Population Pharmacokinetic and Pharmacokinetic/Pharmacodynamic Target Attainment Analyses for Dalbavancin in Pediatric Patients

Abstract

Background: Dalbavancin, approved for the treatment of pediatric and adult patients with acute bacterial skin and skin structure infections, has a terminal half-life of >14 days allowing administration as a single-dose regimen. Methods: We developed a population pharmacokinetic (PK) model using 1124 dalbavancin concentrations from 211 pediatric patients, with allometric scaling of clearance and volume parameter exponents fixed at 0.75 and 1, respectively. Serum albumin was included as a covariate on all PK parameters; creatinine clearance or estimated glomerular filtration rate was a covariate on clearance. The final model, qualified by visual predictive checks and bootstrapping, was used to simulate 1000 PK profiles for a range of pediatric age groups. PK/pharmacodynamic target attainment (PTA) was calculated for targets associated with stasis, 1-log kill, and 2-log kill of Staphylococcus aureus (neutropenic murine thigh infection model). Results: Dalbavancin PK was well characterized by a three-compartment model. No additional significant covariates were identified. Simulations showed that single-dose (30-minute intravenous infusion) regimens of 22.5 mg/kg (patients <6 years) and 18 mg/kg (patients 6 years to <18 years) resulted in PTA ≥94% for minimal inhibitory concentrations ≤2 mg/L and ≤0.5 mg/L for the stasis and 2-log kill targets, respectively. PTA for pediatric patients was similar to adults with exposures within the range for adults administered 1500 mg dalbavancin. Conclusion: Dalbavancin PK in pediatric patients was well characterized by a three-compartment model. Simulations with the final model demonstrated adequate PTA across the entire age range for the approved pediatric dalbavancin doses.