Different treatment benefits were estimated by clinical trials performed in adults compared with those performed in children

Dose rationale for gabapentin and tramadol in pediatric patients with chronic pain

Despite off-label use, the efficacy and safety of gabapentin and tramadol in pediatric patients (3 months to <18 years old) diagnosed with chronic pain has not been characterized. However, generating evidence based on randomized clinical trials in this population has been extremely challenging. The current investigation illustrates the use of clinical trial simulations (CTSs) as a tool for optimizing doses and protocol design for a prospective investigation in pediatric patients with chronic pain. Pharmacokinetic (PK) modeling and CTSs were used to describe the PKs of gabapentin and tramadol in the target population. In the absence of biomarkers of analgesia, systemic exposure (AUC, Css) was used to guide dose selection under the assumption of a comparable exposure-response (PKPD) relationship for either compound between adults and children. Two weight bands were identified for gabapentin, with doses titrated from 5 to 63 mg/kg. This yields gabapentin exposures (AUC0-8 ) of approximately 35 mg/L*h (1200 mg/day adult dose equivalent). For tramadol, median steady state concentrations between 200 and 300 ng/mL were achieved after doses of 2-5 mg/kg, but concentrations showed high interindividual variability. Simulation scenarios showed that titration steps are required to explore therapeutically relevant dose ranges taking into account the safety profile of both drugs. Gabapentin can be used t.i.d. at doses between 7-63 and 5-45 mg/kg for patients receiving gabapentin weighing <15 and ≥15 kg, respectively, whereas a t.i.d. regimen with doses between 1 and 5 mg/kg can be used for tramadol in patients who are not fast metabolisers.

Results Reporting and Early Termination of Childhood Obesity Trials Registered on ClinicalTrials.gov

Objective

Childhood obesity is one of the most severe challenges of public health in the twenty-first century and may increase the risk of various physical and psychological diseases in adulthood. The prevalence and predictors of unreported results and premature termination in pediatric obesity research are not clear. We aimed to characterize childhood obesity trials registered on ClinicalTrials.gov and identify features associated with early termination and lack of results reporting.

Methods

Records were downloaded and screened for all childhood obesity trials from the inception of ClinicalTrials.gov to July 29, 2021. We performed descriptive analyses of characteristics, Cox regression for early termination, and logistic regression for lack of results reporting.

Results

We identified 1,312 trials registered at ClinicalTrials.gov. Among clinicalTrials.gov registered childhood obesity-related intervention trials, trial unreported results were 88.5 and 4.3% of trials were prematurely terminated. Additionally, the factors that reduced the risk of unreported outcomes were US-registered clinical studies and drug intervention trials. Factors associated with a reduced risk of early termination are National Institutes of Health (NIH) or other federal agency funding and large trials.

Conclusion

The problem of unreported results in clinical trials of childhood obesity is serious. Therefore, timely bulletin of the results and reasons for termination remain urgent aims for childhood obesity trials.

Use of available clinical evidence to extrapolate drug effects from adults to children

The extrapolation of the benefit risk ratio from adults to children is performed during drug development and often implicitly used by many paediatricians when prescribing off-label drugs in children. This is due to the specific constraints of paediatric clinical research leading to a lack of safety and efficacy data in children. Extrapolation frameworks for drug development have been proposed by several regulatory agencies. Using a meta-epidemiological approach, we explored the similarities and differences of the benefit, the benefit risk ratio and the perceived placebo effect between adults and children from meta-analyses including randomized double-blinded placebo-controlled trials evaluating a drug intervention in an indication in adults and children with separate data for both populations. We also explored the use of the effect model using adult data to predict the treatment effect in children and to calibrate future paediatric clinical trials. Our research highlights the importance of using all available evidence and quantitative methods before extrapolating the benefit risk ratio from adults to children and carrying out new studies in the context of the existing evidence. More generally, this should be applied to any research to avoid a waste of time and resources invested.

Reducing waste in pediatric clinical research

The importance of reducing waste and increasing value when conducting research has been emphasized by a series of articles published in the Lancet in 2014. A survey indicates that, one year later, these articles have not influenced how research is conducted. In this review, we explore four stages described by Moher et al. in research production that lead to waste. We show that all four stages including, questions relevant to users, appropriate design conduct and analysis, accessible full research, unbiased and usable reports, efficient research regulation and management of biomedical research are also producing an important waste in pediatric research. We conclude that methods to improve research quality and limit waste need to be implemented in pediatric research and recognized by authorities as a priority.

Pharmacoepidemiology in pediatrics: Needs, challenges and future directions for research

Despite international initiatives to promote clinical research in pediatrics, there are still many gaps of knowledge in the use of drugs to treat this specific population. When important information cannot be derived only from clinical trials, use of available observational research tools is required. In this paper, we provide an overview of the particular interest of pharmacoepidemiological research into the evaluation of drug effects in children and adolescents. We also sought to underline the unique challenges and specific needs regarding this research. Implementation of innovative methodologies and expansion of database networks to perform necessary studies could further improve performances of observational research.

Off-label and unlicensed drug use in children population

INTRODUCTION

Off-label (OL) and unlicensed (UL) drug use is widely developed in the pediatric population according to previous reviews published in the early 2010s. The present study is a narrative review of the literature of OL-UL drug use from 2013.

METHODS

We performed a literature search of research articles assessing OL-UL drug use in children (<18 years-old) published in Medline^® from January 2013 until May 2017.

RESULTS

Twenty-seven studies were included. OL drug use was defined by inappropriate age, indication, dosage or way of administration according to the summary of product characteristics in >80% of studies. UL drug used was defined by the use of drugs not licensed in the country or modifications of licensed drugs in >70% of studies. Among in- and out-patients, the frequency of patients exposed to at least one OL-UL drug ranged from 36.3 to 97.0% and from 18.6 to 40.2%, respectively. Drug use was categorized as OL mostly due to inappropriate age, dosage or indication. OL-UL drug use was the most prevalent in newborns (mainly preterms) and pre-school children (aged 2-5years). Various drugs were involved, depending on patients' age. Polypharmacy and long hospital stays were risk factors for OL-UL drug use. Whether OL-UL drug use leads to a higher incidence of adverse drug reactions is a controversial finding.

CONCLUSIONS

OL-UL drug use is frequent in children. A standardized definition of OL-UL drug use is needed to better assess its frequency, risk factors and impact.

Effect of grass sublingual tablet immunotherapy is similar in children and adults: A Bayesian approach to design pediatric sublingual immunotherapy trials

BACKGROUND

Large sample sizes are needed for sublingual immunotherapy (SLIT) trials because of inherent data variability secondary to inconsistent allergen exposure. Obtaining large sample sizes for pediatric SLIT trials is challenging, but a Bayesian approach using prior adult data can reduce the necessary sample size.

OBJECTIVE

We sought to describe how a Bayesian framework using prior information from adult trials can be used to improve pediatric SLIT clinical development.

METHODS

Data were compiled by using a frequentist approach (conventional clinical trial approach independent of prior data) from trials conducted during the clinical development of timothy grass SLIT-tablets.

RESULTS

The treatment effect of timothy grass SLIT-tablets was considered similar between pediatric (n = 795) and adult (n = 2299) data pools, with relative total combined symptom plus medication score improvement versus placebo of 21% (95% CI, 11.0% to 30.4%) and 20% (95% CI, 14.6% to 24.4%), respectively. Phleum pratense-specific IgG₄ and IgE-blocking factor increased from baseline in both children and adults treated with timothy grass SLIT-tablets. Given the reasonable assumption in similarity of treatment response between adults and children, a Bayesian approach is described to demonstrate rigorous efficacy criteria for pediatric trials incorporating information from prior adult trials and thereby reduce the sample size.

CONCLUSIONS

Data support the similarity of efficacy and immunologic changes between children and adults treated with SLIT for allergic rhinoconjunctivitis. Therefore it is appropriate to use data from adult trials to design feasible trials in children, which might reduce unsafe off-label use by promoting more quickly proper labeling of approved products.

[Justification of off-label antibiotics uses in hospitalized children]

Unlicensed and off-label (UL/OL) drugs are commonly used in pediatrics wards, especially the antibiotics. It remains unclear if this strategy is justified by randomized controlled trials of good quality?

OBJECTIVE

The aim of this study was to compare the level of evidence of UL/OL antibiotics prescription in hospitalized children. The initial hypothesis was that the UL/OL antibiotics prescriptions had a lower level of evidence than licensed antibiotics.

METHOD

This observational study assessed the antibiotics prescription in the children mother and women hospital of Lyon. Each antibiotic medicine courses was classified depending on: (i) they were licensed, UL or OL, (ii) their level of evidence for efficiency (sufficient evidence, insufficient evidence, no evidence) and (iii) the existence or not of randomized controlled trials (RCT) or not. The antibiotics medicine courses in atypical cases were excluded (rare disease, lack of diagnosis, comorbidities modifying antibiotic use). Data were collected with computerized patient file data. The data were compared using Fisher exact test and χ².

RESULTS

One hundred and eight medicine courses were identified, corresponding to 72 mono, bi or tri-antibiotic therapies administered to 62 patients; 34% were OL and 66% were licensed. No prescriptions were UL. Thirty-two prescriptions were excluded from the evidence assessment. No proof of efficiency was found for any of the 76 analyzed medicine courses. RCTs were found for 36 of the analyzed medicine courses (47%); licensed medicine courses were significantly more justified by RCTs than UL/OL medicine courses (63% vs. 16%, P<0.001).

DISCUSSION

This study has shown the absence of RCTs of good quality to justify the prescriptions of antibiotics in pediatrics, regardless their license status. Nevertheless, the licensed prescriptions have shown more data of efficiency than OL prescriptions. Still, even when data were found, no antibiotics prescriptions reach the threshold of good quality studies. New clinical trials should respond to the patient needs.

Is the perceived placebo effect comparable between adults and children? A meta-regression analysis

BACKGROUND

A potential larger perceived placebo effect in children compared with adults could influence the detection of the treatment effect and the extrapolation of the treatment benefit from adults to children. This study aims to explore this potential difference, using a meta-epidemiological approach.

METHODS

A systematic review of the literature was done to identify trials included in meta-analyses evaluating a drug intervention with separate data for adults and children. The standardized mean change and the proportion of responders (binary outcomes) were used to calculate the perceived placebo effect. A meta-regression analysis was conducted to test for the difference between adults and children of the perceived placebo effect.

RESULTS

For binary outcomes, the perceived placebo effect was significantly more favorable in children compared with adults (β = 0.13; P = 0.001). Parallel group trials (β = -1.83; P < 0.001), subjective outcomes (β = -0.76; P < 0.001), and the disease type significantly influenced the perceived placebo effect.

CONCLUSION

The perceived placebo effect is different between adults and children for binary outcomes. This difference seems to be influenced by the design, the disease, and outcomes. Calibration of new studies for children should consider cautiously the placebo effect in children.

The Impact of Clinical Trials Conducted by Research Networks in Pediatric Critical Care

OBJECTIVES

Research networks in adult and neonatal critical care have demonstrated collaborative and successful execution of clinical trials. Such networks appear to have been relatively recently established in the field of pediatric critical care. The objective of this study was to evaluate the productivity and impact of randomized controlled trials conducted by pediatric critical care research networks, compared with nonnetwork trials.

DATA SOURCES, STUDY SELECTION, AND DATA ABSTRACTION

We searched multiple online databases including MEDLINE, reference lists of randomized controlled trials, and relevant systematic reviews. Independent pairs of reviewers identified published randomized controlled trials administering any intervention to children in a PICU and abstracted data. A research network was defined as a formal consortium or collaborative research group established for the purpose of conducting clinical research. Data were independently abstracted in duplicate.

MAIN RESULTS

There were 288 pediatric critical care randomized controlled trials published in English between 1986 and July 2015, of which 15 randomized controlled trials (5.2%) were conducted by a total of five research networks. Network randomized controlled trials were more often multicentered, multinational, and larger in size (p < 0.001), compared with nonnetwork randomized controlled trials. Accordingly, their trials took longer to complete (median, 36 vs 21 mo; p < 0.001). Early stopping occurred in 46.7% of network randomized controlled trials (46.7%) and 27% of nonnetwork randomized controlled trials (p = 0.14), most commonly for futility. None of the network, but 45% of the nonnetwork trials found a significant difference in their primary outcome (p < 0.001). Network trials were more frequently cited (median, 6 vs 2 citations per year) and published in higher impact journals (median impact factor, 21.8 vs 3; p < 0.001).

CONCLUSIONS

Research networks have conducted a minority of randomized controlled trials in pediatric critical care. They infrequently demonstrate significant differences in their primary outcomes. Despite this, network trials are cited more frequently and appear to have greater impact. There are important lessons to learn from both individual researchers as well as research networks that may guide the successful conduct of collaborative, high-quality randomized controlled trials in critically ill children.

Children in clinical trials: towards evidence-based pediatric pharmacotherapy using pharmacokinetic-pharmacodynamic modeling

INTRODUCTION

In pediatric pharmacotherapy, many drugs are still used off-label, and their efficacy and safety is not well characterized. Different efficacy and safety profiles in children of varying ages may be anticipated, due to developmental changes occurring across pediatric life.

AREAS COVERED

Beside pharmacokinetic (PK) studies, pharmacodynamic (PD) studies are urgently needed. Validated PKPD models can be used to derive optimal dosing regimens for children of different ages, which can be evaluated in a prospective study before implementation in clinical practice. Strategies should be developed to ensure that formularies update their drug dosing guidelines regularly according to the most recent advances in research, allowing for clinicians to integrate these guidelines in daily practice. Expert commentary: We anticipate a trend towards a systems-level approach in pediatric modeling to optimally use the information gained in pediatric trials. For this approach, properly designed clinical PKPD studies will remain the backbone of pediatric research.