When Dr. David Bradford, Sr. Vice President and Co-Founder of PEGUS, was recently invited to write an article for the Tan Sheet, the selected topic was an exposition of key differences between efficacy and OTC actual use trials.


Key points include:


• Efficacy trials are indispensable for evaluating whether a new drug has a therapeutic effect and estimating the size of that effect. The overarching objective of the design and conduct of an experimental trial is to eliminate any alternative explanations for post-treatment differences among the treatment groups, so that the only credible explanation is the variation in the active ingredient.


• As invaluable as they are for determining efficacy, those trials do not answer some other important questions that need to be answered before a drug can be safely made available for non-prescription sale. Specifically, the results may not be broadly generalizable to an unselected population.


• The actual use trial was developed to assess the safety implications of switching a drug to non-prescription sale by showing that the ordinary consumer can execute the functions that have been managed by a physician under prescription conditions. These include correct self-diagnosis of the condition the drug treats, proper selection (taking into account the contraindicated medical conditions and concomitant drugs), and appropriate use and self-monitoring of the drug. This may also include modification or discontinuation of use (de-selection) when necessary.


• The objective of the design of an AUT is to create the conditions needed to simulate OTC drug selection and use. Consequently, a set of operations is put in place that mimic the OTC setting, and prospective subjects are recruited in ways that are as close to normal OTC drug advertising as good clinical practice permits.


• The AUT is a structured observational trial. There are no control conditions, no randomization to groups, no protocol-driven directions for drug administration, and few exclusion criteria for participation in the study. Indeed, the ideal AUT is an all-comers study, so that the degree of risk to the general population, with all its complicating circumstances, can be assessed. Thus, the public health risk of an OTC switch can be evaluated among the full range of people who self-select for use of the drug and use it in whatever way they understand they should.


• Considering all the various design alternatives for OTC-switch research, the key to appropriate scientific progress is to design studies to fit the research questions that need to be answered. The AUT is a useful and important tool in the researcher's kit, one that provides information to complement the data from other kinds of studies.


© PEGUS Research, Inc. 2016. Salt Lake City, Utah, United States. Tous droits réservés / All rights reserved.