Advancing Pediatric Antibacterial Drug Development: A Critical Need to Reinvent our Approach

Potential Antibiotics for the Treatment of Neonatal Sepsis Caused by Multidrug-Resistant Bacteria

Neonatal sepsis causes up to an estimated 680,000 deaths annually worldwide, predominantly in low- and middle-income countries (LMICs). A significant and growing proportion of bacteria causing neonatal sepsis are resistant to multiple antibiotics, including the World Health Organization-recommended empiric neonatal sepsis regimen of ampicillin/gentamicin. The Global Antibiotic Research and Development Partnership is aiming to develop alternative empiric antibiotic regimens that fulfil several criteria: (1) affordable in LMIC settings; (2) activity against neonatal bacterial pathogens, including extended-spectrum β-lactamase producers, gentamicin-resistant Gram-negative bacteria, and methicillin-resistant Staphylococcus aureus (MRSA); (3) a licence for neonatal use or extensive experience of use in neonates; and (4) minimal toxicities. In this review, we identify five antibiotics that fulfil these criteria: amikacin, tobramycin, fosfomycin, flomoxef, and cefepime. We describe the available characteristics of each in terms of mechanism of action, resistance mechanisms, clinical pharmacokinetics, pharmacodynamics, and toxicity profile. We also identify some knowledge gaps: (1) the neonatal pharmacokinetics of cefepime is reliant on relatively small and limited datasets, and the pharmacokinetics of flomoxef are also reliant on data from a limited demographic range and (2) for all reviewed agents, the pharmacodynamic index and target has not been definitively established for both bactericidal effect and emergence of resistance, with many assumed to have an identical index/target to similar class molecules. These five agents have the potential to be used in novel combination empiric regimens for neonatal sepsis. However, the data gaps need addressing by pharmacokinetic trials and pharmacodynamic characterisation.

Hospital-acquired Pneumonia and Ventilator-associated Pneumonia in Children: A Prospective Natural History and Case-Control Study

BACKGROUND

Clinical trials for antibiotics designed to treat hospital-acquired and ventilator-associated bacterial pneumonias (HABP/VABP) are hampered by making these diagnoses in a way that is acceptable to the United States Food and Drug Administration and consistent with standards of care. We examined laboratory and clinical features that might improve pediatric HABP/VABP trial efficiency by identifying risk factors predisposing children to HABP/VABP and describing the epidemiology of pediatric HABP/VABP.

METHODS

We prospectively reviewed the electronic medical records of patients <18 years of age admitted to intensive and intermediate care units (ICUs) if they received qualifying respiratory support or were started on antibiotics for a lower respiratory tract infection or undifferentiated sepsis. Subjects were followed until HABP/VABP was diagnosed or they were discharged from the ICU. Clinical, laboratory and imaging data were abstracted using structured chart review. We calculated HABP/VABP incidence and used a stepwise backward selection multivariable model to identify risk factors associated with development of HABP/VABP.

RESULTS

A total of 862 neonates, infants and children were evaluated for development of HABP/VABP; 10% (82/800) of those receiving respiratory support and 12% (103/862) overall developed HABP/VABP. Increasing age, shorter height/length, longer ICU length of stay, aspiration risk, blood product transfusion in the prior 7 days and frequent suctioning were associated with increased odds of HABP/VABP. The use of noninvasive ventilation and gastric acid suppression were both associated with decreased odds of HABP/VABP.

CONCLUSIONS

Food and Drug Administration-defined HABP/VABP occurred in 10%-12% of pediatric patients admitted to ICUs. Risk factors vary by age group.

Standardising neonatal and paediatric antibiotic clinical trial design and conduct: the PENTA-ID network view

Antimicrobial development for children remains challenging due to multiple barriers to conducting randomised clinical trials (CTs). There is currently considerable heterogeneity in the design and conduct of paediatric antibiotic studies, hampering comparison and meta-analytic approaches. The board of the European networks for paediatric research at the European Medicines Agency (EMA), in collaboration with the Paediatric European Network for Treatments of AIDS-Infectious Diseases network (www.penta-id.org), recently developed a Working Group on paediatric antibiotic CT design, involving academic, regulatory and industry representatives. The evidence base for any specific criteria for the design and conduct of efficacy and safety antibiotic trials for children is very limited and will evolve over time as further studies are conducted. The suggestions being put forward here are based on the adult EMA guidance, adapted for neonates and children. In particular, this document provides suggested guidance on the general principles of harmonisation between regulatory and strategic trials, including (1) standardised key inclusion/exclusion criteria and widely applicable outcome measures for specific clinical infectious syndromes (CIS) to be used in CTs on efficacy of antibiotic in children; (2) key components of safety that should be reported in paediatric antibiotic CTs; (3) standardised sample sizes for safety studies. Summarising views from a range of key stakeholders, specific criteria for the design and conduct of efficacy and safety antibiotic trials in specific CIS for children have been suggested. The recommended criteria are intended to be applicable to both regulatory and clinical investigator-led strategic trials and could be the basis for harmonisation in the design and conduct of CTs on antibiotics in children. The next step is further discussion internationally with investigators, paediatric CTs networks and regulators.