title: Reply to Comments.
authors.affiliation: Department of Biostatistics, University of North Carolina, Chapel Hill, NC, 27599.
authors.forename: Donglin
authors.initials: D
authors.lastname: Zeng
authors.affiliation: Department of Biostatistics, University of North Carolina, Chapel Hill, NC, 27599.
authors.forename: Fei
authors.initials: F
authors.lastname: Gao
authors.affiliation: Department of Biostatistics, University of North Carolina, Chapel Hill, NC, 27599.
authors.forename: Joseph G
authors.initials: JG
authors.lastname: Ibrahim
authors.affiliation: Global Biostatistical Science, Amgen Inc., One Amgen Center Drive, Thousand Oaks, CA, 91320.
authors.forename: Kuolung
authors.initials: K
authors.lastname: Hu
authors.affiliation: Global Biostatistical Science, Amgen Inc., One Amgen Center Drive, Thousand Oaks, CA, 91320.
authors.forename: Catherine
authors.initials: C
authors.lastname: Jia
mesh_terms: D017322:Clinical Trials, Phase II as Topic / Q000706:statistics & numerical data*; D006801:Humans; D018401:Sample Size