Antifungal Efficacy, Safety, and Single-Dose Pharmacokinetics of LY303366, a Novel Echinocandin B, in Experimental Pulmonary Aspergillosis in Persistently Neutropenic Rabbits

ABSTRACT LY303366 is a novel semisynthetic derivative of echinocandin B and a potent inhibitor of fungal (1,3)-β-d-glucan synthase. The antifungal efficacy and safety of LY303366 were investigated in treatment and prophylaxis of primary pulmonary aspergillosis due toAspergillus fumigatus in persistently neutropenic rabbits. Treatment study groups were either not treated (controls) or treated with amphotericin B (AmB) at 1 mg/kg of body weight per day or with LY303366 at 1, 5, 10, and 20 mg/kg/day. In rabbits treated with LY303366, there was a significant improvement in survival and a reduction in organism-mediated pulmonary injury measured by the number of infarcts, total lung weight, and ultrafast computerized tomography scan pulmonary lesion score. Rabbits receiving prophylactic LY303366 also demonstrated significant improvement in survival and reduction in organism-mediated pulmonary injury. AmB and LY303366 had comparable therapeutic efficacies by all parameters with the exception of reduction in tissue burden ofA. fumigatus, where AmB was superior to LY303366. LY303366 demonstrated a dose-dependent effect on hyphal injury with progressive truncation, swelling, and vacuolization. LY303366 administered in single doses of 1, 5, 10, and 20 mg/kg demonstrated dose-proportional increases in the maximum concentration of drug in plasma and the area under the concentration-time curve from 0 to 72 h with no changes in plasma drug clearance. The 1-mg/kg dosage maintained plasma drug levels above the MIC for 18 h, and dosages of ≥5 mg/kg maintained plasma drug levels above the MIC for the entire 24-h dosing interval. There was no significant elevation of the concentrations of hepatic transaminases or creatinine in serum in LY303366-treated rabbits. In summary, LY303366 improved survival and decreased pulmonary injury with no apparent toxicity in the treatment and prevention of invasive pulmonary aspergillosis in persistently neutropenic rabbits.

Download Full-text

Antifungal Efficacy of Caspofungin (MK-0991) in Experimental Pulmonary Aspergillosis in Persistently Neutropenic Rabbits: Pharmacokinetics, Drug Disposition, and Relationship to Galactomannan Antigenemia

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.46.1.12-23.2002 ◽

2002 ◽

Vol 46 (1) ◽

pp. 12-23 ◽

Cited By ~ 142

Author(s):

Ruta Petraitiene ◽

Vidmantas Petraitis ◽

Andreas H. Groll ◽

Tin Sein ◽

Robert L. Schaufele ◽

...

Keyword(s):

Drug Disposition ◽

Invasive Pulmonary Aspergillosis ◽

Tetrazolium Salt ◽

Pulmonary Injury ◽

Pulmonary Aspergillosis ◽

Fungal Burden ◽

Galactomannan Antigen ◽

Improvement In Survival ◽

Dose Dependent ◽

Antifungal Efficacy

ABSTRACT The antifungal efficacy, pharmacokinetics, and safety of caspofungin (CAS) were investigated in the treatment and prophylaxis of invasive pulmonary aspergillosis due to Aspergillus fumigatus in persistently neutropenic rabbits. Antifungal therapy consisted of 1, 3, or 6 mg of CAS/kg of body weight/day (CAS1, CAS3, and CAS6, respectively) or 1 mg of deoxycholate amphotericin B (AMB)/kg/day intravenously for 12 days starting 24 h after endotracheal inoculation. Prophylaxis (CAS1) was initiated 4 days before endotracheal inoculation. Rabbits treated with CAS had significant improvement in survival and reduction in organism-mediated pulmonary injury (OMPI) measured by pulmonary infarct score and total lung weight (P < 0.01). However, animals treated with CAS demonstrated a paradoxical trend toward increased residual fungal burden (log CFU per gram) and increased serum galactomannan antigen index (GMI) despite improved survival. Rabbits receiving prophylactic CAS1 also showed significant improvement in survival and reduction in OMPI (P < 0.01), but there was no effect on residual fungal burden. In vitro tetrazolium salt hyphal damage assays and histologic studies demonstrated that CAS had concentration- and dose-dependent effects on hyphal structural integrity. In parallel with a decline in GMI, AMB significantly reduced the pulmonary tissue burden of A. fumigatus (P ≤ 0.01). The CAS1, CAS3, and CAS6 dose regimens demonstrated dose-proportional exposure and maintained drug levels in plasma above the MIC for the entire 24-h dosing interval at doses that were ≥3 mg/kg/day. As serial galactomannan antigen levels may be used for therapeutic monitoring, one should be aware that profoundly neutropenic patients receiving echinocandins for aspergillosis might have persistent galactomannan antigenemia despite clinical improvement. CAS improved survival, reduced pulmonary injury, and caused dose-dependent hyphal damage but with no reduction in residual fungal burden or galactomannan antigenemia in persistently neutropenic rabbits with invasive pulmonary aspergillosis.

Download Full-text

Antifungal Activity and Pharmacokinetics of Posaconazole (SCH 56592) in Treatment and Prevention of Experimental Invasive Pulmonary Aspergillosis: Correlation with Galactomannan Antigenemia

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.45.3.857-869.2001 ◽

2001 ◽

Vol 45 (3) ◽

pp. 857-869 ◽

Cited By ~ 128

Author(s):

Ruta Petraitiene ◽

Vidmantas Petraitis ◽

Andreas H. Groll ◽

Tin Sein ◽

Stephen Piscitelli ◽

...

Keyword(s):

Lung Tissue ◽

Invasive Pulmonary Aspergillosis ◽

Plasma Drug ◽

Dose Dependency ◽

Multiple Dosing ◽

Pulmonary Aspergillosis ◽

Treatment And Prevention ◽

Hepatic Transaminase ◽

Improvement In Survival ◽

Antifungal Efficacy

ABSTRACT The antifungal efficacy, safety, and pharmacokinetics of posaconazole (SCH 56592) (POC) were investigated in treatment and prophylaxis of primary pulmonary aspergillosis due to Aspergillus fumigatus in persistently neutropenic rabbits. Antifungal therapy consisted of POC at 2, 6, and 20 mg/kg of body weight per os; itraconazole (ITC) at 2, 6, and 20 mg/kg per os; or amphotericin B (AMB) at 1 mg/kg intravenously. Rabbits treated with POC showed a significant improvement in survival and significant reductions in pulmonary infarct scores, total lung weights, numbers of pulmonary CFU per gram, numbers of computerized-tomography-monitored pulmonary lesions, and levels of galactomannan antigenemia. AMB and POC had comparable therapeutic efficacies by all parameters. By comparison, animals treated with ITC had no significant changes in outcome variables in comparison to those of untreated controls (UC). Rabbits receiving prophylactic POC at all dosages showed a significant reduction in infarct scores, total lung weights, and organism clearance from lung tissue in comparison to results for UC (P < 0.01). There was dosage-dependent microbiological clearance of A. fumigatus from lung tissue in response to POC. Serum creatinine levels were greater (P < 0.01) in AMB-treated animals than in UC and POC- or ITC-treated rabbits. There was no elevation of serum hepatic transaminase levels in POC- or ITC-treated rabbits. The pharmacokinetics of POC and ITC in plasma demonstrated dose dependency after multiple dosing. The 2-, 6-, and 20-mg/kg dosages of POC maintained plasma drug levels above the MICs for the entire 24-h dosing interval. In summary, POC at ≥6 mg/kg/day per os generated sustained concentrations in plasma of ≥1 μg/ml that were as effective in the treatment and prevention of invasive pulmonary aspergillosis as AMB at 1 mg/kg/day and more effective than cyclodextrin ITC at ≥6 mg/kg/day per os in persistently neutropenic rabbits.

Download Full-text

Pharmacokinetics and Concentration-Dependent Efficacy of Isavuconazole for Treatment of Experimental Invasive Pulmonary Aspergillosis

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.02665-15 ◽

2016 ◽

Vol 60 (5) ◽

pp. 2718-2726 ◽

Cited By ~ 26

Author(s):

Vidmantas Petraitis ◽

Ruta Petraitiene ◽

Patriss W. Moradi ◽

Gittel E. Strauss ◽

Aspasia Katragkou ◽

...

Keyword(s):

Invasive Pulmonary Aspergillosis ◽

Prolonged Survival ◽

Pulmonary Injury ◽

Pulmonary Aspergillosis ◽

Lower Serum ◽

Time Curve ◽

Content Type ◽

Fungal Burden ◽

Dose Dependent ◽

Significant Concentration

ABSTRACTWe studied the pharmacokinetics and efficacy of the broad-spectrum triazole isavuconazole for the treatment of experimental invasive pulmonary aspergillosis (IPA) in persistently neutropenic rabbits. Treatment started 24 h after endotracheal administration ofAspergillus fumigatusinoculum; study subjects included rabbits receiving orally administered prodrug isavuconazonium sulfate (BAL8557) equivalent to active moiety isavuconazole (ISA; BAL4815) at 20 (ISA20), 40 (ISA40), and 60 (ISA60) mg/kg (of body weight)/day, with an initial loading dose of 90 mg/kg (ISA90), and untreated rabbits (UC). There were significant concentration-dependent reductions of residual fungal burden (log CFU/gram) and of organism-mediated pulmonary injury, lung weights, and pulmonary infarct scores in ISA40- and ISA60-treated rabbits in comparison to those of UC (P< 0.001). ISA20-treated (P< 0.05), ISA40-treated, and ISA60-treated (P< 0.001) rabbits demonstrated significantly prolonged survival in comparison to that of UC. ISA40- and ISA60-treated animals demonstrated a significant decline of serum (1→3)-β-d-glucan levels (P< 0.05) and galactomannan indices (GMIs) during therapy following day 4 in comparison to progressive GMIs of UC (P< 0.01). There also were significantly lower concentration-dependent GMIs in bronchoalveolar lavage (BAL) fluid from ISA40- and ISA60-treated rabbits (P< 0.001). There was a direct correlation between isavuconazole plasma area under the concentration-time curve from 0 to 24 h (AUC0–24) and residual fungal burdens in lung tissues, pulmonary infarct scores, and total lung weights. In summary, rabbits treated with isavuconazole at 40 and 60 mg/kg/day demonstrated significant dose-dependent reduction of residual fungal burden, decreased pulmonary injury, prolonged survival, lower GMIs in serum and BAL fluid, and lower serum (1→3)-β-d-glucan levels.

Download Full-text