Safety and efficacy of low-dose amphotericin B lipid complex for empirical antifungal therapy of neutropenic fever in patients with hematologic malignancies

Lower respiratory tract respiratory virus infections increase the risk of invasive aspergillosis after a reduced-intensity allogeneic hematopoietic SCT

We have analyzed the incidence and risk factors for the occurrence of invasive aspergillosis (IA) among 219 consecutive recipients of an allogeneic hematopoietic SCT after a reduced-intensity conditioning regimen (Allo-RIC). Twenty-seven patients developed an IA at a median of 218 days (range 24–2051) post-Allo-RIC, for a 4-year incidence of 13% (95% confidence interval 4–24%). In multivariate analysis, risk factors for developing IA were steroid therapy for moderate-to-severe graft vs host disease (GVHD) (Hazard Ratio (HR) 2.9, P=0.03), occurrence of a lower respiratory tract infection (LRTI) by a respiratory virus (RV) (HR 4.3, P<0.01) and CMV disease (HR 2.8, P=0.03). Variables that decreased survival after Allo-RIC were advanced disease phase (HR 1.9, P=0.02), steroid therapy for moderate-to-severe GVHD (HR 2.2, P<0.01), not developing chronic GVHD (HR 4.3, P<0.01), occurrence of LRTI by an RV (HR 3.4, P<0.01) and CMV disease (HR 2, P=0.01), whereas occurrence of IA had no effect on survival (P=0.5). Our results show that IA is a common infectious complication after an Allo-RIC, which occurs late post-transplant and may not have a strong effect on survival. An important observation is the possible role of LRTI by conventional RVs as risk factors for IA.

Empirical antifungal therapy in patients with neutropenia and persistent or recurrent fever of unknown origin

Persistent or recurrent fever of unexplained origin (PFUO) in neutropenic patients receiving antibiotic therapy is commonly treated with empirical antifungal therapy (EAFT). EAFT was established as an adequate management of PFUO around 20 years ago with conventional amphotericin B deoxycholate (c-AmB), despite its high rate of infusional and systemic toxicities. In recent years, EAFT trials for PFUO have used less toxic agents, such as the lipid formulations of AmB, the new azoles, and the echinocandin, caspofungin. In clinical trials, the lipid formulations of AmB [especially liposomal AmB (L-AmB)] provided similar efficacy with lower toxicity but at a much higher cost. Although rarely used in clinical practice, fluconazole is equivalent to c-AmB, provided patients at high risk of Aspergillus infections are excluded. Intravenous itraconazole was shown to be equivalent to c-AmB, with a lower toxicity. Voriconazole did not meet non-inferiority criteria when compared with L-AmB. Caspofungin was shown to be non-inferior to L-AmB and more effective in treating baseline invasive fungal infections. To date, alternatives to AmB have shown less toxicity, but improved efficacy is less clear. This is probably because of the weakness of the indication and to the consequent difficulty in establishing objective and reproducible endpoints for comparisons. The new challenge for physicians in this field is probably presumptive antifungal therapy, an approach based on patient risk-group stratification for developing invasive candidiasis or aspergillosis and/or the use of new diagnostic techniques to identify patients at a very early stage of infection.

Low-dose amphotericin B lipid complex vs. conventional amphotericin B for empirical antifungal therapy of neutropenic fever in patients with hematologic malignancies--a randomized, controlled trial

BACKGROUND

Conventional amphotericin B (c-AmB) remains the empirical antifungal treatment of choice for neutropenic patients with persistent fever of unknown origin (FUO). Unfortunately, empirical treatment with c-AmB is hampered by its safety profile, with frequent infusion-related adverse events (IRAEs) and renal toxicity. Amphotericin B lipid complex (ABLC) has been investigated for this indication due to its low toxicity profile. The recommended dose of ABLC is 5 mg/kg/d, which is five to seven times higher than the recommended dose of c-AmB.

METHODS

This randomized, controlled trial includes 105 adult patients with hematologic malignancies and with FUO after receiving chemotherapy or autologous stem cell transplantation. Patients were randomly allocated to receive ABLC at 1 mg/kg/d or c-AmB at 0.6 mg/kg/d for empirical antifungal therapy.

RESULTS

The incidence of renal toxicity was significantly lower in the ABLC group, compared with c-AmB group: 8% vs. 32%, respectively (P = 0.003). The rates of IRAEs were similar in both groups (73% for ABLC vs. 77% for c-AmB). The overall response rate was 72% for ABLC compared with 48% for c-AmB (P = 0.018). This difference was mainly due to the significantly higher renal toxicity in the c-AmB group. The number of emergent fungal infections and overall mortality were similar in both groups.

CONCLUSIONS

This randomized trial suggests that ABLC at 1 mg/kg/d produces less nephrotoxicity than c-AmB, without differences in the incidence of IRAEs and with similar efficacy.