Safety, dosing, and pharmaceutical quality for studies that evaluate medicinal products (including biological products) in neonates

Drug related adverse event assessment in neonates in clinical trials and clinical care

INTRODUCTION

Assessment of drug-related adverse events is essential to fully understand the benefit-risk balance of any drug exposure, weighing efficacy versus safety. This is needed for both drug labeling and clinical decision-making. Assessment is based on seriousness, severity and causality, be it more difficult to apply in neonates. Adverse event detection or prevention in the neonatal clinical setting is also more complicated because of polypharmacy, and off-label or unlicensed pharmacotherapy.

AREAS COVERED

Tools became available to assess severity and causality of adverse events in neonates recruited in clinical trials. The first version of the Neonatal Adverse Event severity score (NAESS) reduced the inter-observer variability. Causality tools like the Naranjo score were also tailored to neonates. These tools are also instrumental to support proactive pharmacovigilance in clinical care, while multidisciplinary care teams and computerized pharmacovigilance using advanced data analysis, like machine learning are emerging approaches to develop effective decision strategies.

EXPERT OPINION

All stakeholders involved in development of medicines or its clinical use should be aware of the limitations of the currently available assessment tools. Extension and optimization of these tools, advanced data analysis approaches, and capturing the variability in time-dependent physiology are warranted to improve pharmacovigilance in neonates.

Minimum effective dose of clemastine in a mouse model of preterm white matter injury

BACKGROUND

Preterm white matter injury (PWMI) is the most common cause of brain injury in premature neonates. PWMI involves a differentiation arrest of oligodendrocytes, the myelinating cells of the central nervous system. Clemastine was previously shown to induce oligodendrocyte differentiation and myelination in mouse models of PWMI at a dose of 10 mg/kg/day. The minimum effective dose (MED) of clemastine is unknown. Identification of the MED is essential for maximizing safety and efficacy in neonatal clinical trials. We hypothesized that the MED in neonatal mice is lower than 10 mg/kg/day.

METHODS

Mouse pups were exposed to normoxia or hypoxia (10% FiO2) from postnatal day 3 (P3) through P10. Vehicle or clemastine at one of four doses (0.5, 2, 7.5 or 10 mg/kg/day) was given to hypoxia-exposed pups. Myelination was assessed at age P14 and 10 weeks to determine the MED. Clemastine pharmacokinetics were evaluated at steady-state on day 8 of treatment.

RESULTS

Clemastine rescued hypoxia-induced hypomyelination with a MED of 7.5 mg/kg/day. Pharmacokinetic analysis of the MED revealed Cmax 44.0 ng/mL, t1/2 4.6 h, and AUC24 280.1 ng*hr/mL.

CONCLUSIONS

Based on these results, myelination-promoting exposures should be achievable with oral doses of clemastine in neonates with PWMI.

IMPACT

Preterm white matter injury (PWMI) is the most common cause of brain injury and cerebral palsy in premature neonates. Clemastine, an FDA-approved antihistamine, was recently identified to strongly promote myelination in a mouse model of PWMI and is a possible treatment. The minimum effective dose in neonatal rodents is unknown and is critical for guiding dose selection and balancing efficacy with toxicity in future clinical trials. We identified the minimum effective dose of clemastine and the associated pharmacokinetics in a murine chronic hypoxia model of PWMI, paving the way for a future clinical trial in human neonates.

Health Benefits of Antioxidant Bioactive Compounds in Ginger (Zingiber officinale) Leaves by Network Pharmacology Analysis Combined with Experimental Validation

Network pharmacology is an ideal tool to explore the effects of therapeutic components derived from plants on human metabolic diseases that are linked to inflammation. This study investigated the antioxidant effects of ginger leaves (GLs) and predicted targets for antioxidant activity. Quantitative and free radical scavenging analyses were performed to detect the main bioactive compounds of GLs and evaluate their antioxidant activities. Chemical diversity and network pharmacology approaches were used to predict key antioxidant components of GLs and their molecular targets. Nine major bioactive compounds of GLs were quantified using an internal standard method, and the antioxidant activity was evaluated using the DPPH and ABTS free radical scavenging methods. We first built the compound-gene-pathways and protein-protein interaction networks of GLs-related antioxidant targets and then conducted gene ontology and Kyoto Encyclopedia of Gene and Genome (KEGG) pathway enrichment analyses. Molecular docking results show that astragalin, a compound isolated from GLs, had the highest level of connectivity in the compound-target network and was involved in inflammation-related biosynthesis by directly impacting cytokine gene expression and PTGS2 inhibition markers. These findings not only suggest that the compounds isolated from GLs can be developed as potential antioxidants, but also demonstrate the applicability of network pharmacology to assess the potential of foods for disease treatment.

Positive end-expiratory pressure and surfactant administration mode influence function in ex-vivo premature sheep lungs

AIM

Respiratory distress syndrome often necessitates endotracheal surfactant administration in extremely preterm infants. Our study aimed to explore a multi-modal simulation tool for investigating treatment strategies in ex vivo sheep lungs during spontaneous breathing.

METHODS

An electromechanical lung simulator (xPULM) mimicking spontaneous breathing was coupled with a non-aerated premature sheep lung, replicating a premature respiratory system. Changes in tidal volume for different positive end-expiratory pressure (PEEP) levels prior to and after either bolus or nebulised surfactant administration were compared.

RESULTS

In two preterm sheep lungs, we observed a progressive decline in tidal volume with increasing PEEP levels prior to surfactant delivery from 0.30 ± 0.01 mL at zero PEEP to 0.04 ± 0.01 mL at 15 cmH2O PEEP. Our measurements showed that both bolus (p < 0.05) and nebulised (p < 0.05) surfactant administration resulted in a significant increase in tidal volume, with no significant difference (p = 0.71) between the two methods.

CONCLUSION

The experimental setup demonstrated the feasibility of xPULM for investigating the effectiveness of different PEEP levels and modes of surfactant administration with respect to tidal volume in premature sheep lungs. The lack of adequate lung water resorption in our model warrants further investigations.

Minimum Effective Dose of Clemastine in a Mouse Model of Preterm White Matter Injury

Background

Preterm white matter injury (PWMI) is the most common cause of brain injury in premature neonates. PWMI involves a differentiation arrest of oligodendrocytes, the myelinating cells of the central nervous system. Clemastine was previously shown to induce oligodendrocyte differentiation and myelination in mouse models of PWMI at a dose of 10 mg/kg/day. The minimum effective dose (MED) of clemastine is unknown. Identification if the MED is essential for maximizing safety and efficacy in neonatal clinical trials. We hypothesized that the MED in neonatal mice is lower than 10 mg/kg/day.

Methods

Mouse pups were exposed to normoxia or hypoxia (10% FiO 2 ) from postnatal day 3 (P3) through P10. Vehicle or clemastine fumarate at one of four doses (0.5, 2, 7.5 or 10 mg/kg/day) was given orally to hypoxia-exposed pups. At P14, myelination was assessed by immunohistochemistry and electron microscopy to determine the MED. Clemastine pharmacokinetics were evaluated at steady-state on day 8 of treatment.

Results

Clemastine rescued hypoxia-induced hypomyelination with a MED of 7.5 mg/kg/day. Pharmacokinetic analysis of the MED revealed C max 44.0 ng/mL, t 1/2 4.6 hours, and AUC 24 280.1 ng*hr/mL.

Conclusion

Based on these results, myelination-promoting exposures should be achievable with oral doses of clemastine in neonates with PWMI.

Key Points

Preterm white matter injury (PWMI) is the most common cause of brain injury and cerebral palsy in premature neonates.Clemastine, an FDA-approved antihistamine, was recently identified to strongly promote myelination in a mouse model of PWMI and is a possible treatment.The minimum effective dose in neonatal rodents is unknown and is critical for guiding dose selection and balancing efficacy with toxicity in future clinical trials.We identified the minimum effective dose of clemastine and the associated pharmacokinetics in a murine chronic hypoxia model of PWMI, paving the way for a future clinical trial in human neonates.

The neonatal adverse event severity scale: current status, a stakeholders' assessment, and future perspectives

To support informed decisions on drug registration and prescription, clinical trials need tools to assess the efficacy and safety signals related to a given therapeutic intervention. Standardized assessment facilitates reproducibility of results. Furthermore, it enables weighted comparison between different interventions, instrumental to facilitate shared decisions. When focused on adverse events in clinical trials, tools are needed to assess seriousness, causality and severity. As part of such a toolbox, the international Neonatal Consortium (INC) developed a first version of the neonatal adverse event severity scale (NAESS). This version underwent subsequent validation in retro-and prospective trials to assess its applicability and impact on the inter-observer variability. Regulators, sponsors and academic researchers also reported on the use of the NAESS in regulatory documents, trial protocols and study reports. In this paper, we aim to report on the trajectory, current status and impact of the NAESS score, on how stakeholders within INC assess its relevance, and on perspectives to further develop this tool.

Physiologically Based Pharmacokinetic Modeling in Neonates: Current Status and Future Perspectives

Rational drug use in special populations is a clinical problem that doctors and pharma-cists must consider seriously. Neonates are the most physiologically immature and vulnerable to drug dosing. There is a pronounced difference in the anatomical and physiological profiles be-tween neonates and older people, affecting the absorption, distribution, metabolism, and excretion of drugs in vivo, ultimately leading to changes in drug concentration. Thus, dose adjustments in neonates are necessary to achieve adequate therapeutic concentrations and avoid drug toxicity. Over the past few decades, modeling and simulation techniques, especially physiologically based pharmacokinetic (PBPK) modeling, have been increasingly used in pediatric drug development and clinical therapy. This rigorously designed and verified model can effectively compensate for the deficiencies of clinical trials in neonates, provide a valuable reference for clinical research design, and even replace some clinical trials to predict drug plasma concentrations in newborns. This review introduces previous findings regarding age-dependent physiological changes and pathological factors affecting neonatal pharmacokinetics, along with their research means. The application of PBPK modeling in neonatal pharmacokinetic studies of various medications is also reviewed. Based on this, we propose future perspectives on neonatal PBPK modeling and hope for its broader application.

A Callout for International Collaboration. Reply to Giger, E.V.; Tilen, R. Comment on "Shaniv et al. Neonatal Drug Formularies-A Global Scope. Children 2023, 10, 848"

We are very grateful that the global-scope paper on neonatal drug formularies has received a relevant amount of interest from the readership of the journal [...].

Acquired Brain Injuries Across the Perinatal Spectrum: Pathophysiology and Emerging Therapies

The development of the central nervous system can be directly disrupted by a variety of acquired factors, including infectious, inflammatory, hypoxic-ischemic, and toxic insults. Influences external to the fetus also impact neurodevelopment, including placental health, maternal comorbidities, adverse experiences, environmental exposures, and social determinants of health. Acquired perinatal brain insults tend to affect the developing brain in a stage-specific manner that reflects the susceptible cell types, developmental processes, and risk factors present at the time of the insult. In this review, we discuss the pathophysiology, neurodevelopmental outcomes, and management of common acquired perinatal brain conditions. In the fetal brain, we divide insults based on trimester, and in the postnatal brain, we focus on common pathologies that have a presentation dependent on gestational age at birth: white matter injury and germinal matrix hemorrhage/intraventricular hemorrhage in preterm infants and hypoxic-ischemic encephalopathy in term infants. Although specific treatments for fetal and newborn brain disorders are currently limited, we emphasize therapies in preclinical or early clinical phases of the development pipeline. The growing number of novel cell type- and stage-specific emerging therapies suggests that in the near future we may have a dramatically improved ability to treat acquired perinatal brain disorders and to mitigate the associated neurodevelopmental consequences.

Paediatric drug development and evaluation: Existing challenges and recommendations

Despite various international regulatory initiatives over the last 20 years, many challenges remain in the field of paediatric drug development and evaluation. Indeed, drug research and development is still focused essentially on adult indications, thereby excluding many paediatric patients, limiting the feasibility of trials and favouring competing developments. Off-label prescribing persists and the development of age-appropriate dosage forms for children remains limited. Against this background, the members of this panel (TR) recommend the launch of multi-partner exchange forums on specific topics in order to focus new drug research and development on the real, unmet medical needs of children and adolescents, and in keeping with the underlying mechanisms of action. Scientific information sharing and cooperation between stakeholders are also essential for defining reference evaluation methods in each medical field. These forums can be organised through existing paediatric facilities and research networks at the French and European level. The latter are specifically dedicated to paediatric research and can facilitate clinical trial implementation and patient enrolment. Moreover, specific grants and public/private partnerships are still needed to support studies on the repositioning of drugs in paediatric indications, and pharmacokinetic studies aimed at defining appropriate dosages. The development of new pharmaceutical forms, better suited for paediatric use, and the promotion of resulting innovations will stimulate future investments. Initiatives to gather observational safety and efficacy data following off-label and/or derogatory early access should also be encouraged to compensate for the lack of information available in these situations. Finally, the creation of Ethics Committees (EC) with a specific "mother-child" advisory expertise should be promoted to ensure that the current regulation (Jardé law in France) is implemented whilst also taking into account the paediatric specificities in medical trials.

Establishing evidence-based pharmacologic treatments for neonatal abstinence syndrome: A retrospective case study

Translation of research discoveries into health impact can take many years, creating delays in improving clinical outcomes. One approach to promoting timely translation is to examine successful cases in order to understand facilitators and strategies for overcoming barriers. We examined the development of evidence-based management for neonatal abstinence syndrome (NAS) at one academic medical center, with a primary focus on pharmacologic treatment. Despite a substantial increase in NAS case incidence starting in the early 2000s, significant sociocultural, policy, and regulatory barriers limited collaborative NAS research. Facilitators for translation encompassed: 1) pursuing research of societal interest, 2) building an effective interdisciplinary team, 3) intentionally linking clinical, research, and advocacy efforts, 4) broad stakeholder engagement across clinical, policy, and research arenas, and 5) leveraging local resources. Challenges included lack of commercially available U.S. Food and Drug Administration approved neonatal drug formulations, legal and regulatory barriers related to off-label and illicit use of opioids, recruitment for a treatment associated with drug withdrawal syndromes, misalignment of research design needs with real-world scenarios, and episodic funding. Benefits of successful translation included improvements in clinical care, reduced healthcare costs related to NAS, and enhanced legislative, policy, and research strategies to support broader neonatal investigations.

Current and future physiologically based pharmacokinetic (PBPK) modeling approaches to optimize pharmacotherapy in preterm neonates

INTRODUCTION

There is a need for structured approaches to inform on pharmacotherapy in preterm neonates. With their proven track record up to regulatory acceptance, physiologically based pharmacokinetic (PBPK) modeling and simulation provide such a structured approach, and hold the promise to support drug development in preterm neonates.

AREAS COVERED

Compared to the general and pediatric use of PBPK modeling, its use to inform pharmacotherapy in preterms is limited. Using a systematic search (PBPK + preterm), we retained 25 records (20 research papers, 2 letters, 3 abstracts). We subsequently collated the published information on PBPK software packages (PK-Sim®, Simcyp®), and their applications and optimization efforts in preterm neonates. It is encouraging that these applications cover a broad range of scenarios (pharmacokinetic-dynamic analyses, drug-drug interactions, developmental pharmacogenetics, lactation related exposure) and compounds (small molecules, proteins). Furthermore, specific compartments (cerebrospinal fluid, tissue) or (patho)physiologic processes (cardiac output, biliary excretion, first pass metabolism) are considered.

EXPERT OPINION

Knowledge gaps exist, giving rise to various levels of model uncertainty in PBPK applications in preterm neonates. To improve this setting, we need cross talk between clinicians and modelers to generate and integrate knowledge (PK datasets, system knowledge, maturational physiology and pathophysiology) to further refine PBPK models.

From immature pharmacotherapy towards pharmacotherapy of the immature

To truly attain effective and safe pharmacotherapy, the similarities and dissimilarities in physiology between micro-preemies and extreme preterm infants should be explored. The higher incidence of pulmonary hypertension and presence of adrenal insufficiency of prematurity in micro-preemies hereby serve as illustrations. The current limited data on pharmacokinetics, -dynamics and safety reflect the obvious need to collect such data, and to tailor modelling tools to their physiology and needs. Drug utilization hereby mirrors different needs and practices and may serve to guide prioritization decisions. Physiological data, combined with even limited observations on pharmacokinetics and -dynamics can be translated to effective modelling tools to attain effective and safe pharmacotherapy. We therefore discuss how valid research tools in pharmacology like physiology-based pharmacokinetic models can be developed, and how clinicians can contribute to such efforts, with the overarching aim to enable this shift from immature pharmacotherapy to pharmacotherapy for the immature.

Challenges and opportunities for improving access to approved neonatal drugs and devices

Neonatal drug and device development has lagged behind other patient populations. Oftentimes, providers are using drugs and devices without adequate study of safety and efficacy. Neonates deserve dedicated drug and device development programs, which will require novel approaches and unique collaborations between multiple key stakeholders. Legislative efforts, infrastructure, clinical trial methodology, and international collaborations have all contributed to improvements in neonatal drug and device development, but more work is still needed. Leadership from neonatologists, clinical care providers, and parents is essential to implement needed changes.

QTc Intervals Are Prolonged in Late Preterm and Term Neonates during Therapeutic Hypothermia but Normalize Afterwards

BACKGROUND

There are anecdotal reports on reversible QTc prolongation during therapeutic hypothermia (TH) for moderate to severe neonatal encephalopathy after asphyxia. As the QTc interval is a relevant biomarker for pharmacovigilance during medication development, a structured search and review on published neonatal QTc values to generate reference values is warranted to facilate medication development in this specific population.

METHODS

A structured search and literature assessment (PubMed, Embase, and Google Scholar) with 'Newborn/Infant, QT and hypothermia' was conducted (October 2021). Retrieved individual values were converted to QTc (Bazett) over postnatal age (day 1-7).

RESULTS

We retrieved 94 QTc intervals (during TH (n = 50, until day 3) or subsequent normothermia (n = 44, day 4-7)) in 33 neonates from 6 publications. The median (range) of QTc intervals during TH was 508 (430-678), and 410 (317-540) ms afterwards (difference 98 ms, or +28 ms/°C decrease). Four additional cohorts (without individual QTc intervals) confirmed the pattern and magnitude of the effect of body temperature on the QTc interval.

CONCLUSIONS

We highlighted a relevant non-maturational covariate (°C dependent TH) and generated reference values for the QTc interval in this specific neonatal subpopulation. This knowledge on QTc during TH should be considered and integrated in neonatal medication development.

Why are certain age bands used for children in paediatric studies of medicines?

Rational prescribing of medicines requires evidence from clinical trials on efficacy, safety and the dose to be prescribed, based on clinical trials. Regulatory authorities assess these data and information is included in the approved summary of product characteristics. Regulatory guidelines on clinical investigation of medicinal products in the paediatric population generally propose that studies are done in defined age groups but advise that any classification of the paediatric population into age categories is to some extent arbitrary or that the age groups are intended only as a guide. The pharmaceutical companies tend to plan their studies using age groups the regulatory guidelines suggest, to avoid problems when applying for marketing authorisation. These age bands end up in the paediatric label, and consequently into national paediatric formularies. The age bands of the most commonly used age-subsets: neonates, infant/toddlers, children and adolescents, are more historical than based on physiology or normal development of children. Particularly problematic are the age bands for neonates and adolescents. The age of 12 years separating children from adolescents, and the upper limit of the adolescents set by the definition of paediatric age in healthcare, which varies according to the region, are particularly questionable. Modern pharmacometric methods (modelling and simulation) are being increasingly used in paediatric drug development and may allow assessment of growth and/or development as continuous covariables. Maybe time has come to reconsider the rational of the currently used age bands.

Model-Informed Pediatric Drug Development: Application of Pharmacometrics to Define the Right Dose for Children

One of the biggest challenges in pediatric drug development is defining a safe and effective dose in pediatric populations, which span across a wide age and development range from neonates to adolescents. Model-informed drug development approaches are particularly suited to address knowledge gaps including data leveraging to increase the success of pediatric studies. Considering the often limited number of patients available for study and logistic difficulties to collect the necessary data in pediatric populations, the application of pharmacometrics and modeling and simulation techniques can improve clinical trial efficiency, increase the probability of regulatory success, and optimize therapeutic individualization in support of dedicated trials. This review describes the state of pediatric model-informed drug development to define the right dose for children and provides suggestions for future development.

The European Medicines Agency Experience With Pediatric Dose Selection

Getting the right dose regimen for children and adolescents is important but poses great scientific, practical, and ethical challenges. At the same time, the availability of data in adults is a huge advantage and needs to be used optimally when designing studies in children and analyzing pediatric data. Furthermore, the processes of maturation and growth are always key when selecting doses for children. All the above make study adaptations and model-informed approaches imperative for dose exposure-response characterization and dose selection in children. This article summarizes the experience gained in the European Medicines Agency on this topic and proposes some general guiding principles for defining objectives, study designs, and methodology tools for pediatric dose selection.

Considerations for Drug Dosing in Premature Infants

In premature infants, effective and safe drug therapy depends on optimal dose selection and requires a thorough understanding of the underlying disease(s) of these fragile infants as well as the pharmacokinetics and pharmacodynamics of the drugs selected to treat their diseases. Differences in gestational and postnatal age or weight are the major determinants of the observed variability in drug disposition and effect in these infants. This article presents an outline on how to translate the results of a population pharmacokinetic/pharmacodynamic study into rational dosing regimens, and how physiologically based pharmacokinetic modeling, electronic health records, and the abundantly available data of vital functions of premature infants during their stay in the neonatal intensive care unit for evaluation of their pharmacotherapy can be used to tailor the most safe and effective dose in these infants.

Population Model of Serum Creatinine as Time-Dependent Covariate in Neonates

Serum creatinine (sCr) is a commonly measured biomarker to estimate glomerular filtration rate (GFR) and therefore widely used as a covariate in population pharmacokinetic models of renally excreted drugs. In neonates, sCr dynamically changes during the first few weeks after birth. Missing covariates are a common problem in pharmacokinetic modeling of neonates due to the limited availability of blood sampling in number and volume. The objective of this work is to develop a parsimonious population model describing time courses of sCr in neonates with the intent to be incorporated into pharmacokinetic models of various drugs where sCr values are sparse or missing. The data for model development consisted of sCr measurements in 1080 newborns with a gestational age of 24-42 weeks. The model is based on a pharmacokinetic model of sCr that involves GFR, backflow of creatinine from the renal tubules, and urinary flow. Gestational age is the only covariate explaining between-subject variability of sCr. The model adequately describes distinct features of the sCr time course such as a peak and decline to a plateau. For a neonate with a GA of 35 weeks, the typical value of sCr at birth was 0.584 mg/dL, the peak (0.794 mg/dL) occurred 2.3 days after birth, to reach a plateau of 0.255 mg/dL approximately after 24.7 days. Model simulations reveal that in neonates with a similar postnatal age, sCr decreases with increasing GA. In summary, our model is designed to be a part of full random effects pharmacokinetic models where sCr is a significant covariate.

Application of Physiologically Based Pharmacokinetic-Pharmacodynamic Modeling in Preterm Neonates to Guide Gentamicin Dosing Decisions and Predict Antibacterial Effect

Clinical studies in preterm neonates are rarely performed due to ethical concerns and difficulties associated with trials and recruitment. Consequently, dose selection in this population is primarily empirical. Scaling neonatal doses from adult doses does not account for developmental changes and may not accurately predict drug kinetics. This is especially important for gentamicin, a narrow therapeutic index aminoglycoside antibiotic. While gentamicin's bactericidal effect is associated with its peak plasma concentration, keeping trough concentrations below 1 µg/mL prevents toxicity and also helps to counteract adaptive resistance in bacteria such as Escherichia coli. In this study, physiologically based pharmacokinetic-pharmacodynamic (PBPK-PD) modeling was used to support and/or guide dosing decisions and to predict the antibacterial effect in preterm neonates. A gentamicin PBPK model was successfully verified in healthy adults and preterm neonates across all gestational ages. Clinical data from a neonatal intensive care unit at NYU Langone Hospital-Long Island was used to identify dosing regimens associated with increased incidence of elevated gentamicin trough concentrations in different preterm patient cohorts. Model predictions demonstrated that a higher dose with an extended-dosing interval (every 36 hours) in neonates with a postmenstrual age of 30 to 34 weeks and ≥35 weeks, with postnatal age 8 to 28 days and 0 to 7 days, respectively, were more likely to have a trough <1 µg/mL when compared with once-daily (every 24 hours) dosing. PBPK-PD modeling suggested that a higher dose administered every 36 hours may provide effective antibacterial therapy.

Dose-Related Adverse Drug Events in Neonates: Recognition and Assessment

The efficacy and safety of a drug is dose or exposure related, and both are used to assess the benefit-risk balance of a given drug and ultimately to decide on the specific drug license, including its dose and indication(s). Unfortunately, both efficacy and safety are much more difficult to establish in neonates, resulting in very few drugs licensed for use in this vulnerable population. This review will focus on dose-related adverse events in neonates. Besides the regulatory classification on seriousness, adverse event assessment includes aspects related to signal detection, causality, and severity. Disentangling confounders from truly dose-related adverse drug events remains a major challenge, as illustrated for drug-induced renal impairment, drug-induced liver injury, and neurodevelopmental outcome. Causality assessment, using either routine tools (Naranjo algorithm, World Health Organization's Uppsala Monitoring Center causality tool) or a Naranjo algorithm tailored to neonates, still does not sufficiently and reliably document causality in neonates. Finally, very recently, a first neonatal severity-grading tool for neonates has been developed. Following the development of advanced pharmacokinetic approaches and techniques to predict and assess drug exposure, additional efforts are needed to truly and fully assess dose adverse drug events. To further operationalize the recently developed tools on causality and severity, reference databases on a palette of biomarkers and outcome variables and their covariates are an obvious next step. These databases should subsequently be integrated in modeling efforts to truly explore safety outcome, including aspects associated with or caused by drug dose or exposure.

Preterm Physiologically Based Pharmacokinetic Model. Part II: Applications of the Model to Predict Drug Pharmacokinetics in the Preterm Population

BACKGROUND

Preterm neonates are usually not part of a traditional drug development programme, however they are frequently administered medicines. Developing modelling and simulation tools, such as physiologically based pharmacokinetic (PBPK) models that incorporate developmental physiology and maturation of drug metabolism, can be used to predict drug exposure in this group of patients, and may help to optimize drug dose adjustment.

OBJECTIVE

The aim of this study was to assess and verify the predictability of a preterm PBPK model using compounds that undergo diverse renal and/or hepatic clearance based on the knowledge of their disposition in adults.

METHODS

A PBPK model was developed in the Simcyp Simulator V17 to predict the pharmacokinetics (PK) of drugs in preterm neonates. Drug parameters for alfentanil, midazolam, caffeine, ibuprofen, gentamicin and vancomycin were collated from the literature. Predicted PK parameters and profiles were compared against the observed data.

RESULTS

The preterm PBPK model predicted the PK changes of the six compounds using ontogeny functions for cytochrome P450 (CYP) 1A2, CYP2C9 and CYP3A4 after oral and intravenous administrations. For gentamicin and vancomycin, the maturation of renal function was able to predict the exposure of these two compounds after intravenous administration. All PK parameter predictions were within a twofold error criteria.

CONCLUSION

While the developed preterm model for the prediction of PK behaviour in preterm patients is not intended to replace clinical studies, it can potentially help with deciding on first-time dosing in this population and study design in the absence of clinical data.

Adaptive Focused Acoustics™ for Nanosuspensions to Enable Pharmacology Assessment of Poorly Soluble Molecules in Lead Optimization

In Drug Discovery, pharmacology studies often require benign formulation compositions for safe administration in animal models. Here, we applied Adaptive Focused Acoustics™ (AFA) to a molecular scaffold with challenging physicochemical properties for intraperitoneal administration. Nanosuspensions can be prepared at small scales and provide broad applicability. Our results show that nanosuspension formulations prepared by AFA have improved PK performance relative to a DMSO solution formulation that is prone to precipitation in-vivo.

The conect4children (c4c) Consortium: Potential for Improving European Clinical Research into Medicines for Children

The need for information about new and existing drugs used in children was recognized in the European Union (EU) with the implementation of the Paediatric Regulation in 2007. In 2017, the 10-year review of the Paediatric Regulation identified barriers to the conduct of clinical trials, including delays in setting up and completing paediatric trials. Across Europe, the difficulties with clinical research are compounded by variation within countries and between countries. Ethics and regulatory review have national specificities. This paper describes the Collaborative Network for European Clinical Trials for Children (conect4children, c4c), which addresses selected difficulties in the design and conduct of paediatric clinical trials. c4c is a time-limited public–private consortium funded by the Innovative Medicines Initiative (IMI2). The elements of c4c are as follows: expert advice providing input on study design and/or paediatric development programmes (including patient involvement activities); a network of sites following harmonised procedures coordinated by National Hubs and a single point of contact for Europe; a facility for education and training for sites and trial teams; and support for managing data used by the network and a common paediatric data dictionary. c4c does not sponsor trials. c4c is taking a phased approach with careful piloting through industry and non-industry studies intended to demonstrate the viability of the network (proof-of-viability studies). c4c uses a co-design approach involving industry and academics within a clearly defined scope. A sustainable, successor organization open to all potential service users will be open for business before the end of IMI2 funding in 2024.

Amikacin or Vancomycin Exposure Alters the Postnatal Serum Creatinine Dynamics in Extreme Low Birth Weight Neonates

Background: Disentangling renal adverse drug reactions from confounders remains a major challenge to assess causality and severity in neonates, with additional limitations related to the available tools (modified Kidney Disease Improving Global Outcome, or Division of Microbiology and Infectious Diseases pediatric toxicity table). Vancomycin and amikacin are nephrotoxic while still often prescribed in neonates. We selected these compounds to assess their impact on creatinine dynamics as a sensitive tool to detect a renal impairment signal. Methods: A recently developed dynamical model that characterized serum creatinine concentrations of 217 extremely low birth weight (<1000 g, ELBW) neonates (4036 observations) was enhanced with data on vancomycin and/or amikacin exposure to identify a potential effect of antibiotic exposure by nonlinear mixed-effects modelling. Results: Seventy-seven percent of ELBW patients were exposed to either vancomycin or amikacin. Antibiotic exposure resulted in a modest increase in serum creatinine and a transient decrease in creatinine clearance. The serum creatinine increase was dependent on gestational age, illustrated by a decrease with 56% in difference in serum creatinine between a 24 or 32-week old neonate, when exposed in the 3rd week after birth. Conclusions: A previously described model was used to explore and quantify the impact of amikacin or vancomycin exposure on creatinine dynamics. Such tools serve to explore minor changes, or compare minor differences between treatment modalities.

Clinical Research in Neonates: Redesigning the Informed Consent Process in the Digital Era

Background: Currently, many initiatives are devoted to optimizing informed consent for participation in clinical research. Due to the digital transformation in health care, a shift toward electronic informed consent (eIC) has been fostered. However, empirical evidence on how to implement eIC in clinical research involving neonates is lacking. Methods: Semi-structured interviews were conducted with 31 health care professionals active in Belgium or the Netherlands. All health care professionals had experience in conducting clinical research involving neonates. Interviews were audio-recorded, transcribed and analyzed using the framework method. Results: Interviewees generally supported the use of eIC in clinical research involving neonates. For example, eIC could enable parents to receive study feedback via the eIC system. Requirements were expressed for parental involvement to decide on which feedback would be appropriate to return. Moreover, experts specialized in presenting information and designing electronic systems should be involved. Broad consensus among health care professionals indicates that the face-to-face-interaction between parents and the research team is vital to establish a relationship of trust. Therefore, it is necessary that the use of eIC runs alongside personal interactions with the parents. Concerns were raised about the accessibility of eIC to parents. For this reason, it was suggested that parents should always be given the possibility to read and sign a paper-based informed consent form or to use eIC. Conclusions: Health care professionals' views indicate that the use of eIC in clinical research with neonates may offer various opportunities. Further development and implementation will require a multi-stakeholder approach.

Cangrelor PK/PD analysis in post-operative neonatal cardiac patients at risk for thrombosis

Essentials An optimal therapeutic strategy has yet to be established to prevent early shunt thrombosis. A phase 1 study of cangrelor was performed in neonates after palliation of congenital heart disease. PD endpoint of >90% platelet inhibition in 60% of patients was achieved at 0.5 µg/kg/min dosing. No serious adverse events related to drug administration were observed, including bleeding. ABSTRACT: Background Systemic-to-pulmonary artery shunt thrombosis is a significant cause of early postoperative mortality in neonates after palliation of congenital heart disease. In the context of thromboprophylaxis, an optimal therapeutic strategy has yet to be established before aspirin administration. Cangrelor, a fast-acting, reversible P2Y12 inhibitor, may fill this unmet need. Objectives To evaluate the pharmacokinetics (PK), pharmacodynamics (PD), and safety of cangrelor in neonates undergoing stage 1 palliation. Methods This prospective, open-label, single-arm study evaluated two cangrelor dosing cohorts following placement of a systemic-to-pulmonary artery shunt, right ventricle-to-pulmonary artery shunt, or ductal stent. Drug concentrations and platelet reactivity, assessed by light transmission aggregometry and in microfluidic assays (MF), were measured. Results Twenty-two patients were consented and 15 received a 1-hour infusion of cangrelor at either 0.5 µg/kg/min (cohort 1) or 0.25 µg/kg/min (cohort 2). Whereas the primary PD endpoint was achieved at the higher dose (ie, reduction in maximal platelet aggregation by ≥90% in 60% of participants), only 29% of those in cohort 2 attained this goal. Comparable and statistically significant results were obtained in MF assays (P < .0001 vs. baseline). Drug levels during infusion were 3-fold higher in cohort 1 vs. cohort 2 (P < .001). Most participants (70%) had undetectable drug levels by 10 minutes postinfusion with full recovery in platelet function at 1 hour. No drug-related bleeding events occurred. Conclusions Favorable PK/PD properties of cangrelor 0.5 µg/kg/min dosing and safety profile warrant further evaluation in neonates following palliative cardiac procedures.

The Neonatal and Juvenile Pig in Pediatric Drug Discovery and Development

Pharmacotherapy in pediatric patients is challenging in view of the maturation of organ systems and processes that affect pharmacokinetics and pharmacodynamics. Especially for the youngest age groups and for pediatric-only indications, neonatal and juvenile animal models can be useful to assess drug safety and to better understand the mechanisms of diseases or conditions. In this respect, the use of neonatal and juvenile pigs in the field of pediatric drug discovery and development is promising, although still limited at this point. This review summarizes the comparative postnatal development of pigs and humans and discusses the advantages of the juvenile pig in view of developmental pharmacology, pediatric diseases, drug discovery and drug safety testing. Furthermore, limitations and unexplored aspects of this large animal model are covered. At this point in time, the potential of the neonatal and juvenile pig as nonclinical safety models for pediatric drug development is underexplored.

How to introduce MSC-based therapy for the developing lung safely into clinical care?

Extreme prematurity is associated with an increased risk to develop bronchopulmonary dysplasia (BPD). Severe BPD is associated with a significant long-term burden for the affected infant, families and society. Currently there are limited prevention and treatment options. Regenerative approaches using mesenchymal stromal cells (MSC) are associated with promising benefits in animal experiments. First clinical studies, using MSC in humans, suggest safety. To accelerate the process of bench to bed-side development of MSC-based therapies, a global and collaborative approach is needed that includes all key stakeholders. Results of a workshop that was held during the Pediatric Academic Societies meeting in 2019 are summarized. A roadmap is provided discussing next steps of bringing MSC-based interventions into clinical practice.

Approaches to Dose Finding in Neonates, Illustrating the Variability between Neonatal Drug Development Programs

Drug dosing in neonates should be based on integrated knowledge concerning the disease to be treated, the physiological characteristics of the neonate, and the pharmacokinetics (PK) and pharmacodynamics (PD) of a given drug. It is critically important that all sources of information be leveraged to optimize dose selection for neonates. Sources may include data from adult studies, pediatric studies, non-clinical (juvenile) animal models, in vitro studies, and in silico models. Depending on the drug development program, each of these modalities could be used to varying degrees and with varying levels of confidence to guide dosing. This paper aims to illustrate the variability between neonatal drug development programs for neonatal diseases that are similar to those seen in other populations (meropenem), neonatal diseases related but not similar to pediatric or adult populations (clopidogrel, thyroid hormone), and diseases unique to neonates (caffeine, surfactant). Extrapolation of efficacy from older children or adults to neonates is infrequently used. Even if a disease process is similar between neonates and children or adults, such as with anti-infectives, additional dosing and safety information will be necessary for labeling, recognizing that dosing in neonates is confounded by maturational PK in addition to body size.

Respiratory medication use in extremely premature (<29 weeks) infants during initial NICU hospitalization: Results from the prematurity and respiratory outcomes program

BACKGROUND

The use of medications to treat respiratory conditions of extreme prematurity is often based upon studies of adults or children over 2 years of age. Little is known about the spectrum of medications used or dosing ranges. To inform the design of future studies, we conducted a prospective analysis of respiratory medication exposure among 832 extremely low gestational age neonates.

METHODS

The prematurity and respiratory outcomes program (PROP) enrolled neonates less than 29-week gestation from 6 centers incorporating 13 clinical sites. We collected recorded daily "respiratory" medications given along with dosing information through 40-week postmenstrual age or neonatal intensive care unit discharge if earlier.

RESULTS

PROP participants were exposed to a wide range of respiratory medications, often at doses beyond published recommendations. Nearly 50% received caffeine and furosemide beyond published recommendations for cumulative dose. Those who developed bronchopulmonary dysplasia were more likely to receive treatment with respiratory medications. However, more than 30% of PROP subjects that did not develop bronchopulmonary dysplasia also were treated with diuretics, systemic steroids, and other respiratory medications.

CONCLUSION

Extremely preterm neonates in PROP were exposed to high doses of medications at levels known to generate significant adverse effects. With limited evidence for efficacy, there is an urgent need for controlled trials in this vulnerable patient population.

Renal Precision Medicine in Neonates and Acute Kidney Injury: How to Convert a Cloud of Creatinine Observations to Support Clinical Decisions

Renal precision medicine in neonates is useful to support decision making on pharmacotherapy, signal detection of adverse (drug) events, and individual prediction of short- and long-term prognosis. To estimate kidney function or glomerular filtration rate (GFR), the most commonly measured and readily accessible biomarker is serum creatinine (S_cr). However, there is extensive variability in S_cr observations and GFR estimates within the neonatal population, because of developmental physiology and superimposed pathology. Furthermore, assay related differences still matter for S_cr, but also exist for Cystatin C. Observations in extreme low birth weight (ELBW) and term asphyxiated neonates will illustrate how renal precision medicine contributes to neonatal precision medicine. When the Kidney Disease Improving Global Outcome (KDIGO) definition of acute kidney injury (AKI) is used, this results in an incidence up to 50% in ELBW neonates, associated with increased mortality and morbidity. However, urine output criteria needed adaptations to broader time intervals or weight trends, while S_cr and its trends do not provide sufficient detail on kidney function between ELBW neonates. Instead, we suggest to use assay-specific centile S_cr values to better describe postnatal trends and have illustrated its relevance by quantifying an adverse drug event (ibuprofen) and by explaining individual amikacin clearance. Term asphyxiated neonates also commonly display AKI. While oliguria is a specific AKI indicator, the majority of term asphyxiated cases are non-oliguric. Asphyxia results in a clinical significant-commonly transient-mean GFR decrease (-50%) with a lower renal drug elimination. But there is still major (unexplained) inter-individual variability in GFR and subsequent renal drug elimination between these asphyxiated neonates. Recently, the Baby-NINJA (nephrotoxic injury negated by just-in-time action) study provided evidence on the concept that a focus on nephrotoxic injury negation has a significant impact on AKI incidence and severity. It is hereby important to realize that follow-up should not be discontinued at discharge, as there are concerns about long-term renal outcome. These illustrations suggest that integration of renal (patho)physiology into neonatal precision medicine are an important tool to improve contemporary neonatal care, not only for the short-term but also with a positive health impact throughout life.

Development of a neonatal adverse event severity scale through a Delphi consensus approach

BACKGROUND

Assessment of the seriousness, expectedness and causality are necessary for any adverse event (AE) in a clinical trial. In addition, assessing AE severity helps determine the importance of the AE in the clinical setting. Standardisation of AE severity criteria could make safety information more reliable and comparable across trials. Although standardised AE severity scales have been developed in other research fields, they are not suitable for use in neonates. The development of an AE severity scale to facilitate the conduct and interpretation of neonatal clinical trials is therefore urgently needed.

METHODS

A stepwise consensus process was undertaken within the International Neonatal Consortium (INC) with input from all relevant stakeholders. The consensus process included several rounds of surveys (based on a Delphi approach), face-to-face meetings and a pilot validation.

RESULTS

Neonatal AE severity was classified by five grades (mild, moderate, severe, life threatening or death). AE severity in neonates was defined by the effect of the AE on age appropriate behaviour, basal physiological functions and care changes in response to the AE. Pilot validation of the generic criteria revealed κ=0.23 and guided further refinement. This generic scale was applied to 35 typical and common neonatal AEs resulting in the INC neonatal AE severity scale (NAESS) V.1.0, which is now publicly available.

DISCUSSION

The INC NAESS is an ongoing effort that will be continuously updated. Future perspectives include further validation and the development of a training module for users.

Development of a neonatal adverse event severity scale through a Delphi consensus approach

BACKGROUND

Assessment of the seriousness, expectedness and causality are necessary for any adverse event (AE) in a clinical trial. In addition, assessing AE severity helps determine the importance of the AE in the clinical setting. Standardisation of AE severity criteria could make safety information more reliable and comparable across trials. Although standardised AE severity scales have been developed in other research fields, they are not suitable for use in neonates. The development of an AE severity scale to facilitate the conduct and interpretation of neonatal clinical trials is therefore urgently needed.

METHODS

A stepwise consensus process was undertaken within the International Neonatal Consortium (INC) with input from all relevant stakeholders. The consensus process included several rounds of surveys (based on a Delphi approach), face-to-face meetings and a pilot validation.

RESULTS

Neonatal AE severity was classified by five grades (mild, moderate, severe, life threatening or death). AE severity in neonates was defined by the effect of the AE on age appropriate behaviour, basal physiological functions and care changes in response to the AE. Pilot validation of the generic criteria revealed κ=0.23 and guided further refinement. This generic scale was applied to 35 typical and common neonatal AEs resulting in the INC neonatal AE severity scale (NAESS) V.1.0, which is now publicly available.

DISCUSSION

The INC NAESS is an ongoing effort that will be continuously updated. Future perspectives include further validation and the development of a training module for users.

Pharmacokinetic modelling and Bayesian estimation-assisted decision tools to optimize vancomycin dosage in neonates: only one piece of the puzzle

Introduction: Vancomycin is commonly administered to neonates, while observational data on therapeutic drug monitoring (TDM, trough levels) suggest that vancomycin exposure and dosage remain substandard. Area covered: Data on vancomycin pharmacokinetics (PK) and its covariates are abundant. Consequently, modeling is an obvious tool to improve targeted exposure, with a shift from TDM trough levels to area under the curve (AUC_24h) targets, as in adults. Continuous administration appeared as a practice to facilitate AUC_24h target attainment, while Bayesian model-supported targeting emerged as a novel tool. However, the AUC_24h/MIC (minimal inhibitory concentration) target itself should consider neonate-specific aspects (bloodstream infections, coagulase-negative staphylococci, protein binding, underexplored causes of variability, like assays, preparation and administration inaccuracies, or missing covariates). Expert opinion: To improve targeted exposure in neonates, initial vancomycin prescription should be based on 'a priori model-based individual dosing' using validated dosing regimens, followed by further tailoring by dosing optimization applying Bayesian estimation-assisted TDM. Future research should focus on the feasibility to integrate these tools (individualized dosing, Bayesian models) in clinical practice, and to perform PK/PD studies in the relevant animal models and human neonatal setting (coagulase-negative staphylococci, bloodstream infections).

Pediatric Age Groups and Approach to Studies

Pediatric clinical trials are often requested according to specific age ranges. In the past and still today, these ages may correspond to developmental stages, such as newborn, infancy, childhood, and adolescence. Selection of ages for pediatric participation in medication studies should correspond to ages of rapid changes in pharmacokinetics and pharmacodynamics. Age-related changes in several enzymes involved in drug metabolism and glomerular filtration are described as examples of optimal ages for study of specific drugs according to their pathways of disposition.

Collaboration in Regulatory Science to Facilitate Therapeutic Development for Neonates

BACKGROUND

Historically, neonatal therapeutic interventions were derived from adult therapeutics, and tragedies resulting from this approach have demonstrated differences in the pathophysiologic and developmental processes between neonates and older patients. Over the past 3 decades, researchers and collaborative research networks have made progress in the systematic evaluation of neonatal therapies, yet most neonatal therapeutic products have been incompletely assessed for safety and efficacy, and remain unlabeled and unapproved.

APPROACH

This work describes the legislative initiatives that have stimulated an increase in pediatric and neonatal studies. It highlights examples of successful neonatal drug studies that have resulted in informative neonatal labeling changes, as well as studies that have produced incomplete information. Strategies that support the design of successful studies, including targeting specific subpopulations, modeling and simulation to inform dose selection, innovative design strategies, biomarkers, and endpoints are discussed. Multi-stakeholder consortia such as the International Neonatal Consortium (INC), are working to improve the tools needed for the development of neonatal therapies. These research tools may be used by trial networks to inform consistent and efficient multicenter studies.

CONCLUSION

More data are needed to support safe and effective use of drugs in neonates, and to obtain these data, a thorough understanding of pathophysiology, drug disposition, biomarkers, and clinically-meaningful endpoints is required. This information will be derived from clinical trials, registries, real-world evidence, and the medical literature. Collaboration of consortia and the development of research networks are essential to achieving these goals.

Challenges in Designing Clinical Trials to Test New Drugs in the Pregnant Woman and Fetus

The need for new drugs in pregnancy is widely recognized. This review identifies several unique challenges and describes some solutions. Specific studies and drug development programs need careful planning that accounts for the needs of regulatory agencies. The perinatal (obstetric/pediatric) community needs to establish collaborations to develop methodologies, to facilitate data sharing, and to lobby for research and access to medicines. There is a need to gather and present information that promotes proportionate judgments of the balance between potential benefits and risks. This will require researchers to look beyond their traditional ways of working.

Recommendations for the design of therapeutic trials for neonatal seizures

Although seizures have a higher incidence in neonates than any other age group and are associated with significant mortality and neurodevelopmental disability, treatment is largely guided by physician preference and tradition, due to a lack of data from well-designed clinical trials. There is increasing interest in conducting trials of novel drugs to treat neonatal seizures, but the unique characteristics of this disorder and patient population require special consideration with regard to trial design. The Critical Path Institute formed a global working group of experts and key stakeholders from academia, the pharmaceutical industry, regulatory agencies, neonatal nurse associations, and patient advocacy groups to develop consensus recommendations for design of clinical trials to treat neonatal seizures. The broad expertise and perspectives of this group were invaluable in developing recommendations addressing: (1) use of neonate-specific adaptive trial designs, (2) inclusion/exclusion criteria, (3) stratification and randomization, (4) statistical analysis, (5) safety monitoring, and (6) definitions of important outcomes. The guidelines are based on available literature and expert consensus, pharmacokinetic analyses, ethical considerations, and parental concerns. These recommendations will ultimately facilitate development of a Master Protocol and design of efficient and successful drug trials to improve the treatment and outcome for this highly vulnerable population.

Neonates are not just little children and need more finesse in dosing of antibiotics

OBJECTIVES

Neonates are not just little children. They need more finesse in decisions on when to treat, which antibiotics to use and how to dose these antibiotics.

METHODS

Representative compounds of three major classes of antibiotics (beta-lactams, aminoglycosides, glycopeptides) are discussed in a narrative review to illustrate the recent progress in the knowledge on PK and its covariates (how to dose).

RESULTS

This knowledge can subsequently be converted to targeted exposure dosing regimens. This is because it is reasonable to postulate that pharmacodynamics (PD) of antibiotics are similar in neonates to that in other populations if a similar concentration-time profile and targeted exposure are attained. However, this approach has its limitations, since the clinical response may be different in neonates because of maturational differences in innate immunity or toxicity. These dosing regimens should at least be validated.

CONCLUSION

Relevant information on the PK of antibiotics and its covariates have been generated, but the next steps are to validate the dosing regimens suggested, and consider more sophisticated dosing regimens. This approach should subsequently pave the way to conduct comparative studies to assess the efficacy and safety of these commonly used drugs in neonates.

Making Medicines Baby Size: The Challenges in Bridging the Formulation Gap in Neonatal Medicine

The development of age-appropriate formulations should focus on dosage forms that can deliver variable yet accurate doses that are safe and acceptable to the child, are matched to his/her development and ability, and avoid medication errors. However, in the past decade, the medication needs of neonates have largely been neglected. The aim of this review is to expand on what differentiates the needs of preterm and term neonates from those of the older paediatric subsets, in terms of environment of care, ability to measure and administer the dose (from the perspective of the patient and carer, the routes of administration, the device and the product), neonatal biopharmaceutics and regulatory challenges. This review offers insight into those challenges posed by the formulation of medicinal products for neonatal patients in order to support the development of clinically relevant products.