BACKGROUND
Our previous retrospective study suggested that peripheral-blood stem-cell infusion before 2:00 p.m. was associated with a lower incidence of acute graft-versus-host disease (aGVHD) than later infusion, but retrospective analyses are susceptible to confounding. Whether infusion timing affects aGVHD has not been tested in a randomized trial.
METHODS
In this multicenter, open-label trial, we randomly assigned patients 12 to 60 years of age with hematologic malignancies undergoing a first allogeneic peripheral-blood stem-cell transplantation to stem-cell infusion at 12:00 pm (±30 minutes) or 6:00 pm (±30 minutes). The primary end point was grade II to IV aGVHD within 100 days after transplantation.
RESULTS
A total of 198 patients underwent randomization (99 in each group). Grade II to IV acute GVHD occurred in 11.1% of patients in the 12:00 pm group and 23.2% in the 6:00 pm group (subdistribution hazard ratio for 6:00 pm vs. 12:00 pm, 2.18; 95% CI, 1.06 to 4.48; P = 0.029). The corresponding incidences of grade III to IV acute GVHD were 2.0% and 12.2% (subdistribution hazard ratio, 6.25; 95% CI, 1.39 to 28.15; P = 0.006). There were no significant differences in hematopoietic recovery, TRM, or relapse between groups.
CONCLUSIONS
Among patients undergoing allogeneic peripheral-blood stem-cell transplantation, infusion at 12:00 pm resulted in a lower incidence of grade II to IV acute GVHD than infusion at 6:00 pm ( ClinicalTrials.gov number, NCT06294678 .)