From the Guidelines
The use of Anti-Thymocyte Globulin (ATG) in Autologous Stem Cell Transplantation (ASCT) is not a standard practice, but it can be used in certain cases, such as in patients with steroid-refractory acute Graft-Versus-Host Disease (aGVHD) [ 1 ].
ATG Dosing Regimen
The dosing regimen of ATG typically involves administering a dose of 1.5 to 2.5 mg/kg/day for 2-4 days, often in combination with other immunosuppressive agents such as cyclosporine and methotrexate [ 1 ].
ATG Formulations
The specific ATG formulation, such as Thymoglobulin or ATGAM, may influence the dosing regimen, with Thymoglobulin often administered at a dose of 1.5 mg/kg/day for 3 days [ 1 ].
Efficacy of ATG
The efficacy of ATG in treating steroid-refractory aGVHD has been reported, with an overall response rate (ORR) of 55% for Thymoglobulin administered at a median dose of 3 mg/kg/day [ 1 ].
Key Points to Consider
- ATG is not a standard practice in ASCT, but can be used in certain cases, such as steroid-refractory aGVHD.
- The dosing regimen of ATG typically involves administering a dose of 1.5 to 2.5 mg/kg/day for 2-4 days.
- The specific ATG formulation may influence the dosing regimen.
- The efficacy of ATG in treating steroid-refractory aGVHD has been reported, with an ORR of 55% for Thymoglobulin. Some key points to consider when using ATG in ASCT include:
- The potential for infections, such as bacterial, viral, and fungal infections, which occurred in 37%, 10%, and 18% of patients, respectively [ 1 ].
- The potential for hepatic dysfunction, which occurred in 25% of patients [ 1 ].
- The potential for long-term survival to be low, even in responders [ 1 ].
From the FDA Drug Label
ATG-R 2 mg/kg IV administered once per day for 3 consecutive days pre-implantation (3 total doses) Administration was planned for Days -5, -4, and -3 pre-implantation, followed by 2 days of rest prior to implantation.
The use of Anti-Thymocyte Globulin (ATG) in Autologous Stem Cell Transplantation (ASCT) is not directly supported by the provided drug label, as the label discusses the use of ATG-R in the context of RETHYMIC implantation for the treatment of congenital athymia.
- Key points:
- The label does mention the administration of ATG-R at a dose of 2 mg/kg IV for 3 consecutive days pre-implantation.
- The administration schedule is planned for Days -5, -4, and -3 pre-implantation. However, this information is not directly relevant to the use of ATG in ASCT. 2
From the Research
Use of Anti-Thymocyte Globulin (ATG) in Autologous Stem Cell Transplantation (ASCT)
- The provided studies do not directly address the use of ATG in ASCT, as they focus on allogeneic hematopoietic stem cell transplantation (HSCT) 3, 4, 5, 6, 7.
- However, the studies suggest that ATG can be effective in preventing graft-versus-host disease (GVHD) and improving survival outcomes in allogeneic HSCT 3, 4, 5, 6.
- The optimal dosing of ATG is crucial, as overexposure can lead to increased non-relapse mortality, disease recurrence, and delayed immune reconstitution 5, 6, 7.
- Targeted dosing strategies based on ATG concentration monitoring or lymphocyte counts may improve outcomes by reducing the risk of overexposure 5, 6.
- Further research is needed to determine the optimal dosing strategy for ATG in ASCT, as the current evidence is limited to allogeneic HSCT.
Key Findings
- Low-dose ATG (2.5 mg/kg) may prevent moderate to severe acute GVHD in mismatched unrelated HSCT 3.
- A dose of 30 mg/kg ATG-F may lead to better outcomes in patients undergoing unrelated donor allogeneic HSCT compared to 60 mg/kg 4.
- Optimum ATG exposure after transplantation is associated with improved overall survival and event-free survival 5.
- Targeted dosing of ATG based on concentration monitoring or lymphocyte counts may reduce CMV/EBV reactivation and improve survival outcomes 6.
- Standard weight-based dosing of ATG may result in overexposure and poorer outcomes in certain patients 7.