Adaptive Trial Design
A clinical trial that allows pre-planned modifications to the study design based on interim data analysis, such as adjusting sample size, dropping ineffective dose arms, or modifying randomisation ratios. Adaptive designs can improve efficiency while maintaining statistical validity.
Technical Context
Adaptive designs pre-specify interim analyses that can modify: sample size (based on observed treatment effect), randomisation ratio (shift more patients to promising arms), dose levels (drop futile arms, add new arms), patient population (enrich for responders), endpoints, or trial duration. These modifications must be planned before the trial starts and defined in the statistical analysis plan — post hoc changes are not adaptive design. Bayesian adaptive designs use accumulating data to update probability distributions. Adaptive platform trials (e.g. I-SPY for cancer) can continuously add and drop treatments. For peptide drug development, adaptive Phase II designs can efficiently identify optimal doses from multiple candidates while controlling overall Type I error rate.