MaaT Pharma Announces Positive Second Safety Interim Analysis from DSMB for Phase 2b PHOEBUS Trial Evaluating MaaT033 for Patients Receiving Allo-HSCT

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 through immune modulation, announced that the independent Data Safety Monitoring Board (DSMB) has completed the second pre-planned safety interim analysis of the ongoing PHOEBUS trial, a Phase 2b randomized controlled trial designed to be pivotal, evaluate the efficacy and safety of MaaT033 versus placebo in patients undergoing an Allogeneic Hematopoietic Stem Cell Transplantation (allo-HSCT). The PHOEBUS trial is the world’s largest randomized controlled trial evaluating microbiome therapy in oncology to date.

“We are pleased to report another positive safety review for MaaT033 with the DSMB’s recommendation to continue the trial without modification marking a key milestone in its development. We remain fully committed to advancing this Phase 2b trial and to delivering a much-needed therapeutic option for patients fighting blood cancers and undergoing allo-HSCT and to shaping a future where microbiome-based therapies become an integral part of hematology-oncology treatment,” said Hervé Affagard, Chief Executive Officer and co-founder of MaaT Pharma.

The DSMB reviewed unblinded safety data on 120 enrolled patients (including 60 patients randomized to receive MaaT033) and monitored patients for 90 days after allo-HSCT as per the trial protocol. Patients are especially vulnerable in the early phase after allo-HSCT, with a heightened risk of non-relapse mortality. To ensure patient safety, the study protocol includes a predefined safety review, with a stopping rule if an excess of mortality is detected in the experimental group.

Following its review, the DSMB recommended that the study continue as planned, having identified no safety concerns and no excessive mortality related to MaaT033 as of today.

In addition to this specific safety analysis, routine safety assessments are conducted every six months. All assessments to date have confirmed a favorable safety profile for MaaT033, and recommended continuation of the trial without modifications. These regular safety reviews further support MaaT033’s integration in the allo-HSCT treatment setting, without significant added risk of severe adverse events.