Design and Simulation of Seamless Phase II-III Clinical Trials R package sp23design version 0.9-1 CRAN Task View: ExperimentalDesign (https://CRAN.R-project.org/view=ExperimentalDesign) Provides methods for generating, exploring and executing seamless Phase II-III designs of Lai, Lavori and Shih using generalized likelihood ratio statistics. Includes pdf and source files that describe the entire R implementation with the relevant mathematical details. Software Depends: R (>= 3.0) Imports: mvtnorm, survival Suggests: RUnit Balasubramanian Narasimhan <naras@stat.stanford.edu> Comprehensive R Archive Network (CRAN) Balasubramanian Narasimhan [aut, cre], Mei-Chiung Shih [aut], Pei He [aut] LGPL-3 2022-04-19 application/tgz https://CRAN.R-project.org/package=sp23design doi:10.32614/CRAN.package.sp23design