Quantification of Fluid Volume and Distribution in the Paediatric Colon via Magnetic Resonance Imaging

Previous studies have used magnetic resonance imaging (MRI) to quantify the fluid in the stomach and small intestine of children, and the stomach, small intestine and colon of adults. This is the first study to quantify fluid volumes and distribution using MRI in the paediatric colon. MRI datasets from 28 fasted (aged 0–15 years) and 18 fluid-fed (aged 10–16 years) paediatric participants were acquired during routine clinical care. A series of 2D- and 3D-based software protocols were used to measure colonic fluid volume and localisation. The paediatric colon contained a mean volume of 22.5 mL ± 41.3 mL fluid, (range 0–167.5 mL, median volume 0.80 mL) in 15.5 ± 17.5 discreet fluid pockets (median 12). The proportion of the fluid pockets larger than 1 mL was 9.6%, which contributed to 94.5% of the total fluid volume observed. No correlation was detected between all-ages and colonic fluid volume, nor was a difference in colonic fluid volumes observed based on sex, fed state or age group based on ICH-classifications. This study quantified fluid volumes within the paediatric colon, and these data will aid and accelerate the development of biorelevant tools to progress paediatric drug development for colon-targeting formulations.

Drug Safety in Translational Paediatric Research: Practical Points to Consider for Paediatric Safety Profiling and Protocol Development: A Scoping Review

Translational paediatric drug development includes the exchange between basic, clinical and population-based research to improve the health of children. This includes the assessment of treatment related risks and their management. The objectives of this scoping review were to search and summarise the literature for practical guidance on how to establish a paediatric safety specification and its integration into a paediatric protocol. PubMed, Embase, Web of Science, and websites of regulatory authorities and learned societies were searched (up to 31 December 2020). Retrieved citations were screened and full texts reviewed where applicable. A total of 3480 publications were retrieved. No article was identified providing practical guidance. An introduction to the practical aspects of paediatric safety profiling and protocol development is provided by combining health authority and learned society guidelines with the specifics of paediatric research. The paediatric safety specification informs paediatric protocol development by, for example, highlighting the need for a pharmacokinetic study prior to a paediatric trial. It also informs safety related protocol sections such as exclusion criteria, safety monitoring and risk management. In conclusion, safety related protocol sections require an understanding of the paediatric safety specification. Safety data from carefully planned paediatric research provide valuable information for children, parents and healthcare providers.

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.

Phase 0, Including Microdosing Approaches: Applying the Three Rs and Increasing the Efficiency of Human Drug Development

Phase 0 approaches, including microdosing, involve the use of sub-therapeutic exposures to the tested drugs, thus enabling safer, more-relevant, quicker and cheaper first-in-human (FIH) testing. These approaches also have considerable potential to limit the use of animals in human drug development. Recent years have witnessed progress in applications, methodology, operations, and drug development culture. Advances in applications saw an expansion in therapeutic areas, developmental scenarios and scientific objectives, in, for example, protein drug development and paediatric drug development. In the operational area, the increased sensitivity of Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS), expansion of the utility of Positron Emission Tomography (PET) imaging, and the introduction of Cavity Ring-Down Spectroscopy (CRDS), have led to the increased accessibility and utility of Phase 0 approaches, while reducing costs and exposure to radioactivity. PET has extended the application of microdosing, from its use as a predominant tool to record pharmacokinetics, to a method for recording target expression and target engagement, as well as cellular and tissue responses. Advances in methodology include adaptive Phase 0/Phase 1 designs, cassette and cocktail microdosing, and Intra-Target Microdosing (ITM), as well as novel modelling opportunities and simulations. Importantly, these methodologies increase the predictive power of extrapolation from microdose to therapeutic level exposures. However, possibly the most challenging domain in which progress has been made, is the culture of drug development. One of the main potential values of Phase 0 approaches is the opportunity to terminate development early, thus not only applying the principle of ‘kill-early-kill-cheap’ to enhance the efficiency of drug development, but also obviating the need for the full package of animal testing required for therapeutic level Phase 1 studies. Finally, we list developmental scenarios that utilised Phase 0 approaches in novel drug development.

More medicines for children: impact of the EU paediatric regulation

IntroductionThis paper focuses on the authorisation of new medicines, new indications and new pharmaceutical forms or strengths for use in children and also on the availability of paediatric information in the product information of centrally authorised medicinal products following the enforcement of the Paediatric Regulation on 26 January 2007.ObjectivesTo investigate whether the Paediatric Regulation has led to more medicines available for children in the European Union (EU) and if more information on paediatric use is now available in the product information of medicines authorised via the centralised procedure.Materials and methodsWe retrospectively analysed the centrally authorised medicinal products in the EU that had an approval for an initial marketing authorisation, a type II variation, or a line extension during the years 2004–2006 and 2012–2014. Medicinal products not subjected to the obligations of the Paediatric Regulation were excluded.ResultsIn 2004–2006, 20 new medicines and 10 new indications were centrally authorised for paediatric use compared with 26 new medicines and 37 new indications in 2012–2014. The number of medicines with a new pharmaceutical form or strength for use in children was eight in 2004–2006 and seven in 2012–2014. There was a huge increase in the number of products with changes of paediatric relevance in the summary of product characteristics in 2012–2014 compared with 2004–2006.ConclusionsThe entry into force of the Paediatric Regulation has had a positive impact on paediatric drug development with more medicines available for children in the EU and substantially more information available for clinicians on paediatric use in the product information.