Does antithymocyte globulin have a place in reduced-intensity conditioning for allogeneic hematopoietic stem cell transplantation?

A 63-year-old male patient without siblings is treated for acute myeloid leukemia with poor prognostic cytogenetics. Despite achieving a first complete remission, he relapsed within the first year of diagnosis. He then achieved a second complete remission. A search for an HLA-identical unrelated donor identified a 10/10 possible match. The patient has several comorbidities (hematopoietic stem cell comorbidity index = 3) and it is recommended that he undergo a reduced-intensity conditioning regimen for allogeneic peripheral blood stem cell transplantation. The patient is well-read on allogeneic stem cell transplantation and asks you the merits of antithymocyte globulin that you propose to include in the conditioning regimen.