Considerations for the design and conduct of pediatric obesity pharmacotherapy clinical trials: Proceedings of expert roundtable meetings

Abstract

Anti-obesity medications (AOMs) have emerged as one element of comprehensive obesity clinical care intended to improve long-term health outcomes for children and adolescents. The number of pediatric AOM clinical trials has burgeoned in recent years as new pharmacotherapeutics have been developed. Factors related to growth and development in children and adolescents can present unique challenges in terms of designing and conducting clinical trials investigating the safety and efficacy of AOMs. These barriers can delay the AOM development and evaluation process, increase the cost of performing trials, create challenges in the interpretation of results, influence the generalizability of the findings and present ethical dilemmas. In an effort to address these issues and provide guidance to streamline the process of designing and conducting pediatric AOM clinical trials, relevant key stakeholders convened a series of roundtable meetings to discuss, debate and achieve harmonization on design features. Stakeholder participants included a multidisciplinary group of international pediatric obesity experts, patient (parent) representatives and representatives from academic medicine, key regulatory agencies and industry. Topics of discussion included primary efficacy end-points, secondary end-points, eligibility criteria, trial run-in and follow-up phases, use of active comparators and guidelines for down-titration and/or stopping rules for excessive weight reduction. Consensus recommendations were agreed upon. Regarding end-points, emphasis was placed on moving away from BMI z-score as a primary outcome, incorporating multiple alternative BMI-related outcomes and measuring adiposity/body fat as a prominent secondary end-point. Trial eligibility criteria were carefully considered to maximize generalizability while maintaining safety. The limited value of trial run-in phases was discussed. It was also underscored that designing trials with extended follow-up periods after AOM withdrawal should be avoided owing to ethical issues (including possible psychological harm) related to weight regain without providing the opportunity to access other treatments. The panel emphasized the value of the randomized, placebo-controlled trial but recommended the thoughtful consideration of the use of active comparators in addition to, or instead of, placebo to achieve clinical equipoise when appropriate. Finally, the panel recommended that clinical trial protocols should include clear guidance regarding AOM down-titration to avoid excessive weight reduction when applicable.