Software Download Kiosk > EffTox

Version 5.0.0, Last Modified Date: 11/3/2017


This computer program provides a basis for constructing, simulating, and conducting the EffTox phase I-II clinical trial design described in the paper “Dose-finding based on efficacy-toxicity trade-offs”, Thall and Cook, Biometrics 60:684-693,2004 [1]. Please read this paper before using this program, which implements the trial design, simulation, and conduct. Please note that as of version 4.0.0 very important improvements/refinements have been made in two key elements, (1) the prior and (2) the trade-off contour. These are explained in the tutorial, available here and in the computer program.

What's New in Version 5.0.0

  • Improved user interface, bug fixes, and a simplified code base
  • Checks for updates to the program, automatically and on demand
  • Targets the Microsoft .NET Framework 4.6.1

What was New in Versions 4.0.0 through 4.0.12

  • Very important improvements/refinements have been made in two key elements:
    1. the prior, especially regarding effective sample size (ESS), and
    2. the trade-off contour
  • Toxicity probability model constrained not to decrease with dose
  • Context-specific help and guidance on achieving a good design
  • Simulation scenarios now allow dependent outcome probabilities, if desired
  • Simulation output is now HTML
  • Much easier to use, especially trial conduct
  • Minor bug fixes and other improvements in stability, performance, and error reporting
  • Occasionally sends usage statistics and crash reports to our biostatistics software support team to improve your experience using the software


  • Windows 7
    (other Windows versions may be compatible but this has not been tested)
  • Administrative permissions may be required to install EffTox depending on the chosen installation location.
  • The following packages will be installed if they or compatible replacements are not present:
    • Microsoft .NET Framework 4.6.1
    • Microsoft Visual C++ 2013 Runtime Libraries (x86)
    • Microsoft Windows Installer 4.5
  • To view the trade-off function details a PDF file viewer (not included with the software) such as Adobe Reader (available for free here) must be installed.
  • To follow the "Send feedback via email" link in the Help -> About EffTox... window, an email client such as Microsoft Outlook (not included with the software) must be installed.


EffTox Screenshot


Clift Norris developed the original user interface using C#, C++, and the Microsoft .NET framework version 1.1. Richard Herrick, Clift Norris, Juan Posadas, and John Venier developed the current user interface using C#, C++, and the Microsoft .NET framework version 4.6.1.

John Cook implemented the original simulation kernel using Visual C++. Richard Herrick, Clift Norris, and John Venier modified it.



[1] Peter F. Thall and John D. Cook. Dose-Finding Based on Efficacy-Toxicity Trade-Offs. Biometrics 60, pp. 684-693, September 2004.

[2] Peter F. Thall and John D. Cook. Adaptive dose-finding based on efficacy-toxicity trade-offs Encyclopedia of Biopharmaceutical Statistics, 2nd Edition. Chein-Chung Chow editor. 2006

[3] Peter F. Thall, John D. Cook, and Eli Estey. Adaptive dose selection using efficacy-toxicity trade-offs: illustrations and practical considerations. Journal of Biopharmaceutical Statistics Vol 16, No. 5, pp. 623-638, 2006.