Contributions
Abstract: PB1840
Type: Publication Only
Background
Severe aplastic anemia (SAA) is a life-threatening disorder characterized by pancytopenia in the peripheral blood and hypocellular marrow. Although both allogeneic hematopoietic stem cell transplantation (HSCT) and immunosuppressive treatment (IST) are available treatments, allogeneic HSCT from a HLA-matched familial donor is preferred by SAA patients. However, approximately two-thirds of patients do not have a suitable HLA-matched sibling donor; therefore, either IST or alternative donor HSCT is employed in such cases. However, previous reports have shown that IST is related with a substantial risk of relapse and clonal evolution. Furthermore, IST often leads to the amelioration of cytopenia rather than cures. Advances in HSCT, such as modification of the conditioning regimen, a better selection of donors by high degree HLA allele level matching and the introduction of low-dose TBI, have improved the outcomes of HSCT in patients with SAA.
Aims
The aim of our study was to compare the outcomes of immunosuppressive treatment (IST) and hematopoietic stem cell transplantation (HSCT) as frontline therapy in young adults with severe aplastic anemia (SAA).
Methods
We retrospectively reviewed the medical records of 24 patients with acquired severe aplastic anemia (SAA). Eleven patients received immunosuppressive treatment (IST) and 13 patients received hematopoetic stem cell transplantation (HSCT) from matched related or unrelated, or alternative donor as a frontline therapy. SAA was defined according to the standard criteria; if patients met these criteria and had a neutrophil count <0.2 × 109/L, their disease was considered to be very severe aplastic anemia. To assess the effect of treatment modalities on the outcomes, the probable overall survival (OS), failure - free survival (FFS) or event - free survival (EFS) rates were estimated. Complete response was defined as a normal hemoglobin level for age, neutrophil count >1.5 × 109/L and platelet count >150 × 109/L. Partial response was defined as transfusion independent and no longer meets the criteria for severe disease. Treatment failure or an event after HSCT was defined as death, primary graft failure, late rejection, relapse and secondary malignancy, whichever occurred first.
Results
Sex, age and the disease status at treatment were comparable between the 2 groups; however, the median time from diagnosis to treatment was longer in the frontline HSCT group than in the frontline IST group (10.1 months vs 4.0 months respectively, P=0.025). The overall response rate of IST was 42.1%. Among the 13 patients who underwent frontline HSCT, 11 experienced FFS. Although the 5-year OS was comparable between the frontline HSCT and frontline IST groups (91.3% vs 71.2% respectively, P=0.187), the 5-year FFS was significantly higher in the former than the latter (91.3% vs 30.7% respectively, P<0.001).
Conclusion
Both IST and alternative donor HSCT have improved the survival rate of patients with SAA. Our data suggests that frontline HSCT may be a better treatment option than IST for young adults especially in situations where ATG is not available.
Session topic: 12. Bone marrow failure syndromes incl. PNH - Clinical
Keyword(s): Hematopoietic cell transplantation, Aplastic anemia, Immunosuppressive therapy
Abstract: PB1840
Type: Publication Only
Background
Severe aplastic anemia (SAA) is a life-threatening disorder characterized by pancytopenia in the peripheral blood and hypocellular marrow. Although both allogeneic hematopoietic stem cell transplantation (HSCT) and immunosuppressive treatment (IST) are available treatments, allogeneic HSCT from a HLA-matched familial donor is preferred by SAA patients. However, approximately two-thirds of patients do not have a suitable HLA-matched sibling donor; therefore, either IST or alternative donor HSCT is employed in such cases. However, previous reports have shown that IST is related with a substantial risk of relapse and clonal evolution. Furthermore, IST often leads to the amelioration of cytopenia rather than cures. Advances in HSCT, such as modification of the conditioning regimen, a better selection of donors by high degree HLA allele level matching and the introduction of low-dose TBI, have improved the outcomes of HSCT in patients with SAA.
Aims
The aim of our study was to compare the outcomes of immunosuppressive treatment (IST) and hematopoietic stem cell transplantation (HSCT) as frontline therapy in young adults with severe aplastic anemia (SAA).
Methods
We retrospectively reviewed the medical records of 24 patients with acquired severe aplastic anemia (SAA). Eleven patients received immunosuppressive treatment (IST) and 13 patients received hematopoetic stem cell transplantation (HSCT) from matched related or unrelated, or alternative donor as a frontline therapy. SAA was defined according to the standard criteria; if patients met these criteria and had a neutrophil count <0.2 × 109/L, their disease was considered to be very severe aplastic anemia. To assess the effect of treatment modalities on the outcomes, the probable overall survival (OS), failure - free survival (FFS) or event - free survival (EFS) rates were estimated. Complete response was defined as a normal hemoglobin level for age, neutrophil count >1.5 × 109/L and platelet count >150 × 109/L. Partial response was defined as transfusion independent and no longer meets the criteria for severe disease. Treatment failure or an event after HSCT was defined as death, primary graft failure, late rejection, relapse and secondary malignancy, whichever occurred first.
Results
Sex, age and the disease status at treatment were comparable between the 2 groups; however, the median time from diagnosis to treatment was longer in the frontline HSCT group than in the frontline IST group (10.1 months vs 4.0 months respectively, P=0.025). The overall response rate of IST was 42.1%. Among the 13 patients who underwent frontline HSCT, 11 experienced FFS. Although the 5-year OS was comparable between the frontline HSCT and frontline IST groups (91.3% vs 71.2% respectively, P=0.187), the 5-year FFS was significantly higher in the former than the latter (91.3% vs 30.7% respectively, P<0.001).
Conclusion
Both IST and alternative donor HSCT have improved the survival rate of patients with SAA. Our data suggests that frontline HSCT may be a better treatment option than IST for young adults especially in situations where ATG is not available.
Session topic: 12. Bone marrow failure syndromes incl. PNH - Clinical
Keyword(s): Hematopoietic cell transplantation, Aplastic anemia, Immunosuppressive therapy