A variation of a 2-in-1 adaptive design to seamlessly expand a selected dose from a phase 2 trial to a phase 3 trial for oncology drug development

In a recent article, Zhang et al. proposed a 2-in-1 adaptive design to seamlessly expand a selected dose, based on efficacy compared to the control arm, from a Phase 2 trial to a Phase 3 trial for oncology drug development. In this article, we communicate a variation of the proposed design which selects a dose to expand based on direct comparison of high dose to low dose when both doses demonstrate promising efficacy compared to the control arm.