Compared with standard graft vs host disease (GVHD) prophylaxis of tacrolimus and methotrexate (Tac-MTX), post-transplantation cyclophosphamide (PTCy) in combination with sirolimus (PTCy-Siro) was associated with a shorter median time to immunosuppression withdrawal and a lower rate of chronic GVHD in patients who underwent matched-donor allogeneic hematopoietic cell transplant (allo-HCT), according to research published in Transplantation and Cellular Therapy.

Researchers conducted a single-center, nonrandomized study of patients who underwent matched related donor (MRD) or matched unrelated donor (MUD) allo-HCT and were receiving PTCy-Siro or Tac-MTX as GVHD prophylaxis between January 2018 to January 2021.

A total of 116 patients underwent MRD and MUD allo-HCT. Of those, 25% were receiving PTCy-Siro (n=29; median age, 48 years; range, 24-69) and 75% were receiving Tac-MTX (n=87; median age, 59.5 years; range, 20-73 years). The most common indication for allo-HCT was non-Hodgkin lymphoma (37.9%) for patients receiving PTCy-Siro and acute myeloid leukemia (31%) for those receiving Tac-MTX.

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The researchers found patients receiving PTCy-Siro had a significantly shorter median time to immunosuppression withdrawal compared with patients receiving Tac-MTX (138 vs 232 days; P <.001). They found no significant difference between the groups in the incidence of grade II to IV acute GVHD, grade III to IV acute GVHD, steroid refractory acute GVHD, or clinical infections.

At a median follow-up duration of 1.1 years (range, 0-1.8), the team noted patients receiving PTCy-Siro had a significantly lower likelihood of developing chronic GVHD compared with patients receiving Tac-MTX (2-year freedom from GVHD, 75% vs 20%; P =.005).

“The results of our study indicate that the combination of PTCy-Siro is feasible and is associated with lower rates of chronic GVHD, while also allowing for early withdrawal of immunosuppression in comparison to the standard Tac-MTX,” the researchers concluded in their report.

Limitations of the study included the single-center, retrospective design, relatively small number of patients in the PTCy-Siro group, nonrandomized comparison, possible

physician bias in the selection of PTCy-Siro or Tac -MTX as GVHD prophylaxis, and inclusion of various disease diagnoses and myeloablative and reduced intensity conditioning regimens.


Iqbal M, Nieto FAM, Brannick KM, et al. A calcineurin inhibitor free graft versus host disease prophylaxis for patients undergoing matched related and matched unrelated donor allogeneic hematopoietic cell transplant. Transplant Cell Ther. Published online February 7, 2023. doi:10.1016/j.jtct.2023.02.001