Adaptive trials in stroke: Current use & future directions

Abstract Inclusion of adaptive design features in a clinical trial provides pre-planned flexibility to dynamically modify a trial during its conduct, while preserving validity and integrity. Adaptive trials are needed to accelerate the conduct of more efficient, informative, and ethical clinical research in the field of neurology as compared to traditional fixed designs. Stroke is a natural candidate for adoption of these innovative approaches to trial design. This Research Methods in Neurology paper is informed by scoping review that identified 45 completed and ongoing adaptive clinical trials in stroke that were appraised: 14 trials had published results with or without a published protocol, 15 trials had a published protocol, and 16 trials were registered only. Treatments spanned acute (n=28), rehabilitation (n=8), prevention (n=8), and rehabilitation and prevention (n=1) domains. A subsample of these trials were selected to illustrate the utility of adaptive design features and discuss why each adaptive feature(s) were incorporated in the design to best achieve the aim, whether each individual feature was used and if it resulted in expected efficiencies, and any learnings during preparation, conduct or reporting. We then discuss the operational, ethical, and regulatory considerations that warrant careful consideration during adaptive trial planning and reflect on the workforce readiness to deliver adaptive trials in practice. We conclude that adaptive trials can be designed, funded, conducted, and published for a wide range of research questions and offer future directions to support adoption of adaptive trial designs in stroke and neurological research more broadly.