A Multi-center randomized, double blinded phase IIb trial evaluating oral pooled fecal microbiotherapy MaaT033 to prevent allogeneic hematopoietic cell transplantation complications (The PHOEBUS Trial)

Allogenic haematopoietic cell trasplanation (alloHCT), a procedure consisting of transplanting new blood stem cells from a donor, is a well-established therapy for different life-threatening haematologic malignancies (i.e., blood cancer). The use of alloHCT is constantly increasing. However, common complications following alloHCT include infections and graft-versus-host disease, where the newly received blood stem cells from donor consider one’s own cells as foreign and trigger an immune response to attack their own cells. Studies have shown that strategies aiming to restore gut microbiota composition starting before alloHCT may help prevent this. MaaT Pharma (the Sponsor) is running a research study to see if a test medicine not yet approved for market (MaaT033) will help to prevent complications which may occur after alloHCT, improve survival and how safe it is to use in people. The study is planned to include about 387 participants at least 50 yrs of age who have been diagnosed with haematologic malignancies and are planning to undergo alloHCT. Study participants will be screened, included and randomly assigned in a 1:1 ratio to receive either MaaT033 or placebo, to see if MaaT033 works as well or better than the placebo. MaaT033 is the capsule containing microbiotherapy, the active medicine. The placebo looks like MaaT033 but contains no active medicine and is not expected to have any effect. Participants given MaaT033 or placebo will take 3 capsules per day for 1 wk, 1 to 3 wks before alloHCT. At around 18 days after alloHCT (i.e when patient recovers from neutropenia), participants will continue taking 3 capsules of MaaT033 or placebo up to 90 days after alloHCT. Planned participation in the study is 12-36 mnths.