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Review
. 2018 Feb 10;8(2):e018320.
doi: 10.1136/bmjopen-2017-018320.

Adaptive design clinical trials: a review of the literature and ClinicalTrials.gov

Laura E Bothwell  1 , Jerry Avorn  1 , Nazleen F Khan  1 , Aaron S Kesselheim  1
Affiliations
Review

Adaptive design clinical trials: a review of the literature and ClinicalTrials.gov

Laura E Bothwell et al. BMJ Open. .

Abstract

Objectives: This review investigates characteristics of implemented adaptive design clinical trials and provides examples of regulatory experience with such trials.

Design: Review of adaptive design clinical trials in EMBASE, PubMed, Cochrane Registry of Controlled Clinical Trials, Web of Science and ClinicalTrials.gov. Phase I and seamless Phase I/II trials were excluded. Variables extracted from trials included basic study characteristics, adaptive design features, size and use of independent data monitoring committees (DMCs) and blinded interim analyses. We also examined use of the adaptive trials in new drug submissions to the Food and Drug Administration (FDA) and European Medicines Agency (EMA) and recorded regulators' experiences with adaptive designs.

Results: 142 studies met inclusion criteria. There has been a recent growth in publicly reported use of adaptive designs among researchers around the world. The most frequently appearing types of adaptations were seamless Phase II/III (57%), group sequential (21%), biomarker adaptive (20%), and adaptive dose-finding designs (16%). About one-third (32%) of trials reported an independent DMC, while 6% reported blinded interim analysis. We found that 9% of adaptive trials were used for FDA product approval consideration, and 12% were used for EMA product approval consideration. International regulators had mixed experiences with adaptive trials. Many product applications with adaptive trials had extensive correspondence between drug sponsors and regulators regarding the adaptive designs, in some cases with regulators requiring revisions or alterations to research designs.

Conclusions: Wider use of adaptive designs will necessitate new drug application sponsors to engage with regulatory scientists during planning and conduct of the trials. Investigators need to more consistently report protections intended to preserve confidentiality and minimise potential operational bias during interim analysis.

Keywords: EMA; FDA; adaptive design; clinical trial; data monitoring committee; flexible design; history; interim analysis; policy; regulation; review.

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Conflict of interest statement

Competing interests: All authors have completed the ICMJE uniform disclosure form at www.icmje.org/coi_disclosure.pdf and declare: ASK had financial support from the Laura and John Arnold Foundation and Harvard Program in Therapeutic Science and LEB had support from Brigham and Women’s Hospital Innovation Hub for the submitted work; no financial relationships with any organisations that might have an interest in the submitted work in the previous three years; no other relationships or activities that could appear to have influenced the submitted work.

Figures

Figure 1
Figure 1
Flow diagram derived from preferred reporting items for systematic reviews and meta-analyses (PRISMA). This diagram reports results of a search for published adaptive design clinical trials in Web of Science database on 17 September 2014; in PubMed, EMBASE and Cochrane Registry of Controlled Clinical Trials databases on 22 October 2014 and in ClinicalTrials.gov on 20 June 2015.
Figure 2
Figure 2
Prevalence of adaptive design type in surveyed trials. Adaptive trials first appeared in ClinicalTrials.gov search results in 2002; data prior to 2002 reflect only literature review results and data after 2002 reflect combined literature review and ClinicalTrials.gov results.
Figure 3
Figure 3
Duration and sample size of adaptive and standard Phase II and III trials. Phase II and III adaptive and standard trials, including median durations in weeks, as well as median participant sample sizes. Each dot represents a trial.
Figure 4
Figure 4
Sources of funding for adaptive design clinical trials. Number of trials receiving funding from each type of source. Data prior to 2002 reflect only literature review results and data after 2002 reflect combined literature review and ClinicalTrials.gov results.
See this image and copyright information in PMC

Comment in

References

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