Pediatric Efficacy Extrapolation in Drug Development Submitted to the US Food and Drug Administration 2015-2020

A review on the role of extrapolation as basis for paediatric marketing authorization applications of medicines in the EU

AIMS

For new medicines, drug companies obtain regulatory approval on the strategy to generate evidence in the paediatric population, which can be supported by extrapolation of evidence obtained in a reference population. This study investigated whether paediatric marketing authorization applications (PMAAs) supported by extrapolation based on exposure-matching were more successful-i.e. approval of the targeted paediatric population-and efficient-i.e. duration of the drug development-compared to PMAAs not supported by extrapolation.

METHODS

Data was extracted from completed paediatric investigation plans (PIPs), associated drug labels and public assessment reports published on the European Medicines Agency website. Assessment reports were evaluated to assess whether PMAAs were supported by extrapolation based on exposure-matching. Wilcoxon rank-sum tests were used to compare PMAAs supported and not supported by extrapolation based on exposure-matching for outcomes of interest.

RESULTS

Exposure-matching supported the benefit/risk assessment of 39.6% of the PMAAs. Targeted and approved minimum age of the paediatric population were comparable for PMAAs where extrapolation based on exposure-matching supported the benefit/risk assessment (2.0 vs. 2.0 years, P-value = .72), but not for PMAAs not supported by extrapolation (0.2 years vs. 0.5 years, P-value = .05). Completion of drug development was 5.4 years vs. 4.3 years (P = .04) in PMAAs supported by extrapolation based on exposure-matching compared to those not supported by extrapolation, respectively.

CONCLUSIONS

PMAAs supported by extrapolation based on exposure-matching succeeded more often in obtaining marketing approval in the targeted paediatric population than PMAAs not supported by exposure-matching, but were also less efficient.

Editorial: Placebo Response in Child and Adolescent Psychiatry: To Mitigate or to Harness?

Antipsychotics and α-2 agonists are evidence-based medications for Tourette's Disorder (TD). Tic severity, functional impairment, and risk-benefit trade-offs guide treatment planning.1 However, much like other clinical disorders in child and adolescent psychiatry, treatment that definitively improves symptoms without also causing untoward side effects remains an unmet clinical need. This editorial reviews a metanalytic synthesis of the TD literature that focused on the magnitude of the placebo response in pharmacological trials of TD to understand how clinically meaningful efficacy results in the extent literature are, particularly in the context of some recent trial failures.

Prescription drug use in Danish children and adolescents 2005-2023

Continuous monitoring of pediatric drug utilization is important for ensuring rational use and prioritizing research. This study provides an overview of pediatric prescription drug use among Danish children and adolescents from 2005-2023. Using Danish nationwide individual-level dispensing data, we identified all redeemed prescriptions for individuals < 18 years from January 2005-December 2023. We computed overall annual prevalence proportions of users and mean number of prescriptions per child. For all non-antibiotic drugs, we further determined the quantity of drug use measured in defined daily doses (DDDs) and stratified all analyses by age and Anatomical Therapeutic Chemical classification first and forth level. During the study period, the overall yearly prevalence of prescription drug use decreased due to reductions in antibiotic prescribing. When antibiotic prescriptions were disregarded, the prevalence of children with at least one prescription increased from 38% in 2005 to 42% in 2023, while the mean number of prescriptions and DDDs increased from 1.2 prescriptions per child and 51.2 million DDDs in 2005 to 1.5 prescriptions per child and 76.5 million DDDs in 2023. This increase was primarily driven by prescribing of central nervous system drugs to adolescents 12-17 years, with a substantial increase in centrally acting sympathomimetics and melatonin use. Overall pediatric drug prescribing is decreasing due to reduced antibiotic use. Non-antibiotic drug use is, however, rising, especially among adolescents and notably for psychotropic drugs. These findings underscore the importance of ongoing monitoring and call for further research into underlying causes and prescription practices for psychotropics.

Pediatric-Specific Drug Loss Issue in Japan: Comparison of Pediatric Development Status Between Japan and the United States

BACKGROUND

The lack of label information for the pediatric population has been a global issue, leading to the introduction of several countermeasures by major health authorities. Despite various efforts by Japanese health authorities, some drugs are approved only for adults in Japan, while the United States (US) label includes information on pediatric usage for the same drugs. This suggests a potential for pediatric-specific drug loss in Japan, where overall drug loss has recently become a major concern.

METHODS

In this study, we compared the pediatric usage status between Japan and the US, focusing on the indications approved in both countries.

RESULTS

Of the 404 indications, 70 (17.3%) and 102 (25.2%) included pediatric usage in Japan and the US, respectively. The proportion of indications, including pediatric usage, was significantly higher in the US than in Japan (χ2 test, p < 0.001). Multivariate analysis of indications for pediatric usage in the US demonstrated that simultaneous development with adults (odds ratio (OR), 24.9; 95% confidence interval (CI), 6.79-91.1) and Japan-first development (OR, 31.5; 95% CI, 2.59-384) were significantly affecting the inclusion of pediatric usage in Japan.

CONCLUSIONS

Our results suggest that there was pediatric-specific drug loss in Japan compared to that in the US. The multivariate analysis demonstrated that US-first development and non-simultaneous development had a negative impact on the inclusion of pediatric usage in Japan; however, pediatric assessment request was not a significant factor. Further frameworks to promote pediatric drug development should be introduced in Japan to address pediatric-specific drug loss issues.

Paediatric Drug Development in Japan: Current Status and Future Challenges

INTRODUCTION

Until around 2000, the number of medicinal products labelled for paediatric use was limited worldwide. Regulatory measures to promote paediatric drug development in the US and Europe and the establishment of an international guideline (ICH-E11) have led to an increase in the number of paediatric labels. In Japan, efforts have been made to promote the development of paediatric drugs. This study was aimed to examine whether these supportive efforts are successful in Japan.

METHODS

This study examined the number of new drugs approved for paediatric indications in Japan from 2006 to 2023, as well as the clinical data package, that is, characteristics of the approved paediatric drugs and paediatric clinical trials, and the percentage of extrapolation of adult data, in the most recent 9-year period.

RESULTS

The number of paediatric drug approvals showed an increasing trend between 2006 and 2023 with some fluctuations. The proportion of drugs indicated for paediatric patients to the total number of approved drugs was about 30% until 2022, but increased to 48% in 2023. During the period from 2015 to 2023, simultaneous development in adults and children accounted for 59% (159/269) of paediatric development, but the complete extrapolation of adult data to paediatric populations has not been widely utilized (11.2%, 30/269).

CONCLUSIONS

The number of paediatric drug approvals has shown an upward trend, suggesting that measures to promote the development of paediatric drugs may have been exerting a favourable effect in Japan. However, there is still a limited number of drugs that have additional indications for paediatric use. Appropriate development strategies, such as the extrapolation of adult data to paediatric populations, should be considered if scientifically justified.

Model-informed drug development in pediatric, pregnancy and geriatric drug development: States of the art and future

The challenges of drug development in pediatric, pregnant and geriatric populations are a worldwide concern shared by regulatory authorities, pharmaceutical companies, and healthcare professionals. Model-informed drug development (MIDD) can integrate and quantify real-world data of physiology, pharmacology, and disease processes by using modeling and simulation techniques to facilitate decision-making in drug development. In this article, we reviewed current MIDD policy updates, reflected on the integrity of physiological data used for MIDD and the effects of physiological changes on the drug PK, as well as summarized current MIDD strategies and applications, so as to present the state of the art of MIDD in pediatric, pregnant and geriatric populations. Some considerations are put forth for the future improvements of MIDD including refining regulatory considerations, improving the integrity of physiological data, applying the emerging technologies, and exploring the application of MIDD in new therapies like gene therapies for special populations.

Conducting Drug Treatment Trials in Children: Opportunities and Challenges

Children were often referred to as "therapeutic orphans" in the past due to different reasons such as ethical, regulatory, economic, scientific, etc., ones. They were exposed to avoidable risks while missing out on therapeutic advances. Pediatric patients have suffered from a lack of scientific and regulatory standards (e.g., proper drug testing, authorization of medicines for their use, etc.), although the pharmaceutical legislative framework, which ensures the high standards of safety, quality, and efficacy of medicinal products for use in adults, was developed primarily in response to past "drug disasters," mainly involving children. The adoption of pediatric regulatory initiatives first in the USA and then in Europe and other countries and regions has significantly changed the worldwide frameworks and permanently changed pediatric drug research and development. This article tries to give various perspectives with historical context, a review of the different challenges and opportunities as well as important stakeholders in pediatric drug development. The pediatric trial networks are probably the most important stakeholder that enables efficient patient recruitment, access to better resource utilization, and global collaboration of different stakeholders necessary for performing quality and well-designed clinical trials.

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.

Pediatric dosing for locally acting drugs in submissions to the U.S. Food and Drug Administration between 2002 and 2020

Deriving pediatric doses for locally acting drugs (LADs) presents a unique challenge because limited systemic exposure hinders commonly used approaches such as pharmacokinetic matching to adults. This study systematically evaluated drug development practices used for pediatric dose selection of LADs approved by the U.S. Food and Drug Administration from 2002 to 2020. The three study objectives were: (1) to determine the dose selection approach for the labeled pediatric dose, (2) to examine the studied pediatric dose(s), and (3) to evaluate the characteristics of the pediatric clinical programs used to support the labeled pediatric dose. A total of 187 pediatric submissions were characterized for the labeled and studied pediatric doses of LADs. The pediatric dose was predominantly labeled as a flat dose (91%) and at a single-dose level (67%) similar to adults. The majority (68.4%) of the submissions had the same labeled dose for pediatrics and adults. Independent pharmacodynamic/efficacy studies in pediatric patients commonly (64.2%) provided supportive evidence for the labeled pediatric dose. Inhalation, nasal, and injectable submissions had the highest number of clinical trials, lowest usage of an extrapolation of efficacy approach, and utilized diverse approaches in selecting the studied pediatric doses. This article highlights approaches for LAD dosing in pediatric patients and can be used to inform drug development of these products in the pediatric population.

Advances in pharmacokinetic-pharmacodynamic modelling for pediatric drug development: extrapolations and exposure-response analyses

INTRODUCTION

Pharmacokinetic (PK)-Pharmacodynamic (PD) and exposure-response (E-R) modeling are critical parts of pediatric drug development. By integrating available knowledge and supportive data to support the design of future studies and pediatric dose selection, these techniques increase the efficiency of pediatric drug development and lowers the risk of exposing pediatric study participants to suboptimal or unsafe dose regimens.

AREAS COVERED

The role of PK, PK-PD and E-R modeling within pediatric drug development and pediatric dose selection is discussed. These models allow investigation of the impact of age and bodyweight on PK and PD in children, despite the often sparse data on the pediatric population. Also discussed is how E-R analyses strengthen the evidence basis to support (full or partial) extrapolation of drug efficacy from adults to children, and between different pediatric age groups.

EXPERT OPINION

Accelerated pediatric drug development and optimized pediatric dosing guidelines are expected from three future developments: (1) Increased focus on E-R modeling of currently approved drugs in children resulting in (novel) E-R modeling techniques and best practices, (2) increased use of real-world data for E-R (3) increased implementation of available population PK and E-R information in pediatric drug dosing guidelines.