The conventional drug development pathway involves phase 1, 2 and 3 trials of increasing size. However, more flexible models are being introduced, including phase 2/3 adaptive designs, which provide scope to reduce development time or costs, or increase the amount of information that can be obtained from a single study.
In an adaptive trial, changes can be made as a trial progresses – but only in carefully defined and pre-specified ways. One use of adaptive trials is to compare a range of different treatments: interim data analyses may reveal differences in the efficacy of treatments, or lack of efficacy, so use of certain treatments can be halted.
Use of adaptive trials is relatively new and trial design is more complex. Statistical experts in adaptive trial design should be involved at all stages of such studies.