Optimized cyclosporine starting dose may reduce risk of acute GvHD after allogeneic hematopoietic cell transplantation: a single-center cohort study.

Cyclosporine A (CsA) is commonly used for Graft versus Host Disease (GvHD) prophylaxis at a recommended starting dose of 3 mg/kg/d: Evidence for the effect of different CsA starting doses on GvHD risk is limited. We therefore estimated the association of 5 mg/kg/d (CsA5) and 3 mg/kg/d (CsA3) CsA starting doses with GvHD risk in two consecutive cohorts of allogeneic hematopoietic cell transplantation (allo-HCT) patients, exploring potential risk factors for incident acute GvHD, with a focus on CsA starting dose. We analyzed 519 patients within CsA5 (n = 153) and CsA3 (n = 366). The cumulative incidence function of acute GvHD grade ≥2 was higher in the CsA3 compared to the CsA5 group (41% vs. 33%, respectively; p = 0.043), without impacting chronic GvHD. In multivariable analysis, a CsA starting dose of 3 mg/kg/d, no ATG use, unrelated donor and high to very high disease risk index were significantly associated with acute GvHD grade ≥2. A higher CsA starting dose of 5 mg/kg/d was independently associated with lower acute GvHD risk, and higher CsA levels in the early period after allo-HCT were reached.