a Marketing Authorization Application in June 2025.

In addition, MaaT Pharma will present three poster communications, featuring:

• Key results from CHRONOS, a multicenter retrospective cohort study describing real-world outcomes in third-line acute gastrointestinal GvHD, and
• The study designs of two clinical trials (PHOEBUS and THRASSA- pediatric study announced in March 2025) advancing the Company's therapeutic pipeline.

With this broad clinical data presentation at the 2026 EBMT Annual Meeting, MaaT Pharma reaffirms its position in hemato-oncology across the full care continuum of HCT and its commitment to improving outcomes for patients undergoing allogeneic transplantation.

During this year's Congress, Clinigen, MaaT Pharma's strategic commercial partner for the MaaT013 product's Early Access Program and commercialization in Europe pending EMA approval, will host a dedicated symposium on Advancing Management of Steroid Refractory aGvHD with GI Involvement: From Unmet Need to a Potential Third Line Option. MaaT013 is currently under regulatory review and not yet approved.

The symposium will be chaired by Florent Malard, MD, PhD, hematology professor at Saint-Antoine Hospital and Sorbonne University and Fabio Ciceri, MD, PhD, Associate Professor of Hematology, University Vita-Salute San Raffaele. It will also feature renowned hematology experts such as Zinaida Peric, MD, hematologist University of Rijeka (Croatia); Chair, GvHD Subcommittee, Transplant Complications Working Party, EBMT, Ernst Holler, Professor at University Medical Center Regensburg (Germany) and Jaime Sanz, MD, hematologist and coordinator of the Bone Marrow Transplant Unit at the University Hospital La Fe in Valencia (Spain). The details of the Symposium are below:

• Title: Advancing Management of Steroid Refractory aGvHD with GI Involvement: From Unmet Need to a Potential Third Line Option.
• Date: Sunday, March 22, 2026
• Time: 12:30 14:00 CET
• Room: N101-102

Professor Malard will also speak at a workshop session dedicated to the Current state of microbiota transplantation in allogeneic HCT, independently from any activities related to the Company, on Monday, March 23, 2026, from 11:00am 11:20am CET in Velazquez location (W02 Workshop GVHD beyond immunosuppression Regulation, repair, and innovation).

EBMT abstracts are now available at www.ebmt.org. Details of the MaaT Pharma presentations are as follow:

Oral presentation:

• Title: MaaT013 for Ruxolitinib-Refractory Acute Graft-versus-Host Disease with Gastrointestinal Involvement: Final Results from the ARES Phase III Trial
• Abstract number: GS2-8
• Session: GS2 Presidential Symposium
• Session Date/Time: Monday, March 23, 2026 17:33 17:42 CET
• Location: VELAZQUEZ
• Presenter: Prof. Malard, MD, PhD, hematology professor at Saint-Antoine Hospital and Sorbonne University and ARES Trial lead investigator

Poster Presentations:

PHOEBUS

• Title: MaaT033 for Gut Microbiota Optimization To Improve Survival after Allogeneic HCT: the Phoebus Trial
• Abstract number: A093
• Session: Transplant and Cellular Therapies Clinical
• Session Date/Time: Monday, March 23, 2026 18:00 19:00 CET
• Location: VELAZQUEZ
• Presenter: Prof. Malard, MD, PhD, hematology professor at Saint-Antoine Hospital and Sorbonne University and PHOEBUS Trial lead investigator

CHRONOS

• Title: Key results from CHRONOS, a multicenter retrospective cohort study describing real-world outcomes in third-line acute gastrointestinal GvHD
• Abstract number: B005
• Session: Graft-versus-Host Disease Clinical
• Session Date/Time: Tuesday, March 24, 2026 18:00 19:00
• Location: VELAZQUEZ
• Presenter: Johannes Clausen, MD, hematologist at Ordensklinikum Linz Elisabethinen, Hematology Department, Linz, Austria

THRASSA

• Title: THRASSA, a Multicenter Open-label Study Evaluating the Safety, Tolerability and Efficacy of MaaT013 in Ruxolitinib-Refractory or Intolerant Paediatric/Adolescent Participants with Gastrointestinal Acute Graft-versus-Host Disease
• Abstract number: P222
• Session: Paediatrics Clinical
• Session Date/Time: Sunday, March 22, 08:30 18:00 CET
• Location: e-Poster area
• Presenter: Marion Bruelle, Clinical Scientist at MaaT Pharma

About MaaT Pharma

MaaT Pharma is a leading, late-stage clinical company focused on developing innovative gut microbiome-driven therapies to modulate the immune system and enhance cancer patient survival. Supported by a talented team committed to making a difference for patients worldwide, the Company was founded in 2014 and is based in Lyon, France. As a pioneer, MaaT Pharma is leading the way in bringing the first microbiome-driven immunomodulator in oncology. Using its proprietary pooling and co-cultivation technologies, MaaT Pharma develops high diversity, standardized drug candidates, aimed at extending life of cancer patients. MaaT Pharma has been listed on Euronext Paris (ticker: MAAT) since 2021.

About Clinigen

Clinigen is a global pharmaceutical services company trusted by over 1,000 pharma and biotech partners. With more than 35 years of experience, we accelerate access to critical medicines at every stage of the product lifecycle. As pathfinders, our team of over 1,100 specialists expertly navigate the complexities of clinical trial supply, early access programs, regulatory services, and long-term commercialisation through both licensed and unlicensed pathways. Operating across five continents, we deliver innovative solutions to over 130 countries each year. Whatever the challenge, we find a way. Explore our services at www.clinigen.com

About MaaT013

MaaT Pharma's Microbiome Ecosystem Therapies (MET) are designed to leverage a full microbiome ecosystem to restore balance and maximize clinical benefits for patients with severe, treatment-induced dysbiosis in acute diseases. MaaT013 is currently under regulatory review by the relevant authorities and has not yet received marketing authorization. MaaT013 is a full-ecosystem, off-the-shelf, standardized, pooled-donors, enema Microbiome Ecosystem Therapy^TM for acute, hospital use. It is characterized by a consistently high diversity and richness of microbial species and the presence of Butycore^TM (a group of bacterial species known to produce anti-inflammatory metabolites). MaaT013 aims to restore the symbiotic relationship between the patient's functional gut microbiome and their immune system to correct the responsiveness and tolerance of immune functions and thus reduce steroid-resistant, gastrointestinal (GI)-aGvHD. MaaT013 has been granted Orphan Drug Designation by the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA).

About MaaT033

MaaT033, a standardized, donor-derived, high-richness, high-diversity oral Microbiome Ecosystem Therapy^TM containing anti-inflammatory Butycore^TM species, is currently being developed as an adjunctive therapy seeking to improve overall survival in patients receiving HSCT and other cellular therapies. Its aim is to seek to optimize microbiota function and to address a larger patient population in a chronic setting. MaaT033 has been granted Orphan Drug Designation by the European Medicines Agency (EMA).

Forward-looking Statements

All statements other than statements of historical fact included in this press release about future events are subject to (i) change without notice and (ii) factors beyond the Company's control. These statements may include, without limitation, any statements preceded by, followed by, or including words such as "target," "believe," "expect," "aim", "intend," "may," "anticipate," "estimate," "plan," "project," "will," "can have," "likely," "should," "would," "could" and other words and terms of similar meaning or the negative thereof. Forward-looking statements are subject to inherent risks and uncertainties beyond the Company's control that could cause the Company's actual results or performance to be materially different from the expected results or performance expressed or implied by such forward-looking statements.

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