rpact – R Programming for Adaptive Clinical Trials

Presentation for the U.S. Food and Drug Administration (FDA), March 3, 2022, 9:00am - 11:00am EST

Professor Gernot Wassmer, Ph.D. and Friedrich Pahlke, Ph.D.

Session Description: The focus of this webinar will be on adaptive group sequential designs and an R package to implement such designs and analyses. rpact is a comprehensive validated, open source, free-of-charge R software package for clinical research planning, design evaluation and analysis which:

  • Enables the design of confirmatory adaptive group sequential designs
  • Provides interim data analysis including early efficacy stopping and futility analyses
  • Enables sample-size reassessment with different strategies
  • Enables treatment arm selection in multi-stage multi-arm (MAMS) designs
  • Provides a comprehensive and reliable sample size calculator.


  • 9:05 - 9:30: Basic Concept
  • 9:30 - 10:15: Sample Size Calculations, Simulation, and Analysis
  • 10:15 - 10:45: Multi-Arm and Enrichment Designs
  • 10:45 - 11:00: Q&A / Discussion

The interest was great: 128 participants from the FDA attended the presentation.


Presentation for the U.S. Food and Drug Administration (FDA), March 3, 2022, 9:00am - 11:00am…

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Online Training Course for PPD, January 13, 2022.

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“rpact is by far the easiest to use.”
(Professor Daniel Lakens, Human-Technology Interaction Group, Eindhoven University of Technology, The Netherlands)



“We regularly use rpact for the design of group-sequential and adaptive trials at our company. The package is continuously evolving and includes state-of-the-art methods such as estimation of…



“[…] it is an incredibly accessible and useful tool for sequential analyses. […] I think your rpact package and shiny app might be a bit of a game-changer on this front, as it makes the required…