Isavuconazonium or posaconazole for antifungal prophylaxis in patients with acute myeloid leukemia

Background Invasive fungal infection (IFI) prophylaxis is recommended in patients with acute myeloid leukemia (AML) during induction chemotherapy. Posaconazole (POSA) is the recommended agent of choice; however, this medication can be associated with QTc prolongation, hepatotoxicity, and drug-drug interactions. Furthermore, there is conflicting evidence for the role of isavuconazole (ISAV) in this setting as an alternative to POSA. Objective The primary objective of this study was to evaluate the use of ISAV prophylaxis for primary IFI prevention in patients with AML undergoing induction. Additionally, the study investigated the use of ISAV trough concentration monitoring and compared these results to the efficacy of POSA therapeutic drug monitoring (TDM). Other secondary objectives included assessing the rates of toxicities associated with either prophylactic agent. This study analyzed the impact these toxicities had on patient outcomes by examining the need to hold or discontinue therapy. The final endpoint considered the efficacy associated with multiple dosing strategies employed at the study institution. Specifically, this included the use of loading doses or foregoing these when initiating prophylaxis. Methods This was a retrospective, single-center, cohort study. Patients included in this study were adults with AML admitted to Duke University Hospital between June 30, 2016 and June 30, 2021, who received induction chemotherapy and primary IFI prophylaxis for at least 7 days. Exclusion criteria included patients who received concomitant antifungal agents and patients who received antifungal agents as secondary prophylaxis. Results 241 patients met inclusion criteria with 12 (4.98%) participants in the ISAV group and 229 (95.02%) participants in the POSA group. The IFI incidence in the POSA group was 14.5%, while the ISAV group did not have any occurrences of IFI. No significant difference was found in the rate of IFI occurrence between the two treatment groups (p = 0.3805). Furthermore, it was demonstrated that the use of a loading dose when initiating prophylaxis could impact rates of IFI for this patient population. Conclusion Due to no difference in incidence, patient specific factors such as concomitant medications and baseline QTc should influence the choice between prophylactic agent.