Keywords: Non-inferiority, Irritation Study
The statistical issues in irritation/sensitization study for transdermal drug products are very challenging. The purpose of irritation/sensitization study is to ensure that, in addition to the bioequivalence between the test product (TEST) and the reference listed drug (RLD) demonstrated by a comparative pharmacokinetic study, the skin irritation/sensitization is not inferior to that of the RLD. In this type of study, irritation and sensitization are assessed based on the skin irritation score (an integer ranging 0-10). The analysis endpoint is the mean skin irritation score obtained by averaging the irritation scores recorded during the evaluation period. In this presentation, we will investigate issues in analyzing irritation/sensitization study, such as the appropriate comparison scale, type of outcome (binary or continuous) and statistical model.