Younger matched unrelated donors provide outcome benefits over older matched siblings for MDS patients undergoing allogeneic transplant

According to the research published in JAMA Oncology, patients with myelodysplastic syndrome (MDS) who received a younger matched unrelated donor allogeneic hematopoietic cell transplant (MUD alloHCT) had favorable relapse and disease-free survival outcomes over those transplanted with older matched sibling donors (MSD). MSD HCT is generally preferred for MDS, even if the donor is older. However, recipients of younger MUD HCT were found to have higher disease-free survival and lower relapse rates than recipients of older MSD HCT with no impact on overall survival rates. Due to the complications of relapse in MDS, this suggests younger MUDs may be a good option when available.

It is often assumed that MSD HCT allows for better outcomes after transplant than other donor types. For older adults with MDS, their siblings are also likely older adults. This observational, retrospective study examined outcomes after transplant for older adults (50 years old or older) with MDS using an older MSD (also 50 years old or older) compared to a younger MUD (35 years old or younger) using the reported data from the CIBMTR® (Center for International Blood and Marrow Transplant Research®).

This study included older adults with MDS who had their first alloHCT between Jan. 1, 2011, and Dec. 31, 2017, with either an older MSD or a younger MUD. Patients who had manipulated grafts were excluded. Additionally, patients receiving post-transplant cyclophosphamide for graft-versus-host disease (GVHD) prevention were excluded.

Most patients underwent alloHCT with peripheral blood grafts, reduced-intensity conditioning, and tacrolimus-based GVHD prevention. Median follow-up was 48.1 months for the MSD cohort and 46 months for the MUD cohort.

The MUD group had a higher disease-free survival rate (30.6% vs. 24.9%) and lower relapse rate (37.3% vs. 49.6%). The MSD group had a lower non-relapse mortality rate (25.5% vs. 32.2%), lower acute GVHD (39.3% vs. 48.3%), and lower chronic GVHD (49% vs. 53.9%).

There is an opportunity to enhance clinical decision-making when choosing donors for patients with MDS. Younger MUDs are associated with good outcomes and should be considered alongside their matched sibling counterparts, especially given the complications of relapse in MDS. Improving survival in older patients with MDS is a notable goal to improve access to transplant, and this study suggests that younger MUD donors should be considered for these patients when available.

Figure 1. Disease-free Survival by Donor Type

Disease-free Survival by Donor Type

Figure 2. Overall Survival by Donor Type

Disease-free Survival by Donor Type

Figure 3. Cumulative Incidence of Relapse

Disease-free Survival by Donor Type

Murthy GSG, et al., published in JAMA Oncology