Pharmacokinetic‐Pharmacodynamic Modeling of Dalbavancin, a Novel Glycopeptide Antibiotic

Dalbavancin is a novel glycopeptide with a 2-dose, once-weekly dosing regimen that is being developed for the treatment of complicated skin and skin structure infections caused by gram-positive bacteria. Monte Carlo simulations were performed for dalbavancin using population pharmacokinetic data and minimum inhibitory concentrations (MICs) for clinical trial isolates. The time-dependent target was the maintenance of free drug concentrations above the MICfor 14 days (t > MIC). The concentration-dependent target was an area under the concentration-time curve (AUC)/MIC ratio of approximately 1000 for Staphylococcus aureus and 100 for Streptococcus sp. These targets were used to estimate susceptibility breakpoints for dalbavancin. For S aureus, the estimated susceptibility breakpoint was ≤0.5 μg/mL using AUC 14 days /MIC and ≤1 μg/mL using t > MIC. For Streptococcus sp, the estimated susceptibility breakpoint was at least 2 μg/mL. Because dalbavancin MIC 90 s for these species are well below these values, the analysis supports the use of once-weekly dosing regimens of dalbavancin in the treatment of complicated skin and skin structure infections.