A general approach for testing a prespecifeid subgroup in clinical trials
*Mohamed Ahmad Alosh, FDA 

Keywords: consistency, alpha-level adaptive strategy

Subgroup analyses are commonly used in clinical trials with the objective of learning about differential treatment effect across subgroups. Due to power consideration among other factors, clinical trials are seldom considered for establishing an efficacy claim for a subgroup in case the trial fails to establish an efficacy claim for the total population. In this presentation we consider a multiple testing strategy for the total population and a priori identified subgroup with the following features: (i) ensuring consistency of efficacy findings of the total population and that of the subgroup so that the results of the study overall are interpretable and (ii) allowing the significance level for testing the subgroup to adapt to the efficacy findings of the total population in a general form. We consider application of the proposed methodology to clinical trial data.