Expanded antigen-specific donor regulatory T cells for GVHD prevention

The authors aimed to evaluate the safety and preliminary efficacy of expanding and infusing minor histocompatibility antigen (mHAg)-specific donor regulatory T cells (Treg) for preventing graft vs. host disease (GVHD) in allogeneic hematopoietic cell transplantation. In a phase I trial involving 15 subjects, they found no dose-limiting toxicities and identified a maximum tolerated dose of 4 x 10^5/kg Treg, with low incidences of acute and chronic GVHD and a 73% overall survival rate at a median follow-up of 41.7 months. The study supports the potential of mHAg-specific expanded donor Treg as a novel strategy for GVHD prevention.