Impact of cyclosporine A concentration on acute graft-vs-host disease incidence after haploidentical hematopoietic cell transplantation

Objectives: This retrospective study analyzed the impact of early cyclosporine A (CsA) initiation (day −3) on the risk of acute graft-vs-host disease (aGvHD) after haploidentical hematopoietic cell transplantation (Haplo-HCT) using post-transplant cyclophosphamide. Methods: Sixty-one consecutives patients who underwent Haplo-HCT were analyzed. Results: At day +180, the cumulative incidences of grade II-IV and grade III-IV aGvHD were 39% and 18%, respectively. Patients having a lowest CsA concentration (<301 ng/mL; the cutoff value used to segregate the patients between low and high CsA concentrations) in the first week after Haplo-HCT had a significantly higher risk of grade II-IV aGvHD (P = 0.02), severe grade III-IV aGvHD (P = 0.03), cGvHD (P = 0.02), and extensive cGvHD (P = 0.04). In multivariate analysis, a higher CsA concentration (≥301 ng/mL) during the first week following Haplo-HCT was the only parameter significantly associated with a reduced risk of grade II-IV and grade III-IV aGvHD (RR = 0.21; P = 0.049 and RR < 0.001; P < 0.0001, respectively). We find no correlation between CsA concentration and relapse, non-relapse mortality, progression-free survival, GvHD-free and progression-free survival, or overall survival. Conclusions: CsA could be initiated early before Haplo-HCT with achievement of high CsA concentration to reduce the risk of aGvHD without any detrimental effect on relapse.