New age GVHD prophylaxis regimens: what works for what donor and why Available to Purchase

Allogeneic hematopoietic stem-cell transplantation is a curative modality for hematologic malignancies, bone marrow failure syndromes, hemoglobinopathies, and other nonmalignant disorders. Graft-versus-host disease (GVHD)—in its acute or chronic form—is an important transplant complication. The effective prevention of GVHD is crucial to the success of allotransplantation. Acute GVHD is mediated by the recognition of recipient antigens by donor T lymphocytes, with the subsequent activation and proliferation of T cells and establishment of an inflammatory cytokine cascade. Chronic GVHD is mediated by T-cell, B-cell, and macrophage activation with eventual inflammation and fibrosis. Standard approaches for GVHD prevention have been calcineurin-inhibitor (CNI) based, while newer approaches have focused on adding in-vivo T-cell modulation to a CNI backbone with antimetabolites such as posttransplant cyclophosphamide (PTCy), checkpoint blocking agents such as abatacept, or mammalian target of rapamycin (mTOR) inhibition with sirolimus. Still other approaches focus on blocking T-cell trafficking to target organs via integrin blockade (vedolizumab), cytokine blockade (JAK inhibitors), and B-cell blockade for chronic GVHD prevention. The use of PTCy and abatacept have improved allotransplantation safety and efficacy with human leukocyte antigen (HLA)-mismatched as well as HLA-matched donors, thus expanding the donor pool greatly for patients of all ancestries, and ushering in a new era in transplantation where donors are available for almost every patient.