Thursday, February 18 2016, 12:30pm Cohel Room, Statistics Building Valdimir Dragalin Janssen Pharmaceuticals, Johnson and Johnson Population enrichment strategy offers a specific adaptive design methodology to study the effect of experimental treatments in various sub-populations of patients under investigation. Instead of limiting the enrollment only to the enriched population, these designs enable the data-driven selection of one or more pre-specified subpopulations at an interim analysis and the confirmatory proof of efficacy in the selected subset at the end of the trial. In this presentation, the general hypothesis testing methodology and designing issues when planning such a design will be reviewed but the focus will be on the estimation of treatment effects after such adaptive tests.