The principle of equipoise in pediatric drug trials

Non-static framework for understanding adaptive designs: an ethical justification in paediatric trials

Many drugs used in paediatric medicine are off-label. There is a rising call for the use of adaptive clinical trial designs (ADs) in responding to the need for safe and effective drugs given their potential to offer efficiency and cost-effective benefits compared with traditional clinical trials. ADs have a strong appeal in paediatric clinical trials given the small number of available participants, limited understanding of age-related variability and the desire to limit exposure to futile or unsafe interventions. Although the ethical value of adaptive trials has increasingly come under scrutiny, there is a paucity of literature on the ethical dilemmas that may be associated with paediatric adaptive designs (PADs). This paper highlights some of these ethical concerns around safety, scientific/social value and caregiver/guardian comprehension of the trial design. Against this background, the paper develops a non-static conceptual lens for understanding PADs. It shows that ADs are epistemically open and reduce some of the knowledge-associated uncertainties inherent in clinical trials as well as fast-track the time to draw conclusions about the value of evaluated drugs/treatments. On this note, the authors argue that PADs are ethically justifiable given they (1) have multiple layers of safety, exposing enrolled children to lesser potential risks, (2) create social/scientific value generally and for paediatric populations in particular, (3) specifically foster the flourishing of paediatric populations and (4) can significantly improve paediatric trial efficiency when properly designed and implemented. However, because PADs are relatively new and their regulatory, ethical and logistical characteristics are yet to be clarified in some jurisdictions, the cooperation of various public and private stakeholders is required to ensure that the interests of children, their caregivers and parents/guardians are best served while exposing paediatric research subjects to the most minimal of risks when they are enrolled in paediatric trials that use ADs.

Participation in a single-blinded pediatric therapeutic strategy study for juvenile idiopathic arthritis: are parents and patient-participants in equipoise?

BACKGROUND

Genuine uncertainty on superiority of one intervention over the other is called equipoise. Physician-investigators in randomized controlled trials (RCT) need equipoise at least in studies with more than minimal risks. Ideally, this equipoise is also present in patient-participants. In pediatrics, data on equipoise are lacking. We hypothesize that 1) lack of equipoise at enrolment among parents may reduce recruitment; 2) lack of equipoise during participation may reduce retention in patients assigned to a less favoured treatment-strategy.

METHODS

We compared preferences of parents/patients at enrolment, documented by a questionnaire (phase 1), with preferences developed during follow-up by an interview-study (phase 2) to investigate equipoise of child-participants and parents in the BeSt-for-Kids-study (NTR 1574). This trial in new-onset Juvenile Idiopathic Arthritis-patients consists of three strategies. One strategy comprises initial treatment with a biological disease-modifying-antirheumatic-drug (DMARD), currently not standard-of-care. Semi-structured interviews were conducted with 23 parents and 7 patients, median 11 months after enrolment.

RESULTS

Initially most parents and children were not in equipoise. Parents/patients who refused participation, regularly declined due to specific preferences. Many participating families preferred the biological-first-strategy. They participated to have a chance for this initial treatment, and would even consider stopping trial-participation when not randomized for it. Their conviction of superiority of the biological-first strategy was based on knowledge from internet and close relations. According to four parents, the physician-investigator preferred the biological-first-strategy, but the majority (n = 19) stated that she had no preferred strategy. In phase 2, preferences tended to change to the treatment actually received.

CONCLUSIONS

Lack of equipoise during enrolment did not reduce study recruitment, mainly due to the fact that preferred treatment was only available within the study. Still, when developing a trial it is important to evaluate whether the physicians' research question is in line with preferences of the patient-group. By exploring so-called 'informed patient-group'-equipoise, successful recruitment may be enhanced and bias avoided. In our study, lack of equipoise during trial-participation did not reduce retention in those assigned to a less favoured option. We observed a change for preference towards treatment actually received, possibly explained by comparable outcomes in all three arms.

Lack of a Negative Effect of BCG-Vaccination on Child Psychomotor Development: Results from the Danish Calmette Study - A Randomised Clinical Trial

Objectives

To assess the non-specific effect of Bacillus Calmette-Guérin (BCG) vaccination at birth on psychomotor development.

Design

This is a pre-specified secondary outcome from a randomised, clinical trial.

Setting

Maternity units and paediatric wards at three university hospitals in Denmark.

Participants

Children born at gestational age (GA) 32 weeks and above. All women planning to give birth at the three sites were invited during the recruitment period. Out of 4262 randomised children, 144 were premature (GA < 37 weeks). There were 2129 children (71 premature) randomised to BCG and 2133 randomised (73 premature) to the control group.

Interventions

BCG vaccination 0.05 ml was given intradermally in the upper left arm at the hospital within seven days of birth. Children in the control group did not receive any intervention. Parents were not blinded to allocation.

Main outcome measures

Psychomotor development measured using Ages and Stages Questionnaire (ASQ) completed by the parents at 12 months. Additionally, parents of premature children (gestational age < 37 weeks) completed an ASQ at 6 and 22 months. Developmental assessment was available for 3453/4262 (81%).

Results

The mean difference in ASQ score at 12 months adjusted for age and prematurity was -0.7 points (BCG vs. control, 95% confidence interval; -3.7 to 2.4), p = 0.67, corresponding to an effect size of Cohen’s d = -0.015 (-0.082 to 0.052). The mean difference in ASQ score for premature children at 22 months was -7.8 points (-20.6 to 5.0, p = 0.23), d = -0.23 (-0.62 to 0.15).

Conclusions

A negative non-specific effect of BCG vaccination at birth on psychomotor development was excluded in term children.

Trial Registration

ClinicalTrials.gov NCT01694108

Clinical equipoise on prophylaxis against catheter-associated thrombosis in critically ill children

PURPOSE

In preparation for a randomized controlled trial of prophylaxis against catheter-associated deep venous thrombosis in critically ill children, we aimed to determine clinical equipoise, defined as willingness to randomize children, among pediatric critical care physicians.

MATERIALS AND METHODS

We conducted a cross-sectional, self-administered electronic survey of pediatric critical care physicians in the United States. The survey focused on the effect of child's age, presence of a central venous catheter, and risk (ie, presence of coagulopathy or recent surgery) and presence of bleeding on their willingness to randomize children to an anticoagulant or placebo.

RESULTS

Responses from 239 (33.0%) of 725 physicians were analyzed. Respondents were willing to randomize children 1 month or older in the presence of a catheter but only those older than 13 years in the absence of a catheter. For children with coagulopathy, they would randomize those with international normalized ratio less than or equal to 2.0, partial thromboplastin time less than or equal to 50 seconds, and platelet count greater than or equal to 50000/mm(3). Respondents were willing to randomize children 2 days after most types of surgery and after 1 to 5 days of a bleeding event.

CONCLUSIONS

Clinical equipoise on prophylaxis against catheter-associated thrombosis exists among pediatric critical care physicians, which ethically justifies conducting a randomized controlled trial.