Adaptive Enrichment Designs with Sample Size Re-Estimation R package esDesign version 1.0.3 CRAN Task View: ClinicalTrials (https://CRAN.R-project.org/view=ClinicalTrials) Software of 'esDesign' is developed to implement the adaptive enrichment designs with sample size re-estimation presented in Lin et al. (2021) <doi: 10.1016/j.cct.2020.106216>. In details, three-proposed trial designs are provided, including the AED1-SSR (or ES1-SSR), AED2-SSR (or ES2-SSR) and AED3-SSR (or ES3-SSR). In addition, this package also contains several widely used adaptive designs, such as the Marker Sequential Test (MaST) design proposed Freidlin et al. (2014) <doi:10.1177/1740774513503739>, the adaptive enrichment designs without early stopping (AED or ES), the sample size re-estimation procedure (SSR) based on the conditional power proposed by Proschan and Hunsberger (1995), and some useful functions. In details, we can calculate the futility and/or efficacy stopping boundaries, the sample size required, calibrate the value of the threshold of the difference between subgroup-specific test statistics, conduct the simulation studies in AED, SSR, AED1-SSR, AED2-SSR and AED3-SSR. Software Depends: R (>= 3.2.0) Imports: stats Suggests: knitr, rmarkdown Zhao Yang <yangz98@connect.hku.hk> Comprehensive R Archive Network (CRAN) Zhao Yang, Ruitao Lin, Guosheng Yin and Ying Yuan GPL-2 2021-07-13 application/tgz https://CRAN.R-project.org/package=esDesign doi:10.32614/CRAN.package.esDesign