Clinical-stage biotechnology company MaaT Pharma (Euronext Paris:MAAT) announced on Tuesday that an independent Data Safety Monitoring Board has recommended the continuation of its Phase 2b PHOEBUS trial evaluating MaaT033, following a scheduled unblinded interim safety analysis.

The decision confirms the absence of excessive mortality in patients receiving the treatment after allogeneic haematopoietic stem cell transplantation (allo-HSCT).

MaaT033, a donor-derived oral microbiome therapy, continues to show a favourable safety and tolerability profile in this high-risk patient group. The review was triggered after 30 patients in the experimental arm had completed a 90-day post-transplant follow-up, representing half of the approximately 60 patients enrolled to date.

This positive outcome reinforces MaaT033's safety and supports its ongoing integration into the allo-HSCT care setting. The trial remains on track to enrol up to 387 patients across 60 clinical sites in France, Germany, Belgium, Spain, the Netherlands and the UK.

The PHOEBUS trial is the largest randomised study of microbiome therapy in oncology to date, comparing MaaT033 to placebo. The next DSMB interim analysis is scheduled for the third quarter of 2025, following enrolment of 120 patients.