Are Adaptive Trials Ready For Primetime?
It is well-known that many patients volunteer for clinical trials because they mistakenly believe that the goal of the trial is to improve outcomes for the volunteers. A type of trial that does attempt to improve outcomes for those who enter into the trial late is the adaptive trial. In adaptive trials investigators change the enrollment and treatment procedures as the study gathers data from the trial about treatment efficacy. For example, if a study compares a new drug against a placebo treatment and the drug appears to be working, subjects enrolling later will be more likely to receive it. The idea is that adaptive designs will attract more study volunteers.
As pointed out in a couple of recent commentaries, however, there are many unanswered questions about this type of trial. A major concern is the problem of unblinding that may occur with this design with resulting problems with allocation of patients to groups. Frequent peeks at the data may influence decisions made by monitoring boards, investigators and participants. Another issue is the unknown ability to replicate adaptive trials. Finally, there are ethical questions such as the issue of greater risk for early enrollees compared to risk for later enrollees.
For further information see—
1. Adaptive Trials in Clinical Research: Scientific and Ethical Issues to Consider
van der Graaf R, Roes KC, van Delden JJ. Adaptive Trials in Clinical Research: Scientific and Ethical Issues to ConsiderAdaptive Trials in Clinical Research. JAMA. 2012 Jun 13;307(22):2379-80. PubMed PMID: 22692169.
2. Adaptive Clinical Trials: A Partial Remedy for the Therapeutic Misconception?
Meurer WJ, Lewis RJ, Berry DA. Adaptive clinical trials: a partial remedy for the therapeutic Misconception?adaptive clinical trials. JAMA. 2012 Jun 13;307(22):2377-8. PubMed PMID: 22692168.