The following is a summary of “Randomized Double-Blind Phase II Trial of Fecal Microbiota Transplantation Versus Placebo in Allogeneic Hematopoietic Cell Transplantation and AML,” published in the December 2023 issue of Oncology by Rashidi, et al.

For a study, researchers sought to investigate the impact of fecal microbiota transplantation (FMT) on clinical outcomes in allogeneic hematopoietic cell transplantation (HCT) recipients and patients with acute myeloid leukemia (AML). Prior research had demonstrated improvements in microbiome indices following FMT in these populations, but the correlation with clinical outcomes remained uncertain. The study employed a randomized, double-blind, placebo-controlled phase II trial design.

Two cohorts, one comprising allogeneic HCT recipients (74 patients) and the other comprising AML patients undergoing induction chemotherapy (26 patients), were randomized in a 2:1 ratio to receive oral encapsulated FMT or placebo upon neutrophil recovery. The primary endpoint was the all-cause infection rate over 4 months. Patients were monitored for 9 months, and up to three treatments were administered within 3 months after each course of antibacterial antibiotics.

In the HCT cohort, the 4-month infection density was 0.74 in the FMT arm and 0.91 in the placebo arm, resulting in an infection rate ratio of 0.83 (95% CI, 0.48 to 1.42; P = .49). For the AML cohort, the FMT arm exhibited a 4-month infection density of 0.93, while the placebo arm had 1.25, with an infection rate ratio of 0.74 (95% CI, 0.32 to 1.71; P = .48). FMT facilitated postantibiotic recovery of microbiota diversity, restored specific depleted anaerobic commensals, and reduced the abundance of specific expanded genera.

While FMT was deemed safe and effective in ameliorating intestinal dysbiosis, it did not reduce infections in allogeneic HCT recipients and AML patients. The insights gained from the trial will guide future developments in FMT trials.

Source: ascopubs.org/doi/full/10.1200/JCO.22.02366