FDA declines to free MaaT's microbiome drug from clinical hold after a year

MaaT Pharma is not getting out from under an FDA clinical hold for its microbiome drug any time soon.

MaaT013, in development for steroid-resistant acute graft-versus-host disease (aGvHD), was placed on hold a year ago, halting a phase 3 trial in the U.S. The FDA had concerns about several clinical and manufacturing issues.

Despite requesting a meeting with the agency and submitting detailed responses to the FDA's concerns, MaaT has now heard back that the hold will remain. In an Aug. 8 letter, the FDA said the answers to the original concerns were satisfactory but that it now needs more information on the safety and efficacy of MaaT’s pooling of donor material to standardize the product. The agency also had a couple suggestions on improving the trial design.

MaaT013 is a donor-derived microbiome therapy that provides a group of bacteria to the patient to produce an anti-inflammatory effect. The company collects samples from donors and then mixes them together, or pools them, to achieve a higher richness, diversity and better standardization. The therapy is being assessed in aGvHD patients with gastrointestinal involvement who have tried several previous treatments including steroids and Incyte’s Opzelura.

MaaT was able to launch the European portion of the study, but the U.S. leg has been in limbo. The company submitted the application to start the study in June 2021.

Data from the European cohort suggest MaaT013 has a positive safety and efficacy profile, although MaaT did not provide details.

MaaT is now working on getting in front of the FDA for a meeting to discuss the remaining questions. Development in Europe will continue, and recruitment will be expanded for the phase 3 trial, which currently includes 75 patients. The study has 19 sites in France, Germany and Spain, and applications are pending in three other countries.

At the same time, MaaT is working on getting a phase 2/3 trial going in Europe for its second donor-derived asset, MaaT033, for patients with certain blood cancers who receive stem cell transplants. That study is expected to kick off in the fourth quarter.

The FDA has heavily scrutinized companies working on microbiome therapies. Finch Therapeutics came into hard times after a clinical hold was placed on its donor-derived microbiome drug for Clostridioides difficile in March. Although the hold has been lifted, the company has undergone layoffs and still has some work to do to resume a phase 3 study.

The agency had previously raised concerns about how microbiome companies were screening for COVID-19 infections in donors.