Comparison of Different Dose of Anti-T Lymphocyte Globulin (ATLG) in Haploidentical HSCT for GVHD Prophylaxis

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the only therapeutic option for many hematological malignancies. Haploidentical related donor transplantation is now considered an important allo-HSCT. GVHD prevention has a crucial role in post-transplant outcomes by potentially interfering with the graft-versus-leukemia (GVL) effect and immune reconstitution. In vivo T cell depletion (TCD) modalities, including anti-T lymphocyte globulin (ATLG)-based protocols have been widely used worldwide for GVHD prophylaxis.

Several European studies have shown that a dose of 30mg/kg of ATLG can effectively prevent GVHD with acceptable safety. But, the most commonly reported dose among Chinese population is 20mg/kg. Additionally, the main type of allo-HSCT in China is haploidentical transplantation. The application experience of ATLG in Europe mainly focuses on sibling and unrelated donor transplants. There is still a lack of sufficient exploration on the optimal dose of ATLG in GVHD prevention in haploidentical transplantation.

In this prospective multiple-center randomized trial, we aim to compare the effects of different doses of ATLG on GVHD prevention, risk of viral infection, and patient survival after haploidentical transplantation.

Inclusion criteria

• 1，Age ≥ 16 and ≤ 65 years 2, Patients undergoing Haplo-identical hematopoietic stem cell transplantation 3, AML and ALL in complete cytologic response or MDS requiring allogeneic stem cell transplantation 4, ECOG performance status ≤ 2

Exclusion criteria

• 1，Pregnant or lactating females 2，Patients who have previously undergone allogeneic hematopoietic stem cell transplantation or organ transplantation 3, Patients with major organ abnormal including renal, liver, lung , heart and/or CNS diseases, where these diseases or others cannot be controlled by treatment and may affect the completion of this study 4, Uncontrolled infection 5, Seropositivity for HIV or HTLV-1 or active hepatitis B or C 6, Patients with any other complications that may affect this study or with a history of malignant diseases.