A win ratio approach for comparing graft‐versus‐host disease‐free, relapse‐free survival among alternative donors

Summary The optimal alternative donor type for patients lacking human leucocyte antigen (HLA)‐matched related or unrelated donors remains unclear. In comparative studies evaluating donor types, graft‐versus‐host disease (GVHD)‐free, relapse‐free survival (GRFS) represents a well‐established end‐point but has limitations. The win ratio approach addresses these limitations by analysing multiple end‐points with varying severities to account for the relative component priorities. We compared HLA‐mismatched unrelated donors, haploidentical donors and cord blood using both the hazard ratio (HR) of GRFS and the win ratio related to GRFS. The haploidentical donor group had a similar HR of GRFS (HR: 1.01, 95% confidence interval [CI]: 0.85–1.19, p = 0.916) and win ratio (win ratio: 0.86, 95% CI: 0.72–1.02, p = 0.081) to HLA‐mismatched unrelated donors. Cord blood transplantation showed similar GRFS compared to HLA‐mismatched unrelated donors in the Cox proportional model (HR: 1.14, 95% CI: 0.98–1.32, p = 0.085), significantly lower win ratio (win ratio: 0.80, 95% CI: 0.68–0.93, p = 0.004) and similar outcomes to haploidentical donors. HLA‐mismatched unrelated donor transplantation showed comparable to superior outcomes among alternative donor types. Our results indicate the need to present the win ratio alongside conventional methods to assess the end‐point robustly.