(106) Evaluation of Post-Transplantation Cyclophosphamide, Tacrolimus, and Mycophenolate for Graft vs. Host Disease Prophylaxis in Patients Undergoing Allogenic Stem Cell Transplant

Poster Abstract:

Background: Hematopoietic stem cell transplantation is a strategy used to treat many malignant and non-malignant hematologic diseases. There are two types of stem cell transplants: autologous transplant recipients serve as their own donor, while allogenic transplant recipients receive cells from a non-self donor. Both types of transplants have a myriad of risks, but patients who receive an allogenic stem cell are specifically at risk for graft vs host disease (GVHD). This occurs when the donor T-cells attack the host cells, leading to tissue damage. Various studies estimate that up to 50% of patients who have undergone an allogenic stem cell transplant will experience some degree of experience GVHD. Historically, tacrolimus and methotrexate have been used to prevent GVHD. However, more transplant centers are starting to favor a regimen containing cyclophosphamide, tacrolimus, and mycophenolate. This is supported by a recent phase III study, where 34.9% of patients who received a cyclophosphamide-based regimen experienced grade III-IV GVHD, while 52.7% of patients who received the historical methotrexate-based regimen experienced grade III-IV GVHD. These results are promising, but more information regarding this regimen is necessary to move this regimen into the standard of care. This study will help internally validate the findings in the mentioned phase III study, address additional safety endpoints, including infection risk, and provide more information regarding this regimen use in the haploidentical transplant setting.

Objective: The primary outcome of this study is to compare the 1-year GVHD free survival between patients receiving post-transplantation cyclophosphamide, tacrolimus, and mycophenolate vs those receiving tacrolimus and methotrexate.

Methods: This single-health system, retrospective, observational study will be conducted at the University of Cincinnati Medical Center. Participants to be included must be at least 18 years who have undergone an allogenic bone marrow transplant without active GVHD at the time of transplant, and have received either cyclophosphamide, tacrolimus, and mycophenolate or tacrolimus and methotrexate as their GVHD prevention regimen. Exclusion criteria include active pregnancy and incarceration.

Results: Results pending.

Discussion/

Conclusions: The purpose of this study is to compare the 1-year GVHD free survival between patients receiving post-transplantation cyclophosphamide, tacrolimus, and mycophenolate vs those receiving tacrolimus and methotrexate. Results to be presented at the 2024 Hematology/Oncology Annual Conference.

References (must also be included in final poster): 1. Bolaños-Meade, Javier, et al. NEJM, vol. 388, no. 25, 22 June 2023, pp. 2338–2348.
2. Justiz Vaillant AA, Mohammadi O. Graft Versus Host Disease. PubMed. Published 2020.