Researchers analyzing the outcomes of 1,000 patients with sickle cell disease (SCD) who underwent identical sibling hematopoietic cell transplantation (HCT) between 1986 and 2013 characterized the 5-year survival as “excellent” and concluded that their results “confirm this is an accepted treatment for severe SCD.”
Five-year overall survival (OS) for all transplant recipients was 92.9% and event-free survival (EFS) was 91.4%. The 5-year OS was 95% for patients aged <16 years and 81% for those aged ≥16 years (p<0.001). The 5-year probability of GVHD-free survival was 86% and 77% for patients aged <16 and ≥16 years, respectively (p<0.001).
Five-year EFS was significantly higher for transplants performed after 2006 (HR 0.95, p=0.013) and lower with increased age at the time of HCT (HR 1.09, p<0.001).
The median age at transplantation was 9 years and the median follow-up for surviving patients was 55 months (range, 3-325). The most frequent indications for HCT included stroke, acute chest syndrome, and recurrent vaso-occlusive disease. Patients were transplanted in the United States (n=439), in Europe (n=513) and in non-European countries (n=48). Outcomes were reported to the European Society for Blood and Marrow Transplantation (EBMT), Eurocord and CIBMTR® (Center for International Blood and Marrow Transplant Research®).
This study confirmed that age is a significant prognostic factor for HCT outcomes. The researchers concluded that the findings support the need for early referral of patients with SCD for allogeneic transplantation in order to initiate HCT from an HLA-identical sibling in a timely manner and potentially reduce acute GVHD risks associated with increased age at HCT.