An extension to a 2-in-1 adaptive design with biomarker subpopulation selection

In a recent article, Jin and Zhang (2022) proposed an adaptive 2-in-1 design which can expand an ongoing Phase 2 trial with multiple treatment or dose arms into a confirmatory Phase 3 trial with the selected arms based on interim data, and proved that the design can preserve the familywise Type I error rate under a mild assumption. The proposed adaptive design provides an efficient pathway to combine the treatment or dose selection stage and the confirmatory stage into one trial and can expedite drug development. Here we extend the adaptive 2-in-1 design by Jin and Zhang (2022) to an adaptive 2-in-1 design with biomarker subpopulation selection with a similar framework.