Standard Versus Reduced-Doses of Post-Transplant Cyclophosphamide in HLA Matched (10/10) Peripheral Blood Stem Cell Transplantation.

OBJECTIVE

This retrospective, single-center study aims to compare the efficacy and safety of a reduced dose of post-transplantation cyclophosphamide (PTCy) (60 mg/kg total dose) versus the standard dose (100 mg/kg total dose), both combined with tacrolimus, in adult patients undergoing allogeneic hematopoietic stem cell transplantation from HLA-matched related or unrelated donors.

METHODS

We report clinical outcomes of 59 consecutive patients who received standard doses of PTCy and 48 with the new reduced dose.

RESULTS

Neutrophil and platelet recovery occurred later in the standard-dose group (p < 0.01). The incidence of febrile neutropenia was higher in the standard-dose group (p < 0.01). No significant differences were found in the incidence of acute cardiac events, early bacteremia, CMV reactivation within the first 100 days post-HSCT, or the development of hemorrhagic cystitis. There were no significant differences in the incidence of grade II-IV and III-IV acute GvHD, moderate-to-severe chronic GvHD, or in 20-month overall survival and progression-free survival (p > 0.05). Non-relapse mortality at 100 days and at 1 year was comparable between groups, as was 1-year GVHD-free/relapse-free and immunosuppression-free survival (p > 0.05).

CONCLUSIONS

Reduced doses of CyPT combined with a single immunosuppressive agent are emerging as a safe and effective alternative for adult patients undergoing allo-HSCT from HLA-matched donors. Our findings support that this approach preserves key clinical outcomes while potentially reducing acute hematological and infectious toxicity.