The effect of cyclosporine initiation time on the outcome of matched allogeneic stem-cell transplantation following fludarabine-based conditioning.

Cyclosporine (CSA) is the most commonly used medication for GVHD prophylaxis. The initiation time varies from day -4 to day 0. Initially, we gave CSA starting on day -1. However, since 2003 we have changed CSA initiation timing policy in most of our protocols to day -4, to achieve stable and controlled pretransplant CSA levels. Here, we assessed if initiation time impact the outcome of allogeneic stem-cell transplantation (allo-SCT). Data of 261 patients who underwent allo-SCT for hematological malignancies from a fully matched donor, treated with CSA as a single agent for GVHD prophylaxis were prospectively collected. Patients were divided according to CSA initiation time and analyzed for outcome. The acute GVHD severity, cGVHD extent, GVHD-associated mortality were significantly lower in the CSA -4 group. There was no difference in the rate and timing of acute or chronic GVHD. Overall survival did not differ between the groups. We conclude that the initiation of CSA at day -4 reduced the severity of aGVHD, extent of cGVHD, and GVHD-associated mortality without impact on overall survival.