Comparative Pharmacodynamics of Echinocandins against Aspergillus fumigatus Using an In Vitro Pharmacokinetic/Pharmacodynamic Model That Correlates with Clinical Response to Caspofungin Therapy: Is There a Place for Dose Optimization?
- 1 April 2021
- journal article
- research article
- Published by American Society for Microbiology in Antimicrobial Agents and Chemotherapy
- Vol. 65 (4)
- https://doi.org/10.1128/AAC.01618-20
Abstract
Echinocandins have been used as primary therapy of invasive aspergillosis (IA), with suboptimal results at standard dosing. Here, we explored the efficacy of dose escalation in a validated in vitro pharmacokinetic/pharmacodynamic (PK/PD) model. Six echinocandin wild-type (WT) and three non-WT A. fumigatus isolates were tested in an in vitro PK/PD model simulating anidulafungin, caspofungin, and micafungin exposures with a free drug maximum concentration (fC(max)) of 0.01 to 16 mg/liter and a half-life (t(1/2)) of 8 to 22 h. The relationship between the area under the dosing interval time-free drug concentration curve (fAUC(0-24))/minimum effective concentration (MEC) and % aberrant mycelium formation was analyzed. PK/PD indices associated with 50 to 99.99% maximal activity (El(50) to El(99.99)) were correlated with the clinical outcome of a 50-mg/day standard dose of caspofungin. The probability of target attainment (PTA) was calculated for different dosing regimens of each echinocandin via Monte Carlo analysis. A sigmoidal PK/PD relationship was found for WT isolates with El(99) values of 766, 8.8, and 115 fAUC(0-24)/CLSI MEC for anidulafungin, caspofungin, and micafungin, respectively. No aberrant mycelia were observed for non-WT isolates, irrespective of their MEC and drug exposure. The El(99), El(99.9), and El(99.99) values corresponded to 2-, 3-, and 4-log 10 formation of aberrant mycelia and correlated with survival, favorable, and complete response rates to caspofungin primary therapy in patients with IA. A very low PTA (= 90% was found with 100 and 150 mg/day of caspofungin and 1,400 mg/day micafungin against WT isolates. For anidulafungin, the PTA for 1,500 mg/day was 10%. Among the three echinocandins, only caspofungin at 2 or 3 times the licensed dosing was associated with a high PTA. Caspofungin dose escalation might deserve clinical validation.This publication has 54 references indexed in Scilit:
- Echinocandins for the Treatment of Invasive Aspergillosis: from Laboratory to BedsideAntimicrobial Agents and Chemotherapy, 2019
- Diagnosis and management of Aspergillus diseases: executive summary of the 2017 ESCMID-ECMM-ERS guidelineClinical Microbiology & Infection, 2018
- Practice Guidelines for the Diagnosis and Management of Aspergillosis: 2016 Update by the Infectious Diseases Society of AmericaClinical Infectious Diseases, 2016
- Clinical evidence for caspofungin monotherapy in the first‐line and salvage therapy of invasive Aspergillus infectionsMycoses, 2016
- Micafungin for the treatment of invasive aspergillosisJournal of Infection, 2014
- Breakthrough invasive mould infections in patients treated with caspofunginJournal of Infection, 2012
- Breakthrough Aspergillus fumigatus and Candida albicans Double Infection during Caspofungin Treatment: Laboratory Characteristics and Implication for Susceptibility TestingAntimicrobial Agents and Chemotherapy, 2009
- Breakthrough invasive aspergillosis in allogeneic haematopoietic stem cell transplant recipients treated with caspofunginInternational Journal of Antimicrobial Agents, 2007
- Mould breakthrough in immunosuppressed adults receiving anidulafungin: A report of 2 casesJournal of Infection, 2007
- Pharmacokinetic and Pharmacodynamic Modeling of Anidulafungin (LY303366): Reappraisal of Its Efficacy in Neutropenic Animal Models of Opportunistic Mycoses Using Optimal Plasma SamplingAntimicrobial Agents and Chemotherapy, 2001