ABSTRACT
Selecting the most suitable alternative donor becomes challenging in severe aplastic anemia (SAA) when a matched sibling donor (MSD) is unavailable. We compared outcomes in SAA patients undergoing SCT from matched unrelated donors (MUD, n=1106), mismatched unrelated donors (MMUD, n=340), and haploidentical donors (Haplo, n=206) registered in the EBMT database (2012-2021). For Haplo-SCT, only those receiving post-transplant cyclophosphamide (PT-Cy) for graft-versus-host disease (GVHD) prophylaxis were included. Median age was 20 years, and the median time from diagnosis to transplantation 8.7 months. Compared to MUD, MMUD (HR, 2.93; 95% CI, 1.52-5.6) and Haplo (HR, 5.15; 95% CI, 2.5-10.58) showed significantly higher risks of primary graft failure. MUD had lower rates of acute GVHD compared to MMUD and Haplo, grade II-IV (13%, 22%, and 19%, respectively, p<0.001) and III-IV (5%, 9%, and 7%, respectively, p=0.028). The 3-year non-relapse mortality was 14% for MUD, 19% for MMUD, and 27% for Haplo (p<0.001), while overall survival (OS) and GVHD and relapse-free survival (GRFS) were 81% and 73% for MUD, 74% and 65% for MMUD, and 63% and 54% for Haplo, respectively (p<0.001). In addition to donor type, multivariable analysis identified other factors like patient age, performance status, and interval between diagnosis and transplant associated with GRFS. For SAA patients lacking an MSD, our findings support MUD transplantation as the preferable alternative donor. However, selecting between a MMUD or Haplo donor remains uncertain and requires further exploration.
ABSTRACT
WHAT IS THIS SUMMARY ABOUT?: Severe aplastic anemia (SAA) and very severe aplastic anemia (vSAA) are blood diseases of the bone marrow. If a suitable donor for bone marrow transplant as initial treatment is unavailable, standard immunosuppression is used. Standard immunosuppression treatment includes horse antithymocyte globulin (hATG) and cyclosporin A (CsA). This summary investigated the results of standard immunosuppression treatment (Group A) versus standard immunosuppression treatment with a medication called eltrombopag (Group B) in participants with SAA and vSAA. Eltrombopag is a medicine that improves the blood platelet level and is taken by mouth (orally). WHAT WERE THE RESULTS OF THE STUDY?: Compared to Group A, more participants in Group B showed increased blood cell level to a normal range without SAA or vSAA and faster treatment response. Side effects were similar in both groups even with the addition of eltrombopag for Group B. Participants in both groups reported feeling well after 6, 12 and 24 months. Differences in the participant-reported scores (overall health, physical, emotional, and social) between Group A and Group B were minimal. WHAT DO THE RESULTS OF THE STUDY MEAN?: Immunosuppression treatment (hATG plus CsA) with eltrombopag benefited participants with SAA and vSAA and could be the new standard for SAA in persons who cannot undergo bone marrow transplant. At this time, eltrombopag is only approved in specific countries to treat the condition under study that is discussed in this summary. Clinical Trial Registration: NCT02099747 (RACE study).
