Confirmatory Adaptive Clinical Trial Design and Analysis
Design and analysis of confirmatory adaptive clinical trials with continuous, binary, and survival endpoints according to the methods described in the monograph by Wassmer and Brannath (2025) . This includes classical group sequential as well as multi-stage adaptive hypotheses tests that are based on the combination testing principle.

rpact 
Confirmatory Adaptive Clinical Trial Design, Simulation, and Analysis.
Functional Range
- Fixed sample design and designs with interim analysis stages
- Sample size and power calculation for
- means (continuous endpoint)
- rates (binary endpoint)
- survival trials with flexible recruitment and survival time options
- count data
- Simulation tool for means, rates, survival data, and count data
- Assessment of adaptive sample size/event number recalculations based
on conditional power
- Assessment of treatment selection strategies in multi-arm trials
- Adaptive analysis of means, rates, and survival data
- Adaptive designs and analysis for multi-arm trials
- Adaptive analysis and simulation tools for enrichment design testing
means, rates, and hazard ratios
- Automatic boundary recalculations during the trial for analysis with
alpha spending approach, including under- and over-running
Installation
Install the latest CRAN release via
install.packages("rpact")
Development version
To use a feature from the development version, you can install the
development version of rpact from
GitHub.
# install.packages("pak")
pak::pak("rpact-com/rpact")
Documentation
The documentation is hosted at www.rpact.org
Vignettes
The vignettes are hosted at
www.rpact.org/vignettes
RPACT Connect
Connecting you to insights, downloads, and premium support:
connect.rpact.com
The RPACT User Group
The rpact project has an active user group consisting of
decision-makers and users from the pharmaceutical industry and CROs, who
meet regularly and, e.g., discuss best practices.
We invite you to be part of the RPACT User Group: benefit from
know-how, shape open source development in Pharma!
Use on corporate computer systems
Please contact us to learn how to use
rpact on FDA/GxP-compliant validated corporate computer systems and
how to get a copy of the formal validation documentation that is
customized and licensed for exclusive use by your company, e.g., to
fulfill regulatory requirements. The validation documentation contains
the personal access data for performing the installation qualification
with testPackage().
www.rpact.com/contact
About
- rpact is a comprehensive validated[^1] R package for clinical
research which
- enables the design and analysis of confirmatory adaptive group
sequential designs
- is a powerful sample size calculator
- is a free of charge open-source software licensed under
LGPL-3
- particularly, implements the methods described in the recent
monograph by Wassmer and Brannath
(2025)
For more information please visit
www.rpact.org
- RPACT is a company which offers
- enterprise R/Shiny software development services
- technical support for the
rpact package
- consultancy and user training for scientists using R
- validated software solutions and R package development for clinical
research
For more information please visit
www.rpact.com
[^1]: The rpact validation documentation is available exclusively for
our customers and supporting members. For more information visit
www.rpact.com/services/sla