Modifying Post-Transplant Cyclophosphamide Platform to Improve Safety in HLA-Matched Allogeneic HCT: A Reduced Dose
Filipe R Pinto1, María Queralt Salas2, María Suárez-Lledó2
1Hematopoietic Transplantation Unit, Hematology Department, Institute of Cancer and Blood Diseases (ICAMS), Hospital Clínic de Barcelona, Barcelona, Spain.
Post-transplant cyclophosphamide (PTCY, 50 mg/kg/day for 2 days) is effective for GVHD prophylaxis after HLA-matched allogeneic hematopoietic cell transplantation (allo-HCT) but is associated with early toxicities. In November 2021, we implemented a modified platform using reduced-dose PTCY (40 mg/kg; PTCY40) with tacrolimus, plus G-CSF from day +7 and letermovir for CMV-positive patients. Outcomes of 56 patients receiving PTCY40 were compared to 59 historical controls treated with PTCY50. Median follow-up was 15 months. PTCY40 was associated with faster neutrophil and platelet recovery (median 15 versus 19 and 15 versus 21 days, respectively), improved CD4⁺ reconstitution, and fewer bloodstream infections by day +30 (19.6% versus 49.2%, P = .001). Early cardiac events and ICU admissions were numerically lower in the PTCY40 group (day +100: 5.4% versus 10.2%, P = .358; day +180 ICU: 5.4% versus 10.2%, P = .411). The cumulative incidence of grade II-IV acute GVHD was comparable (21.4% versus 18.6%, P = .641), while moderate/severe chronic GVHD was higher but not significant (1-year: 9.5% versus 1.9%, P = .105). Non-relapse mortality was significantly lower with PTCY40 (0% versus 8.6%, P = .032), with similar overall survival (78.2% versus 81.1%, P = .941) and relapse incidence (25.1% versus 24.1%, P = .772). These findings support the safety of this modified GVHD prophylaxis approach.
Post-transplant cyclophosphamide (PTCY, 50 mg/kg/day for 2 days) is effective for GVHD prophylaxis after HLA-matched allogeneic hematopoietic cell transplantation (allo-HCT) but is associated with early toxicities. In November 2021, we implemented a modified platform using reduced-dose PTCY (40 mg/kg; PTCY40) with tacrolimus, plus G-CSF from day +7 and letermovir for CMV-positive patients. Outcomes of 56 patients receiving PTCY40 were compared to 59 historical controls treated with PTCY50. Median follow-up was 15 months. PTCY40 was associated with faster neutrophil and platelet recovery (median 15 versus 19 and 15 versus 21 days, respectively), improved CD4⁺ reconstitution, and fewer bloodstream infections by day +30 (19.6% versus 49.2%, P = .001). Early cardiac events and ICU admissions were numerically lower in the PTCY40 group (day +100: 5.4% versus 10.2%, P = .358; day +180 ICU: 5.4% versus 10.2%, P = .411). The cumulative incidence of grade II-IV acute GVHD was comparable (21.4% versus 18.6%, P = .641), while moderate/severe chronic GVHD was higher but not significant (1-year: 9.5% versus 1.9%, P = .105). Non-relapse mortality was significantly lower with PTCY40 (0% versus 8.6%, P = .032), with similar overall survival (78.2% versus 81.1%, P = .941) and relapse incidence (25.1% versus 24.1%, P = .772). These findings support the safety of this modified GVHD prophylaxis approach.
Related Concept Videos
Bone Marrow Sampling and Transplants
The transplant begins with high doses of chemotherapy and radiation treatment, which aim to destroy...
Tissue Transplantation
The Biology of Tissue Transplantation
The biology of tissue transplantation hinges on the Major Histocompatibility Complex (MHC) molecules. These molecules...
Cell-mediated Immune Responses


