Adding flexibility to clinical trial designs: an example-based guide to the practical use of adaptive designs

TL;DR

This paper explains how adaptive designs in clinical trials can improve flexibility and efficiency, clarifies their features and limitations, and provides practical case studies for their application.

Contribution

It offers a comprehensive, example-based guide to understanding and implementing adaptive designs in various phases of clinical trials, addressing knowledge gaps in the clinical community.

Findings

Adaptive designs enhance trial flexibility and ethical considerations.

Proper pre-specification maintains trial validity despite adaptations.

Case studies demonstrate practical implementation across trial phases.

Abstract

Adaptive designs for clinical trials permit alterations to a study in response to accumulating data in order to make trials more flexible, ethical and efficient. These benefits are achieved while preserving the integrity and validity of the trial, through the pre-specification and proper adjustment for the possible alterations during the course of the trial. Despite much research in the statistical literature highlighting the potential advantages of adaptive designs over traditional fixed designs, the uptake of such methods in clinical research has been slow. One major reason for this is that different adaptations to trial designs, as well as their advantages and limitations, remain unfamiliar to large parts of the clinical community. The aim of this paper is to clarify where adaptive designs can be used to address specific questions of scientific interest; we introduce the main features of adaptive designs and commonly used terminology, highlighting their utility and pitfalls, and illustrate their use through case studies of adaptive trials ranging from early-phase dose escalation to confirmatory Phase III studies.