An optimised dosing regimen versus a standard dosing regimen of vancomycin for the treatment of late onset sepsis due to Gram-positive microorganisms in neonates and infants aged less than 90 days (NeoVanc): study protocol for a randomised controlled trial

Effectiveness of a low trough serum concentration of vancomycin on acute kidney injury in infants and toddlers in the paediatric intensive care unit

OBJECTIVE

This study aimed to assess the effectiveness of a low trough serum concentration of vancomycin on acute kidney injury in infants and toddlers in the paediatric intensive care unit (PICU).

METHODS

A retrospective cohort study was performed of 126 infants and toddlers (aged between 29 days and 3 years) from the PICU of a tertiary care hospital who were administered intravenous vancomycin between January 2019 and December 2022. Information about their demographic factors, duration of PICU stay, time of administration and trough levels of vancomycin were retrieved. Descriptive statistics were used for demographic factors and multivariable logistic regression analyses were conducted to assess the determining factors.

RESULTS

Based on the trough concentration of vancomycin, the participants were divided into three groups as follows: 4-5 mg/L, 5-15 mg/L and >15 mg/L. The serum vancomycin concentration was significantly related to body weight, albumin, cystatin C, urea nitrogen in serum, serum creatinine and creatinine clearance (p<0.05) in these patients. Multivariate analysis showed that body weight, albumin, cystatin C, urea nitrogen in serum and creatinine clearance were independent contributors to the trough vancomycin concentration. There was no difference in the effectiveness of different trough concentrations on patients (p=0.241). The cumulative incidence of acute kidney injury was highest in the group with a trough concentration of vancomycin >15 mg/L (p<0.01).

CONCLUSIONS

Patients with a vancomycin trough concentration of 4-5 mg/L in the PICU had a high cure rate (79.4%) and a low incidence of acute kidney injury (HR 18.3, 95% CI 5.135 to 87.621; p<0.001). Therefore, the serum trough concentration should be considered but it should also be combined with the treatment effect to achieve individualised administration for the clinical application of vancomycin.

Implementation of a Vancomycin Dose-Optimization Protocol in Neonates: Impact on Vancomycin Exposure, Biological Parameters, and Clinical Outcomes

Vancomycin dosing used in neonates results frequently in insufficient concentrations. A vancomycin dose-optimization protocol consisting of an individualization of loading and maintenance doses (administered during continuous infusion) through a previously validated pharmacokinetic model was implemented in our center. This monocenter retrospective study aimed to compare vancomycin average concentration (Cavg) in the therapeutic range (15 to 25 mg/L) and biological and clinical parameters before and after implementation of this protocol. A total of 60 and 59 courses of vancomycin treatment in 45 and 49 patients were analyzed in groups before and after implementation, respectively. Initial vancomycin Cavg were more frequently in the therapeutic range in the group after implementation (74.6% versus 28.3%, P < 0.001), with 1.6-fold higher Cavg (20.3 [17.0-22.2] mg/L versus 12.9 [11.3-17.0] mg/L, P < 0.001). Considering all Cavg during longitudinal therapeutic drug monitoring (TDM), the frequency of therapeutic Cavg was higher in the group after implementation (74.8% [n = 103] versus 31% [n = 116], P < 0.001). The dose optimization protocol was also associated with a reduced time to obtain a negative blood culture (P < 0.001) and fewer antibiotic switches (P = 0.025), without increasing the frequency of nephrotoxicity. Clinical outcomes also appeared to be improved, with less periventricular leukomalacia (P = 0.021), trended toward less respiratory instability (P = 0.15) and a shorter duration of vasoactive drug use (P = 0.18) for neonates receiving personalized doses of vancomycin. This personalized vancomycin dose protocol improves vancomycin exposure in neonates, with good safety, and suggests an improvement in biological and clinical outcomes.

Analysis of Paediatric Clinical Trial Characteristics and Activity Over 23 Years-Impact of the European Paediatric Regulation on a Single French Clinical Research Center

As unlicensed or off-label drugs are frequently prescribed in children, the European Pediatric Regulation came into force in 2007 to improve the safe use of medicinal products in the pediatric population. This present report analyzes the pediatric research trials over 23 years in a clinical research center dedicated to children and the impact of regulation. The database of trial characteristics from 1998 to 2020 was analyzed. We also searched for differences between two periods (1998-2006 and 2007-2020) and between institutional and industrial sponsors during the whole period (1998-2020). A total of 379 pediatric trials were initiated at our center, corresponding to inclusion of 7955 subjects and 19448 on-site patient visits. The trials were predominantly drug evaluation trials (n = 278, 73%), sponsored by industries (n = 216, 57%) or government/non-profit institutions (n = 163, 43%). All age groups and most subspecialties were concerned. We noted an important and regular increase in the number of trials conducted over the years, with an increased number of multinational, industrially sponsored trials. Based on the data presented, areas of improvement are discussed: (1) following ethical and regulatory approval depending on the sponsor, the mean time needed for administrative and financial agreement, validation of trial procedures allowing trial initiation at the level of the center was 6.3 and 6.5 months (periods 1 and 2, respectively) and should be reduced, (2) availability of expert research teams remain insufficient, time dedicated to research attributed to physicians should be organized and recognition of research nurses is required. The positive impact of the European Pediatric Regulation highlights the need to increase the availability of trained research teams, organized within identified multicenter international pediatric research networks.

Optimised versus standard dosing of vancomycin in infants with Gram-positive sepsis (NeoVanc): a multicentre, randomised, open-label, phase 2b, non-inferiority trial

BACKGROUND

Vancomycin is the most widely used antibiotic for neonatal Gram-positive sepsis, but clinical outcome data of dosing strategies are scarce. The NeoVanc programme comprised extensive preclinical studies to inform a randomised controlled trial to assess optimised vancomycin dosing. We compared the efficacy of an optimised regimen to a standard regimen in infants with late onset sepsis that was known or suspected to be caused by Gram-positive microorganisms.

METHODS

NeoVanc was an open-label, multicentre, phase 2b, parallel-group, randomised, non-inferiority trial comparing the efficacy and toxicity of an optimised regimen of vancomycin to a standard regimen in infants aged 90 days or younger. Infants with at least three clinical or laboratory sepsis criteria or confirmed Gram-positive sepsis with at least one clinical or laboratory criterion were enrolled from 22 neonatal intensive care units in Greece, Italy, Estonia, Spain, and the UK. Infants were randomly assigned (1:1) to either the optimised regimen (25 mg/kg loading dose, followed by 15 mg/kg every 12 h or 8 h dependent on postmenstrual age, for 5 ± 1 days) or the standard regimen (no loading dose; 15 mg/kg every 24 h, 12 h, or 8 h dependent on postmenstrual age for 10 ± 2 days). Vancomycin was administered intravenously via 60 min infusion. Group allocation was not masked to local investigators or parents. The primary endpoint was success at the test of cure visit (10 ± 1 days after the end of actual vancomycin therapy) in the per-protocol population, where success was defined as the participant being alive at the test of cure visit, having a successful outcome at the end of actual vancomycin therapy, and not having a clinically or microbiologically significant relapse or new infection requiring antistaphylococcal antibiotics for more than 24 h within 10 days of the end of actual vancomycin therapy. The non-inferiority margin was -10%. Safety was assessed in the intention-to-treat population. This trial is registered at ClinicalTrials.gov (NCT02790996).

FINDINGS

Between March 3, 2017, and July 29, 2019, 242 infants were randomly assigned to the standard regimen group (n=122) or the optimised regimen group (n=120). Primary outcome data in the per-protocol population were available for 90 infants in the optimised group and 92 in the standard group. 64 (71%) of 90 infants in the optimised group and 73 (79%) of 92 in the standard group had success at test of cure visit; non-inferiority was not confirmed (adjusted risk difference -7% [95% CI -15 to 2]). Incomplete resolution of clinical or laboratory signs after 5 ± 1 days of vancomycin therapy was the main factor contributing to clinical failure in the optimised group. Abnormal hearing test results were recorded in 25 (30%) of 84 infants in the optimised group and 12 (15%) of 79 in the standard group (adjusted risk ratio 1·96 [95% CI 1·07 to 3·59], p=0·030). There were six vancomycin-related adverse events in the optimised group (one serious adverse event) and four in the standard group (two serious adverse events). 11 infants in the intention-to-treat population died (six [6%] of 102 infants in the optimised group and five [5%] of 98 in the standard group).

INTERPRETATION

In the largest neonatal vancomycin efficacy trial yet conducted, no clear clinical impact of a shorter duration of treatment with a loading dose was demonstrated. The use of the optimised regimen cannot be recommended because a potential hearing safety signal was identified; long-term follow-up is being done. These results emphasise the importance of robust clinical safety assessments of novel antibiotic dosing regimens in infants.

FUNDING

EU Seventh Framework Programme for research, technological development and demonstration.

Population Pharmacokinetic Models of Vancomycin in Paediatric Patients: A Systematic Review

BACKGROUND

Vancomycin is commonly used to treat gram-positive bacterial infections in the paediatric population, but dosing can be challenging. Population pharmacokinetic (popPK) modelling can improve individualization of dosing regimens. The primary objective of this study was to describe popPK models of vancomycin and factors that influence pharmacokinetic (PK) variability in paediatric patients.

METHODS

Systematic searches were conducted in the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, International Pharmaceutical Abstracts and the grey literature without language or publication status restrictions from inception to 17 August 2020. Observational studies that described the development of popPK models of vancomycin in paediatric patients (< 18 years of age) were included. Risk of bias was assessed using the National Heart, Lung and Blood Institute Study Quality Assessment Tool for Case Series Studies.

RESULTS

Sixty-four observational studies (1 randomized controlled trial, 13 prospective studies and 50 retrospective studies of 9019 patients with at least 25,769 serum vancomycin concentrations) were included. The mean age was 2.5 years (range 1 day-18 years), serum creatinine was 47.1 ± 33.6 µmol/L, and estimated creatinine clearance was 97.4 ± 76 mL/min/1.73m². Most studies found that vancomycin PK was best described by a one-compartment model (71.9%). There was a wide range of clearance and volume of distribution (V_d) values (range 0.014-0.27 L/kg/h and 0.43-1.46 L/kg, respectively) with interindividual variability as high as 49.7% for clearance and 136% for V_d, proportional residual variability up to 37.5% and additive residual variability up to 17.5 mg/L. The most significant covariates for clearance were weight, age, and serum creatinine or creatinine clearance, and weight for V_d. Variable dosing recommendations were suggested.

CONCLUSION

Numerous popPK models of vancomycin were derived, however external validation of suggested dosing regimens and analyses in subgroup paediatric populations such as dialysis patients are still needed before a popPK model with best predictive performance can be applied for dosing recommendations. Significant intraindividual and interindividual PK variability was present, which demonstrated the need for ongoing therapeutic drug monitoring and derivation of PK models for vancomycin for certain subgroup populations, such as dialysis patients.

Challenges of Vancomycin Dosing and Therapeutic Monitoring in Neonates

Late-onset sepsis in neonates can lead to significant morbidity and mortality, especially in preterm infants. Vancomycin is commonly prescribed for the treatment of Gram-positive organisms, particularly methicillin-resistant Staphylococcus aureus (MRSA), coagulase-negative staphylococci, and ampicillin-resistant Enterococcus species in adult and pediatric patients. Currently, there is no consensus on optimal dosing and monitoring of vancomycin in neonates. Different vancomycin dosing regimens exist for neonates, but with many of these regimens, obtaining therapeutic trough concentrations can be difficult. In 2011, the Infectious Diseases Society of America recommended vancomycin trough concentrations of 15 to 20 mg/L or an AUC/MIC ratio of ≥400 for severe invasive diseases (e.g., MRSA) in adult and pediatric patients. Owing to recent reports of increased risk of nephrotoxicity associated with vancomycin trough concentrations of 15 to 20 mg/L and AUC/MIC of ≥400, a revised consensus guideline, recently published in 2020, no longer recommends monitoring vancomycin trough concentrations in adult patients. The guideline recommends an AUC/MIC of 400 to 600, which has been found to achieve clinical efficacy while reducing nephrotoxicity. However, these recommendations were derived solely from adult literature, as there are limited clinical outcomes data in pediatric and neonatal patients. Furthermore, owing to the variation of vancomycin pharmacokinetic parameters among the neonatal population, these recommendations for achieving vancomycin AUC/MIC of 400 to 600 in neonates require further investigation. This review will discuss the challenges of achieving optimal vancomycin dosing and monitoring in neonatal patients.