Updated comparable efficacy of cord blood transplantation for chronic myelomonocytic leukaemia: a nationwide study.

Chronic myelomonocytic leukaemia (CMML) is a haematological malignancy with a poor prognosis. Allogeneic haematopoietic stem cell transplantation remains the only curative approach. Without human leucocyte antigen-matched related sibling donors, the optimal alternative donor has yet to be established. Although unrelated bone marrow transplantation (UBMT) has been extensively studied, cord blood transplantation (CBT) for CMML remains largely unexplored. This nationwide retrospective study compared the outcomes of UBMT and single-unit umbilical CBT in patients with CMML. This study included 118 patients who underwent their first allo-HSCT during 2013-2021. Of these, 50 received BMT (UBMT group), while 68 underwent CBT (CBT group). The primary endpoint was the 3-year overall survival (OS). There were comparable 3-year OS rates between the UBMT (51.0%, 95% confidence interval [CI]: 34.1-65.5%) and CBT (46.2%, 95% CI: 33.2-58.1%; P = 0.60) groups. In the inverse probability of treatment weighting analysis, CBT did not show significantly improved outcomes compared with UBMT regarding the 3-year OS rate (hazard ratio 0.97 [95% CI: 0.57-1.66], P = 0.91). Thus, CBT may serve as an alternative to UBMT for patients with CMML. Further research is necessary to optimise transplantation strategies and enhance outcomes in patients with CMML undergoing CBT.