Effect of graft-versus-host disease on outcomes of HLA-haploidentical peripheral blood transplantation using post-transplant cyclophophamide

There is limited evidence regarding the association between graft-versus-host disease (GVHD) and reduced relapse in patients who undergo allogeneic hematopoietic stem cell transplantation from haploidentical donors (haplo-HSCT) using post-transplant cyclophosphamide (PTCY). We investigated the association between GVHD and transplant outcomes in 938 patients who received haplo-HSCT using PTCY. Overall survival (OS), relapse rate, and non-relapse mortality (NRM) were evaluated using landmark analysis at the landmark points at 100 and 360 days after HSCT for acute and chronic GVHD, respectively. Grade I–II acute GVHD was not associated with OS (adjusted hazard ratio: 1.15, 95% confidence interval: 0.85–1.57), relapse (1.03, 0.74–1.45) and NRM (1.15, 0.74–1.77). Conversely, grade III–IV acute GVHD was associated with higher NRM (3.16, 1.61–6.19), but no other outcomes. Limited chronic GVHD was not associated with OS (1.11, 0.48–1.95), relapse (1.05, 0.30–3.75) and NRM (1.30, 0.45–3.79). Extensive chronic GVHD was associated with higher NRM (2.40, 1.03–5.57), but no other outcome. In conclusion, any GVHD was not associated with a reduced relapse rate and improved OS, and Grade III–IV acute GVHD and extensive chronic GVHD were associated with higher NRM in patients who received haplo-HSCT using PTCY.