Effectiveness of posaconazole as primary prophylaxis in allogeneic hematopoietic stem cell transplantation.

We retrospectively analyzed the effectiveness of posaconazole (tablet and infusion formulations) and its correlation with blood concentration in preventing invasive fungal infections (IFIs) in 360 patients who underwent allogeneic hematopoietic stem cell transplant (allo-HSCT) between 2010 and 2023. A total of 61 patients received posaconazole, 102 received micafungin, and 197 received fluconazole for primary prophylaxis. By day 100 post-transplant, the cumulative incidence of IFIs was significantly lower with posaconazole (5.0%) compared with fluconazole (14.4%) or micafungin (16.9%). Multivariate analysis showed that the risk of IFIs was significantly higher with fluconazole/micafungin than with posaconazole (hazard ratio 4.04, 95% CI 1.17-13.94, P = 0.027). This difference was most notable among patients with lymphoid malignancies (P = 0.053) and those undergoing repeat transplantation (P = 0.024). There were no significant differences in overall survival, non-relapse mortality, or mortality from IFI. Mean blood levels of posaconazole dropped to 0.57 μg/mL two weeks after allo-HSCT, coinciding with the observation of most IFIs in the posaconazole group shortly after transplant. Posaconazole appears to be more effective than fluconazole or micafungin as primary prophylaxis against IFIs in allo-HSCT recipients.