Fecal microbiota transplantation in the treatment of acute graft-versus-host disease: A retrospective study performed by the Complications Working Party and Pediatric Diseases Working Party of the EBMT.

Acute graft-versus-host disease (aGvHD) is a major cause of non-relapse mortality following allogeneic hematopoietic stem cell transplantation (alloHSCT). While corticosteroids are the standard first-line therapy, approximately half of the patients become steroid-refractory or -dependent (SR/D). Fecal microbiota transplantation (FMT) has emerged as a therapeutic strategy targeting the underlying gut dysbiosis associated with aGvHD. This study presents retrospective data on FMT for SR/D-aGvHD. This retrospective, multicenter study was conducted by the Complications Working Party of the EBMT. Data were collected from 9 centers on patients who received FMT for the treatment of SR/D-aGvHD between 2014 and 2019. The primary endpoint was the overall response rate (ORR) at day 28 post-FMT. Forty-seven patients were analyzed. The primary indication for FMT was gastrointestinal aGvHD (GI-aGvHD). In this heavily pre-treated, ruxolitinib-naïve population, the ORR at day 28 was 60.5%, increasing to 69.2% by day 56. At last follow-up, 23 patients (64% of survivors) had no symptoms of aGvHD. Adverse events related to FMT were reported in 24 patients (51.1%). A clinically significant secondary benefit was the 54.5% decolonization rate of antibiotic-resistant bacteria. In this cohort FMT demonstrated efficacy for SR/D-aGvHD, with response rates comparable to those of modern targeted agents.