French biotechnology company MaaT Pharma has reported positive results from an interim safety analysis of its Phase IIb PHOEBUS trial of MaaT033 in subjects undergoing allogeneic haematopoietic stem cell transplantation (allo-HSCT).

The multi-centre, double-blind PHOEBUS trial aims to enrol 387 subjects and will be conducted across up to 60 clinical investigational sites.

Claimed to be the world’s largest randomised controlled study, the trial is comparing the therapy's safety and efficacy in an experimental arm against a placebo in this patient population.

Subjects are currently being enrolled at sites in the Netherlands, Germany, Belgium, Spain, the UK and France.

MaaT Pharma noted that subjects in the early stages after allo-HSCT are extremely vulnerable and experience a non-relapse mortality risk.

Due to this, the trial’s protocol includes a certain safety analysis designed to halt the trial if an excess mortality rate in the experimental arm is detected after 30 subjects have been treated with the therapy and monitored for 90 days following allo-HSCT.

After an unblinded analysis, the Data Safety Monitoring Board (DSMB) has recommended that the study continue according to the plan, as there has been no excessive mortality related to the therapy observed to date.

MaaT Pharma chief medical officer Gianfranco Pittari said: “We are pleased to report that MaaT033’s safety profile continues to be positive.

“The confirmed absence of a pre-specified mortality excess in patients receiving MaaT033 is of critical relevance.

“These patients would enormously benefit from innovative therapies enhancing hematopoietic stem cell transplantation outcomes while avoiding toxic effects.”

The next unblinded interim analysis by the DSMB is scheduled for the third quarter of this year, when the trial has enrolled 120 subjects.

Earlier this year, MaaT Pharma announced the success of its Phase III trial for MaaT013, which met its primary endpoints.