The Need for Pediatric Drug Development

Analysis of the first ten years of FDA's rare pediatric disease priority review voucher program: designations, diseases, and drug development

BACKGROUND

The Rare Pediatric Disease (RPD) Priority Review Voucher (PRV) Program was enacted in 2012 to support the development of new products for children. Prior to requesting a voucher, applicants can request RPD designation, which confirms their product treats or prevents a rare disease in which the serious manifestations primarily affect children. This study describes the trends and characteristics of these designations. Details of RPD designations are not publicly disclosable; this research represents the first analysis of the RPD designation component of the program.

RESULTS

We used an internal US Food and Drug Administration database to analyze all RPD designations between 2013 and 2022. Multiple characteristics were analyzed, including the diseases targeted by RPD designation, whether the product targeted a neonatal disease, product type (drug/biologic), and the level of evidence (preclinical/clinical) to support designation. There were 569 RPD designations during the study period. The top therapeutic areas were neurology (26%, n = 149), metabolism (23%, n = 131), oncology (18%, n = 105). The top diseases targeted by RPD designation were Duchenne muscular dystrophy, neuroblastoma, and sickle cell disease. Neonatology products represented 6% (n = 33), over half were for drug products and 38% were supported by clinical data.

CONCLUSIONS

The RPD PRV program was created to encourage development of new products for children. The results of this study establish that a wide range of diseases have seen development-from rare pediatric cancers to rare genetic disorders. Continued support of product development for children with rare diseases is needed to find treatments for all children with unmet needs.

Orphan Drug Label Expansions: Analysis Of Subsequent Rare And Common Indication Approvals

The Orphan Drug Act of 1983 was enacted to provide financial incentives to stimulate drug development for rare diseases. In recent years, concerns have been raised regarding these orphan drugs, including how many are being approved for both rare and common diseases and the number of subsequent indication approvals. Policy makers have suggested modifications to the Orphan Drug Act's incentives to address these concerns. In this study we investigated the approval "family trees" of orphan drugs. We found that 491 novel orphan drugs were approved between 1990 and 2022. To date, 65 percent have been approved for a single rare disease, 15 percent have been approved for multiple rare diseases, and 20 percent have been approved for both rare and common diseases. Ten percent of orphan drugs received a subsequent indication approval for a pediatric population of an orphan disease. Revenue estimates from 2021 show that one-third of the drugs approved for both rare and common indications and 6 percent of rare-only drugs were among the 200 top-selling drugs worldwide. The results have implications for the possible externalities of modifying the incentives of the Orphan Drug Act, such as a potential decrease in the initiation of programs to develop pediatric rare disease drugs.

Off-Label Prescribing in Pediatric Population-Literature Review for 2012-2022

Off-label prescribing is widespread among pediatricians, and it is unlikely that this trend will soon be bound by a uniform legal framework. This is necessitated by the fact that there are four variables: the patient's health condition, the physician's experience and knowledge, the legislative measures (laws, directives, guidelines, and recommendations), and finally, the pharmaceutical industry. There is considerable concern worldwide about the use of off-label medicines in children. We may call it an enormous global problem that is much talked about and written about; however, we should not forget that the goal around which everyone should unite is the patient's life. For healthcare providers, the most important thing will always be the health and preservation of the patient's life, particularly when it comes to children with life-threatening conditions in neonatal and pediatric intensive care units (NICU and PICU). The study aimed to examine the prevalence of off-label drug use in pediatrics. Literature research was conducted, and we included studies from 2012 to 2022 that evaluated off-label drug prevalence in various pediatric patient populations.

Real world data (RWD) in pediatrics

Unique challenges pertain when studying children, although many research principles are the same as those when studying adult populations. This truism extends to the use of real-world data (RWD). RWD are particularly relevant to pediatrics because they may potentially provide an additional source of data to inform pediatric labeling and practice patterns when clinical trials have not been or cannot be conducted. The purpose of this commentary is to provide a brief overview of the unique issues in using RWD to study the effectiveness or safety of medical therapies in children.

Diagnostic challenge: A pediatric patient with severe obesity and complications of imminent death

Background

A 15-year-old patient suffering from severe obesity (400 pounds, BMI 71.6 kg/m2) with a clinical phenotype suggestive of syndromic obesity was hospitalized for severe heart failure and cardiogenic shock. The hospital admission prompted a palliative care and heart transplant consultation given end-stage-disease and poor prognosis. It further necessitated a pediatric inpatient obesity consult, which was complicated by several significant hurdles including lack of insurance coverage, FDA approvals, availability of medications, and inadequate knowledge among the medical community.

Methods

Innovative treatment, proactive, persistent advocacy, anti-obesity medication combination strategies modeled after diabetes and hypertension treatment algorithms, and latest evidence in obesity management were utilized to effectively and expeditiously overcome major challenges to care and the medical emergency.

Results

The patient was stabilized and ultimately discharged home, after -25.2% weight loss over 4 months (weight down to 299 pounds, BMI 49.9 kg/m2) through collaborative medical obesity intervention.

Conclusion

The typical delay in care sought by patients suffering from obesity, often due to stigma and lack of disease awareness, results in missed opportunities to prevent serious obesity-related complications. Skilled specialist expertise, fund of obesity-specific knowledge, and constant advocacy can be crucial in surmounting regulatory barriers to obesity care and in generating successful weight loss outcomes.

Purification processes of polymeric nanoparticles: How to improve their clinical translation?

Polymeric nanoparticles, as revolutionary nanomedicines, have offered a new class of diagnostic and therapeutic solutions for a multitude of diseases. With its immense potential, the world witnesses the new age of nanotechnology after the COVID-19 vaccines were developed based on nanotechnology. Even though there are countless benchtop research studies in the nanotechnology world, their integration into commercially available technologies is still restricted. The post-pandemic world demands a surge of research in the domain, which leaves us with the fundamental question: why is the clinical translation of therapeutic nanoparticles so restricted? Complications in nanomedicine purification, among other things, are to blame for the lack of transference. Polymeric nanoparticles, owing to their ease of manufacture, biocompatibility, and enhanced efficiency, are one of the more explored domains in organic-based nanomedicines. Purification of nanoparticles can be challenging and necessitates tailoring the available methods in accordance with the polymeric nanoparticle and impurities involved. Though a number of techniques have been described, there are no available guidelines that help in selecting the method to better suit our requirements. We encountered this difficulty while compiling articles for this review and looking for methods to purify polymeric nanoparticles. The currently accessible bibliography for purification techniques only provides approaches for a specific type of nanomaterial or sometimes even procedures for bulk materials, that are not fully relevant to nanoparticles. In our research, we tried to summarize the available purification techniques using the approach of A.F. Armington. We divided the purification systems into two major classes, namely: phase separation-based techniques (based on the physical differences between the phases) and matter exchange-based techniques (centered on physicochemical induced transfer of materials and compounds). The phase separation methods are based on either using nanoparticle size differences to retain them on a physical barrier (filtration techniques) or using their densities to segregate them (centrifugation techniques). The matter exchange separation methods rely on either transferring the molecules or impurities across a barrier using simple physicochemical phenomena, like the concentration gradients (dialysis method) or partition coefficients (extraction technique). After describing the methods in detail, we highlight their advantages and limitations, mainly focusing on preformed polymer-based nanoparticles. Tailoring a purification strategy takes into account the nanoparticle structure and its integrity, the method selected should be suited for preserving the integrity of the particles, in addition to conforming to the economical, material and productivity considerations. In the meantime, we advocate the use of a harmonized international regulatory framework to define the adequate physicochemical and biological characterization of nanomedicines. An appropriate purification strategy serves as the backbone to achieving desired characteristics, in addition to reducing variability. As a result, the present review aspires to serve as a comprehensive guide for researchers, who are new to the domain, as well as a synopsis of purification strategies and analytical characterization methods used in preclinical studies.

Status of pediatric echocardiography clinical trials: a cross-sectional study of registered trials in ClinicalTrials.gov

Background

The objective of this study is to analyze the characteristics of pediatric echocardiography clinical trials registered in ClinicalTrials.gov.

Methods

A data set including pediatric echocardiography clinical trials was downloaded from ClinicalTrials.gov until May 13, 2022. We searched the PubMed, Medline, Google Scholar, and Embase databases to extract publication data. Pediatric echocardiography trial characteristics, application areas, and publication status were described. The secondary objectives were to evaluate factors associated with trial publication.

Results

We identified 410 pediatric echocardiography reporting definite age, of which 246 were interventional and 146 were observational. Drug interventions were the most commonly studied (32.9%). The most applied area of pediatric echocardiography was congenital heart disease, followed by hemodynamics of preterm or neonatal infants, cardiomyopathy, inflammatory heart disease, pulmonary hypertension, and cardio-oncology. According to the primary completion data, 54.9% of the trials were completed before August 2020. 34.2% of the trials had been published within 24 months. Union countries and quadruple masking were more likely to be published.

Conclusion

Echocardiography is rapidly evolving in pediatric clinical applications, including anatomic imaging and functional imaging. Novel speckle tracking techniques have also been pivotal in the assessment of cancer therapeutics-related cardiac dysfunction. A small number of clinical trials in pediatric echocardiography are published in a timely fashion. Concerted efforts are needed to promote trial transparency.

Complex and alternate consent pathways in clinical trials: methodological and ethical challenges encountered by underserved groups and a call to action

BACKGROUND

Informed consent is considered a fundamental requirement for participation in trials, yet obtaining consent is challenging in a number of populations and settings. This may be due to participants having communication or other disabilities, their capacity to consent fluctuates or they lack capacity, or in emergency situations where their medical condition or the urgent nature of the treatment precludes seeking consent from either the participant or a representative. These challenges, and the subsequent complexity of designing and conducting trials where alternative consent pathways are required, contribute to these populations being underserved in research. Recognising and addressing these challenges is essential to support trials involving these populations and ensure that they have an equitable opportunity to participate in, and benefit from, research. Given the complex nature of these challenges, which are encountered by both adults and children, a cross-disciplinary approach is required.

DISCUSSION

A UK-wide collaboration, a sub-group of the Trial Conduct Working Group in the MRC-NIHR Trial Methodology Research Partnership, was formed to collectively address these challenges. Members are drawn from disciplines including bioethics, qualitative research, trials methodology, healthcare professions, and social sciences. This commentary draws on our collective expertise to identify key populations where particular methodological and ethical challenges around consent are encountered, articulate the specific issues arising in each population, summarise ongoing and completed research, and identify targets for future research. Key populations include people with communication or other disabilities, people whose capacity to consent fluctuates, adults who lack the capacity to consent, and adults and children in emergency and urgent care settings. Work is ongoing by the sub-group to create a database of resources, to update NIHR guidance, and to develop proposals to address identified research gaps.

CONCLUSION

Collaboration across disciplines, sectors, organisations, and countries is essential if the ethical and methodological challenges surrounding trials involving complex and alternate consent pathways are to be addressed. Explicating these challenges, sharing resources, and identifying gaps for future research is an essential first step. We hope that doing so will serve as a call to action for others seeking ways to address the current consent-based exclusion of underserved populations from trials.

Technical, Ethical, Legal, and Societal Challenges With Digital Twin Systems for the Management of Chronic Diseases in Children and Young People

Advances in digital medicine now make it possible to use digital twin systems (DTS), which combine (1) extensive patient monitoring through the use of multiple sensors and (2) personalized adaptation of patient care through the use of software. After the artificial pancreas system already operational in children with type 1 diabetes, new DTS could be developed for real-time monitoring and management of children with chronic diseases. Just as providing care for children is a specific discipline—pediatrics—because of their particular characteristics and needs, providing digital care for children also presents particular challenges. This article reviews the technical challenges, mainly related to the problem of data collection in children; the ethical challenges, including the need to preserve the child's place in their care when using DTS; the legal challenges and the dual need to guarantee the safety of DTS for children and to ensure their access to DTS; and the societal challenges, including the needs to maintain human contact and trust between the child and the pediatrician and to limit DTS to specific uses to avoid contributing to a surveillance society and, at another level, to climate change. 

Prescribing Patterns of Amantadine During Pediatric Inpatient Rehabilitation After Traumatic Brain Injury: A Multicentered Retrospective Review From the Pediatric Brain Injury Consortium

OBJECTIVES

To describe dosing practices for amantadine hydrochloride and related adverse effects among children and young adults with traumatic brain injury (TBI) admitted to pediatric inpatient rehabilitation units.

SETTING

Eight pediatric acute inpatient rehabilitation units located throughout the United States comprising the Pediatric Brain Injury Consortium.

PARTICIPANTS

Two-hundred thirty-four children and young adults aged 2 months to 21 years with TBI.

DESIGN

Retrospective data revie.

MAIN OUTCOME MEASURES

Demographic variables associated with the use of amantadine, amantadine dose, and reported adverse effects.

RESULTS

Forty-nine patients (21%) aged 0.9 to 20 years received amantadine during inpatient rehabilitation. Forty-five percent of patients admitted to inpatient rehabilitation with a disorder of consciousness (DoC) were treated with amantadine, while 14% of children admitted with higher levels of functioning received amantadine. Children with DoC who were not treated with amantadine were younger than those with DoC who received amantadine (median 3.0 vs 11.6 years, P = .008). Recorded doses of amantadine ranged from 0.7 to 13.5 mg/kg/d; the highest total daily dose was 400 mg/d. Adverse effects were reported in 8 patients (16%); nausea/abdominal discomfort and agitation were most common, each reported in 3 patients. The highest reported dose without an adverse effect was 10.1 mg/kg/d.

CONCLUSION

During pediatric inpatient rehabilitation, amantadine was prescribed to children across a range of ages and injury severity and was most commonly prescribed to older children with DoC. Dosing varied widely, with weight-based dosing for younger/smaller children at both lower and higher doses than what had been previously reported. Prospective studies are needed to characterize the safety and tolerability of higher amantadine doses and optimize amantadine dosing parameters for children with TBI.

Accelerating the Availability of Medications to Pediatric Patients by Optimizing the Use of Extrapolation of Efficacy

Improving pediatric therapeutic development is a mission of universal importance among health authorities, pharmaceutical companies, academic institutions, and healthcare professionals. Following the passage of legislation in the United States and Europe, we witnessed the most significant advancement yet in pediatric data generation, resulting in added pediatric use information to almost 700 product labels. Tools to accelerate generation of data for the pediatric population are available for use today, and when utilized in accordance with current practices and laws, these tools could increase the amount and timeliness of pediatric information available for clinicians and patients. If we utilize the current laws that allow regulators to incentivize and require evidence generation, apply extrapolation, and utilize modeling and simulation, as well as including adolescents in the pivotal studies alongside adults as appropriate, two strategic goals could be achieved by 2030: (1) reduce the time to pediatric approval by 50%, and (2) renew pediatric labeling information for 15 priority pediatric drugs without patent and/or exclusivity.

Current situation of pediatric clinical trials in China: focus on trials for drug marketing application and administrative approval

Background

Research and development of pediatric drug faces many difficulties and pediatric clinical trials remain a challenge. Since 2011, a series of measures have been taken to encourage research, development of drugs for pediatric patients in China. In this study, we analyzed pediatric clinical trials conducted in China to provide reference for research and development of pediatric drugs and formulation of relevant policies.

Methods

We conducted a cross-sectional observational study of pediatric trials registered in the Drug Trial Registration and Information Publication Platform before Oct. 31, 2021. All trials that recruited children (under 18 years old as defined in China) were retrieved and general characteristics of the trials and the research drugs were extracted and analyzed. The data were extracted and statistically analyzed by excel 2010 and SPSS 22.0, respectively.

Results

There were 588 registered pediatric clinical trials, which accounted for 3.94% of the total registered trials. The overall average annual growth rate of the number of trials from 2013 to 2020 was 14.47% (P < 0.01). Of the 588 trials included, there were 312 trials (53.06%) with only children as subjects, 127 trials (21.60%) with research drugs only for children use, and the median of target subject number was 320 with the range of 8 to 600,000. The sponsors and the principal investigators were mainly located in the eastern and northern China. 325 trials were vaccine trials, and the dosage form was mainly injection. There were 98 non-vaccine biological product trials (mainly injections), 135 chemical compound drug trials (mainly tablets), 30 traditional Chinese medicine/natural drugs (mainly granules). Indications of the non-vaccine drugs were mainly diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism.

Conclusion

The number of pediatric clinical trials in China has increased these years. To further promote pediatric clinical trials and motivate pediatric appropriate drug marketing application and administrative approval, conducting large pediatric clinical trials, further development of dosage forms suitable for children with special attention to neonates and prematurity, and improving uneven geographical distribution of sponsors and researchers are the current challenges.

Neurology's vital role in preventing unnecessary and potentially harmful pediatric studies

INTRODUCTION

Regulatory authorities recognize two human populations: adults and children defined as <18 years. For drug approval, they demand separate studies. But humans mature slowly during puberty. The 18^th birthday is an administrative limit that does not correspond to a physiological change. Separate drug approval before/after the 18^th birthday reflects the children-are-therapeutic-orphans concept that emerged after 1962. The Food and Drug Administration (FDA) has backed away from this concept for antiepileptic drugs, but sticks to it in other areas. In contrast, the European Medicines Agency (EMA) is continuously expanding its demand for "pediatric" studies. Parents hesitate increasingly to let their children participate in questionable studies.

AREAS COVERED

Neurologists challenge the children-are-therapeutic-orphans mantra. Young patients do not need separate proof of efficacy & safety, but appropriate dosing recommendations. Minors should be treated as human beings, instead of being abused in questionable studies.

EXPERT OPINION

Young patients with multiple sclerosis and other neurological diseases deserve studies with therapeutic intentions. "Pediatric" careers have emerged in academia, regulatory authorities, and pharmaceutical companies. Institutional Review Boards/ Ethics Committees should suspend questionable "pediatric" studies and reject newly submitted ones. The medical professions should distance themselves from questionable "pediatric" research that reflects massive conflicts of interest.

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.

Opportunities and Challenges in Developing a Cryptosporidium Controlled Human Infection Model for Testing Antiparasitic Agents

Cryptosporidiosis is a leading cause of moderate-to-severe diarrhea in low- and middle-income countries, responsible for high mortality in children younger than two years of age, and it is also strongly associated with childhood malnutrition and growth stunting. There is no vaccine for cryptosporidiosis and existing therapeutic options are suboptimal to prevent morbidity and mortality in young children. Recently, novel therapeutic agents have been discovered through high-throughput phenotypic and target-based screening strategies, repurposing malaria hits, etc., and these agents have a promising preclinical in vitro and in vivo anti-Cryptosporidium efficacy. One key step in bringing safe and effective new therapies to young vulnerable children is the establishment of some prospect of direct benefit before initiating pediatric clinical studies. A Cryptosporidium controlled human infection model (CHIM) in healthy adult volunteers can be a robust clinical proof of concept model for evaluating novel therapeutics. CHIM could potentially accelerate the development path to pediatric studies by establishing the safety of a proposed pediatric dosing regimen and documenting preliminary efficacy in adults. We present, here, perspectives regarding the opportunities and perceived challenges with the Cryptosporidium human challenge model.

COVID-19 and Treatment and Immunization of Children-The Time to Redefine Pediatric Age Groups is Here

Children are infected with coronavirus disease 2019 (COVID-19) as often as adults, but with fewer symptoms. During the first wave of the COVID-19 pandemic, multisystem inflammatory syndrome (MIS) in children (MIS-C), with symptoms similar to Kawasaki syndrome, was described in young minors testing positive for COVID-19. The United States (US) Centers for Disease Control and Prevention (CDC) defined MIS-C as occurring in <21-year-olds, triggering hundreds of PubMed-listed papers. However, postpubertal adolescents are no longer children biologically; the term MIS-C is misleading. Furthermore, MIS also occurs in adults, termed MIS-A by the CDC. Acute and delayed inflammations can be triggered by COVID-19. The 18th birthday is an administrative not a biological age limit, whereas the body matures slowly during puberty. This blur in defining children leads to confusion regarding MIS-C/MIS-A. United States and European Union (EU) drug approval is handled separately for children, defined as <18-year-olds, ascribing non-existent physical characteristics up to the 18th birthday. This blur between the administrative and the physiological meanings for the term child is causing flawed demands for pediatric studies in all drugs and vaccines, including those against COVID-19. Effective treatment of all conditions, including COVID-19, should be based on actual physiological need. Now, the flawed definition for children in the development of drugs and vaccines and their approval is negatively impacting prevention and treatment of COVID-19 in minors. This review reveals the necessity for redefining pediatric age groups to rapidly establish recommendations for optimal prevention and treatment in minors.

Paediatric Medicines - Regulatory Drivers, Restraints, Opportunities and Challenges

The investment in the pharmaceutical development of medicines for paediatric use represents a minority when compared to that one made for adult population. Which reasons lie behind this status quo? Which policies have been implemented to reverse such asymmetry? Is there room to new regulatory initiatives? The creation of regulations establishing the obligation to conduct paediatric trials was deemed necessary as a means of producing products of proven quality, safety and efficacy and, in addition, to set forth financial incentives for the pharmaceutical industry reduce this delay. The first regulatory initiatives were carried out by the Food and Drug Administration (FDA) at the end of the 20^th century. Later on, the European Medicines Agency (EMA) issued the Paediatric Regulation, which has boosted a closer collaboration between both regulatory agencies. Along with the implemented legislation, pharmaceutical dosage forms, more adapted to the paediatric population have emerged, increasing the availability of age-appropriate formulations. However, a case-by-case analysis is required to ensure the best therapeutic option for the specific child. This review aims at discussing the development of medicines for paediatric use from a regulatory perspective, comparing the policies adopted by the EMA and FDA, following an overview of the drivers, restraints, opportunities and challenges.

The Utility of Pharmacometric Models in Clinical Pharmacology Research in Infants

Purpose of commentary

Acquiring knowledge on drug disposition and action in infant is challenging because of the problem of sparse and unbalanced data obtained for each individual infant due to the limited blood volume as well as the issue of extensive inter-subject and intra-subject variability in drug exposure and response due to the fast growth and dynamic maturation changes in infants. This commentary highlights the importance of using population-based pharmacometric models to improve knowledge on drug disposition and action in infants.

Recent findings

Pharmacometric modeling remains to be critical in clinical pharmacology research in infants. Many pediatric covariate models developed for scaling of drug clearance use a combination of allometric weight scaling to account for size change and a sigmoid function of antenatal development and postnatal maturation to characterize the age-related maturation. To expedite the development of safe and effective dosing regimens in infants, a number of strategies have been proposed recently, including the use of pediatric covariate model obtained from one drug for extrapolation to other drugs undergoing similar elimination pathways, as well as the combination of opportunistic clinical studies and population-based pharmacometrics models.

Summary

Population-based pharmacometric modeling plays a pivotal role in clinical pharmacology research in infants. Most of the covariate models reported so far focus on antibiotics undergoing renal elimination. Novel modeling strategies have been proposed recently to facilitate clinical pharmacology research and expedite the dose optimization process in infants.

Orphan Formulations for Pediatric Use: Development and Stability Control of Two Sildenafil Citrate Solutions for the Treatment of Pulmonary Hypertension

Sildenafil citrate causes vasodilatation, relaxation of the smooth muscle, and reduction of pulmonary arterial pressure. The latter property makes sildenafil citrate efficient for the treatment of cardiovascular diseases, including pulmonary arterial hypertension. Pediatric patients with pulmonary arterial hypertension are more susceptible to errors in drug administration than adults because of a lack of suitable drug dosages. Thus, the purpose of this study was to develop stable (chemically and microbiologically) sildenafil citrate drop liquid formulation, suitable for pediatric patients (including diabetics), ensuring safety during preparation and storing and improving palatability by using milk as a carrier for administration. The significant factors that affect the sildenafil solubility were evaluated by applying a Plackett-Burman design using two levels with six variables. The experiment showed that the type of buffer and glycerin content influenced the sildenafil solubility. The developed formulations proved to be stable for 6 months at all three assayed conditions (40± 2°C, 75 ± 5% RH; 25± 2°C, 60 ± 5% RH; and 4 ± 2°C). The microbiological tests fit with the requirement of the pharmacopeia at day 0 and 90 and even more at day 180. Finally, the palatability assay showed that 0.82 mL of the formulation containing buffer phosphate, 20% glycerin, and 4 mg mL^-1 of sildenafil citrate diluted in 4.8 mL milk (which fits the medium pediatric dose) presented similar palatability to milk alone, and no precipitate or turbidity was observed. Graphical abstract.

Ethical Issues in Pediatric Regulatory Studies Involving Placebo Treatment

Separate pediatric studies for antiepileptic drugs (AEDs) emerged with general separate drug approval in children and were defined by the U.S. Food and Drug Administration (FDA) as <17 years and by the European Union (EU) as <18 years. These administrative age limits are necessary in pediatrics, but they correspond variably with the physiological maturity of young patients and are not helpful for therapeutic decisions or as study inclusion criteria. AEDs are often effective for partial onset seizures (POS) in 2 to 17-year-olds as well as in ≥18-year-olds, if dosed correctly. Separate pediatric AED studies assume no difference between the legal and the physiological meaning of the word “child.” While the FDA now accepts efficacy of AEDs in POS in children ≥2 years, the EU still requires separate “pediatric” studies. For retigabine it waived all pediatric studies after having required 20 such studies over several years. We feel the current regulation creates a situation where many studies in children are done unnecessarily; we question the ethics of such an approach, which in our view, is morally wrong. Critical publications contributed to the FDA's shift of opinion for AEDs in POS but did not address the blur of different meanings of the word “child.”

Too Many Avoidable Suicides Occur Worldwide in Young Patients

United States (US) and European Union (EU) laws attempt to counterbalance the presumed discrimination of children in drug treatment and drug development. The US Food and Drug Administration (FDA)-rewarded pediatric studies with antidepressants triggered in 2004 an FDA black-box warning of suicidality in young patients. Fewer antidepressants were prescribed, and the number of completed suicides of young persons increased. The dilemma between this warning and the need to adequately treat young depressed patients remains unsolved. We analyzed the history of drug development, the evolving view of diseases in young patients, US/EU pediatric laws, and pediatric studies triggered by FDA/European Medicines Agency (EMA) in depression and other diseases on the background of developmental pharmacology; financial, institutional, and other interests; and the literature. The FDA/EMA define children administratively, not physiologically, as <17 (FDA)/<18 years old (EMA). But young persons mature physiologically well before their 17th/18th birthday. Depression occurs in young persons, has special characteristics, but is not fundamentally different from adult depression. Young persons are not another species. Regulatory requirements for "pediatric" studies focus on "pediatric" labels. Many "pediatric" studies, including those in depression, lacked and lack medical sense and harm patients by placebo treatment although effective drugs exist. The FDA has partially abandoned separate "pediatric" efficacy studies, but not in psychiatry. Clinicians, parents, institutional review boards, and ethics committees should become aware of questionable "pediatric" studies, should re-evaluate ongoing ones, consider to suspend them, and to reject new ones. The concept of separate "pediatric" drug approval needs to be abandoned.

Enhancing Clinical Data and Clinical Research Data with Biomedical Ontologies - Insights from the Knowledge Representation Perspective

Objectives : There exists a communication gap between the biomedical informatics community on one side and the computer science/artificial intelligence community on the other side regarding the meaning of the terms “semantic integration" and “knowledge representation“. This gap leads to approaches that attempt to provide one-to-one mappings between data elements and biomedical ontologies. Our aim is to clarify the representational differences between traditional data management and semantic-web-based data management by providing use cases of clinical data and clinical research data re-representation. We discuss how and why one-to-one mappings limit the advantages of using Semantic Web Technologies (SWTs).

Methods : We employ commonly used SWTs, such as Resource Description Framework (RDF) and Ontology Web Language (OWL). We reuse pre-existing ontologies and ensure shared ontological commitment by selecting ontologies from a framework that fosters community-driven collaborative ontology development for biomedicine following the same set of principles.

Results : We demonstrate the results of providing SWT-compliant re-representation of data elements from two independent projects managing clinical data and clinical research data. Our results show how one-to-one mappings would hinder the exploitation of the advantages provided by using SWT.

Conclusions : We conclude that SWT-compliant re-representation is an indispensable step, if using the full potential of SWT is the goal. Rather than providing one-to-one mappings, developers should provide documentation that links data elements to graph structures to specify the re-representation.

Rational Use of Medicine in Children-The Conflict of Interests Story. A Review

BACKGROUND

United States (US) and European Union (EU) legislation attempts to counterbalance the presumed discrimination in pediatric drug treatment and development.

METHODS

We analyzed the history of drug development, US/EU pediatric laws, and pediatric studies required by US/EU regulatory authorities and reviewed relevant literature.

RESULTS

The US and EU definitions of a child are defined administratively (rather than physiologically) as being aged <17 years and <18 years, respectively. However, children mature physiologically well before their seventeenth or eighteenth birthdays. The semantic blur for these differing definitions may indicate certain conflicts of interest.

CONCLUSIONS

Pediatric healthcare today is better than ever. Regulatory-related requirements for "pediatric" studies focus on labeling. Most of these studies lack medical usefulness and may even harm "pediatric" patients through administration of placebo and/or substandard treatment, despite the resultant publications, networking, patent extensions, and strengthened regulatory standing. Clinicians, parents, and ethics committees should be aware of these issues. New rules are needed to determine new pharmaceutical dose estimates in prepubescent patients, and when/how to clinically confirm them. Internet-based structures to divulge this information should be established between drug developers, clinicians, and regulatory authorities. A prerequisite for the rational use of pharmaceuticals in children would be to correct the flawed concept that children are discriminated against in drug treatment and development, and to abandon separate "pediatric" drug approval processes.

The Pediatric Cell Atlas: Defining the Growth Phase of Human Development at Single-Cell Resolution

Single-cell gene expression analyses of mammalian tissues have uncovered profound stage-specific molecular regulatory phenomena that have changed the understanding of unique cell types and signaling pathways critical for lineage determination, morphogenesis, and growth. We discuss here the case for a Pediatric Cell Atlas as part of the Human Cell Atlas consortium to provide single-cell profiles and spatial characterization of gene expression across human tissues and organs. Such data will complement adult and developmentally focused HCA projects to provide a rich cytogenomic framework for understanding not only pediatric health and disease but also environmental and genetic impacts across the human lifespan.

Globalization of pediatric research: pharmacological RCTs in Latin America

Globalization caused a shift in trial locations towards low-middle income countries, raising ethical concerns. These include the risk that conditions primarily affecting children in these countries will be neglected in favor of those affecting developed countries. We analyzed 253 published and 69 ongoing pharmacological RCTs performed in Latin America between 2000 and 2015 involving exclusively children. While over 50% of the previously highly investigated diseases were no longer priorities, other diseases acquired greater attention in recent years. Brazil and Mexico resulted as the most active countries. A large gap remains between the real needs of children in these countries and scientific research.

The Challenges of Pediatric Drug Development

INTRODUCTION AND BACKGROUND

"Pediatric Drug Development" is being used to describe not the development of drugs for children, but rather the planning & conducting separate efficacy and safety (E&S) studies requested/demanded by regulatory authorities designed to produce pediatric labels. Pediatric studies required for drug approval enroll "children"; defined as <17 years of age (US Food and Drug Administration [FDA])/ <18 years (European Union [EU]). The medical rationale for study designs was examined.

MATERIAL & METHODS

International industry-sponsored pediatric E&S studies registered in www.clinicaltrials.gov were analysed along with the history of US/EU laws, published literature, internet-retrieved regulatory documents, and regulatory/ American Academy of Pediatrics (AAP) justifications for doing separate pediatric E&S studies.

RESULTS

US/EU regulators utilize an official, but non-physiological definition of childhood based on an age limit of 17/18 years. This definition, which blurs the interface between medicine and law, emerged after clinical studies became required for drug approval in 1962 prompting drug manufacturers to insert pediatric warnings into product information. Intended largely as legal protection against liability, they were interpreted medically. Absorption, distribution, metabolism, excretion mature rapidly. Drug toxicities seen in newborns during the first months of life were cited by AAP/FDA in warnings of dangers of drugs in all "children" including in adolescents who are physiologically no longer children. Warnings were/are exaggerated, exploit/ed parents' protective instincts and fears, and increase/d pediatric clinical trial activity. Conflicts of interest created by this increased activity involve research funding, career status & advancement, commercial profits.

DISCUSSION

FDA/EMA-requested/demanded "pediatric" studies were identified which lack medical sense at best, others actually harm young patients by impeding use of superior, effective treatments. Separate labels for different indications make medical sense; separate approval in persons above/below 17/18 years of age does not.

CONCLUSIONS

Pediatric medical research should be restricted to studies which meet important medical needs of all recruited young patients, which generate information that cannot be obtained by other study designs, and do not limit access to superior alternative therapies. Clinical centers, investigators, and IRBs/ECs should more carefully examine studies for unjustified regulatory demands, prevention of subjects' access to superior treatments, and undeclared COI's. Questionable studies should not be approved and ongoing ones should be suspended.

Twenty years of progress in paediatric psychopharmacology: accomplishments and unmet needs

The systematic assessment of the efficacy and safety of psychiatric medications in children and adolescents started about 20 years ago. Since then, a considerable number of randomised clinical trials have been conducted, including also a series of publicly funded comparative effectiveness studies to evaluate the therapeutic benefit of medications relative to psychosocial interventions, alone or combined with medications. On the whole, these studies have been informative of the paediatric pharmacokinetics, efficacy and safety of the most commonly used psychotropics. As a consequence, a number of meta-analyses have been conducted that have documented both the benefits and harms of the most common medication groups, such as stimulants, antidepressants and antipsychotics. Evidence-based practice guidelines have been produced, and clinicians can now better estimate the therapeutic value and the risk of treatment, at least at the group mean level. However, most clinical trials have been conducted in research settings, and this limits the generalisability of the results. There is a need for evaluating treatment effects under usual practice conditions, through practical trials. The ongoing debate about the proper role of pharmacotherapy in child mental health can be advanced by comparative effectiveness research to assess the benefit/risk ratio of pharmacotherapy vis-à-vis alternative treatment modalities. In addition, analyses of large population databases can better inform on the impact of early treatment on important distal outcomes, such as interpersonal functioning, social and occupational status, quality of life and risk for disability or mortality. Thus far, paediatric psychopharmacology has been mostly the application to children of medications that were serendipitously discovered and developed for adults. By focusing on the neurobiological mechanisms of child psychopathology, it may be possible to identify more precise pharmacological targets and arrive at a truly developmental psychopharmacology.

Barriers to Drug Distribution into the Perinatal and Postnatal Brain

Drug bioavailability to the developing brain is a major concern in the treatment of neonates and infants as well as pregnant and breast-feeding women. Central adverse drug reactions can have dramatic consequences for brain development, leading to major neurological impairment. Factors setting the cerebral bioavailability of drugs include protein-unbound drug concentration in plasma, local cerebral blood flow, permeability across blood-brain interfaces, binding to neural cells, volume of cerebral fluid compartments, and cerebrospinal fluid secretion rate. Most of these factors change during development, which will affect cerebral drug concentrations. Regarding the impact of blood-brain interfaces, the blood-brain barrier located at the cerebral endothelium and the blood-cerebrospinal fluid barrier located at the choroid plexus epithelium both display a tight phenotype early on in embryos. However, the developmental regulation of some multispecific efflux transporters that also limit the entry of numerous drugs into the brain through barrier cells is expected to favor drug penetration in the neonatal brain. Finally, drug cerebral bioavailability is likely to be affected following perinatal injuries that alter blood-brain interface properties. A thorough investigation of these mechanisms is mandatory for a better risk assessment of drug treatments in pregnant or breast-feeding women, and in neonate and pediatric patients.