A Randomized Phase III Trial of Low Dose Liposomal Amphotericin B (L-AmB) as Prophylaxis of Invasive Fungal Infections (IFI) in Neutropenic Patients (pts).

Background The prophylactic use of systemic antifungal agents reduces morbidity and mortality after allogeneic hemopoietic stem cell transplantation (HSCT). However, the efficacy of this approach in pts receiving intensive chemotherapy or autologous HSCT is yet unproven. This trial was designed to evaluate the efficacy of L-AmB prophylaxis in high-risk neutropenic pts.

Methods: 231 pts with hematological malignancies and expected neutropenia (N) of more than 10 days (d) following intensive chemotherapy or autologous HSCT were enrolled, 219 pts became neutropenic and were randomized to receive either 50 mg L-AmB i.v. every second d (arm A) or no systemic antifungal prophylaxis (arm B). Treatment with L-AmB started 1–3 d prior onset of N and was continued until neutrophil recovery, breakthrough IFI, intolerable toxicity or death. The level of significance was 0.05 (two-sided) for all statistical analyses. Calculations were performed using commercially (SPSSWIN 12.0) software, the calculations for GEE were performed using the software MAREG.

Results Pt. characteristics: Eligible pts 219; arm A: 110; arm B: 109. Reasons for exclusion were: Absence of N (8), infection prior N (3) and pts decision (1). Baseline characteristics were balanced for age (mean 53.8 years), underlying disease (119 AML, 27 ALL, 64 NHL, 9 other), duration of N (mean 14.8 D) and treatment modality (primary 149, secondary 42, transplant 28). Primary endpoint: The incidence of proven and probable IFI was 5 of 110 pts (4.6%) in arm A and 22 of 109 pts (20.2%) in arm B (p = 0.001, RR = 2.9, CI 1.3 – 6.5). Key secondary endpoints: Pneumonia of unknown origin occurred in 6 pts (5.5%) vs. 28 pts (25.7%) (p < 0.001), the incidence of possible, probable and proven IFI was 11 pts (10.2%) vs. 42 pts (39.6%) (p < 0.001), systemic antifungals were used in 24 pts (22%) vs. 64 pts (59%) (p < 0.001), and death occurred in 4 pts (3.7%) vs. 9 pts (8.2%) (p = 0.16) in arm A vs. arm B. Toxicity: No grade 3 or 4 toxicity was noted. Laboratory abnormalities, including creatinine and liver function tests, were not different between the treatment groups.

Conclusion: Intermittent application of low dose L-AmB is save. The significant lower incidence of IFI in pts treated with L-AmB prophylaxis supports its use in prolonged N.