Research presented at the 63rd American Society of Hematology (ASH) Annual Meeting and Exposition provides more apples-to-apples evidence that matched unrelated donor (MUD) hematopoietic cell transplant (HCT) results in stronger patient outcomes than haploidentical related donor (Haplo) HCT when available.
The study compared outcomes between lymphoma (non-Hodgkin or Hodgkin) patients receiving HCT using either a high resolution 8/8 MUD or haplo using a uniform graft-versus-host disease (GVHD) prevention strategy including post-transplant cyclophosphamide (PTCy).
This was a retrospective study consisting of 2,155 adult patients who received either a first haplo (N=1,843) or MUD (N=312) HCT from 2010-2019 using PTCy. Researchers obtained data from the CIBMTR® (Center for International Blood and Marrow Transplant Research®) and European Bone Marrow Transplant Group (EBMT) research databases. The EBMT study team hypothesized that the use of PTCy would eliminate the advantage between HLA matched and mismatched graft sources.
Patients receiving MUD HCT with PTCy had superior overall survival, progression free survival (stable disease post-HCT and alive), and engraftment (neutrophil and platelet). Post-HCT complications were also lower in the MUD group. Relapse was the only outcome evaluated that was not significantly different between the MUD and haplo groups.
Overall, the research team concluded that patients with lymphoma who underwent MUD transplants had better outcomes than those with haplo transplants. This conclusion held true with and without adjustment for potential confounding variables and controlling for follow-up time after transplantation.
This provides further evidence that when HCT procedures are equivalent, MUD outcomes are superior to haplo. The team recommended, therefore, that if available, MUD should be prioritized over a haplo donor. This study generalizes findings from previous work in acute leukemia and myelodysplastic syndrome across diseases. This data should be used in addition to previous findings to support the continued use of MUD as a superior graft source to haplo.