Evaluating antithymocyte globulin in preventing graft-versus-host-disease after matched sibling donor transplantation

This study aimed to investigate the role of antithymocyte globulin in preventing graft-versus-host disease after matched sibling donor transplantation. 

This study concluded that this treatment can reduce the occurrence of graft-versus-host-disease in these patients.  

One treatment option for patients with blood cancers is stem cell transplantation (SCT). HLA-matched sibling donor transplantation (MSDT) is where stem cells are donated from a sibling and transplanted to the patient. The transplant aims to boost the immune system and replace cells damaged by other cancer treatments.  

Graft-versus-host-disease (GVHD) can occur after transplant. This is a complication where the transplanted cells attack and damage the patient's body. This is the main cause of death or side effects in patients after transplant. Therefore, treatments that interfere with the immune response such as cyclosporine (CsA; Gengraf), methotrexate (MTX; Otrexup), or mycophenolate mofetil (MMF; CellCept) are needed to prevent GVHD.

Antithymocyte globulin (ATG; Thymoglubulin) is a drug that suppresses the immune system. It is used to prevent and treat transplant rejection. The safety and effectiveness of ATG in preventing GVHD after MSDT are still unknown.

This study involved 263 patients with leukemia or lymphoma who underwent MSDT. Patients were assigned to receive CsA, MTX, and MMF with or without ATG. The main outcome measured was acute (short-term) GVHD on day 100 after transplant.  

The rate of short-term GVHD was 13.7% for the ATG group compared to 27% for the control group. The 2-year occurrence of chronic (long-term) GVHD was 27.9% for the ATG group compared to 52.5% for the control group. The 2-year occurrence of extensive chronic GVHD was 8.5% for the ATG group compared to 23.2% for the control group.  

2 years after transplant, 84.8% in the ATG group and 57.4% in the control group were free from immunosuppressant therapy. 

There were no differences between the two groups in relation to infections, relapse rate, and 3-year overall survival. The 3-year GVHD relapse-free survival (RFS) was 38.7% for the ATG group compared to 24.5% for the control group. 

This study concluded that ATG can decrease the risk of GVHD after MSDT.