Study Compares PTCy/Tac/MMF, Tacrolimus Plus Methotrexate to Prevent GVHD After HSCT

Post-transplant cyclophosphamide with tacrolimus and mycophenolate (PTCy/Tac/MMF) and tacrolimus plus methotrexate (Tac-MTX) provided similar rates of graft-versus-host disease (GVHD) prevention after allogeneic hematopoietic stem cell transplant (HSCT) with myeloablative conditioning, according to results of a retrospective study presented at the Hematology/Oncology Pharmacy Association Annual Conference 2024.

Adult patients who underwent HSCT with a human leukocyte antigen (HLA)-matched related donor (MRD) or an HLA-matched unrelated donor (MUD) at a single center were included. The primary outcome was GVHD-free, relapse-free survival (GRFS) at 1 year. Seventy-seven patients received a regimen of Tac-MTX and 13 patients received PTCy/Tac/MMF.

At 1 year, the rate of GRFS was 6.5% (95% CI, 1-12) in the Tac-MTX group and 21.0% (95% CI, 0-44) in the PTCy/Tac/MMF group (P=.066). In the Tac-MTX group, the rate of acute GVHD at any grade was 68.8% and at grade 3-4 was 7.8%; the rate of any chronic GVHD was 54.5% and moderate to severe chronic GVHD was 45.5%. In the PTCy/Tac/MMF group, 30.8% of patients developed acute GVHD and no patients developed grade 3-4 acute GVHD; 38.5% developed chronic GVHD overall and 23.1% developed moderate to severe GVHD. Median days to neutrophil engraftment was 18.0 days in the Tac-MTX group and 17.5 days in the PTCy/Tac/MMF group. The rate of 1-year relapse was 13% in the Tac-MTX group and 15% in the PTCy/Tac/MMF group; 1-year overall survival was 70% and 68%, respectively.

In summary, “PTCy/Tac/MMF and Tac-MTX did not significantly differ in regard to 1-year GRFS among those who received an HSCT from an MRD or MUD following myeloablative conditioning,” the authors wrote. They noted that the study is limited by the small PTCy/Tac/MMF group and the short follow-up period.

Reference

Cash MC, Eberwein EM, Eubanks ER, Schrum DP, Burrows J, Lee HJ. Post-transplant cyclophosphamide, tacrolimus, and mycophenolate vs. tacrolimus and methotrexate as graft-versus-host disease prevention following allogeneic stem cell transplant with myeloablative conditioning. Poster. Presented at the Hematology/Oncology Pharmacy Association Annual Conference 2024; April 3-6, 2024; Tampa, Florida.