Fitting PK/PD Models to Published Data with admixr2

The nlmixr2 Working Group introduces admixr2 for fitting pharmacometric models to published aggregate data and model-based meta-analysis summaries in R.
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Author

R Consortium

Published

July 6, 2026

The nlmixr2 logo: a hexagonal sticker with a red border featuring nlmix in dark blue and r squared in red, with www.nlmixr2.org along the bottom edge

Original post on the nlmixr2 project blog is here.

The nlmixr2 Working Group continues to expand what open-source R tooling can support in pharmacometrics. In a new technical post, the team introduces admixr2, an R package that fits PK/PD models directly to aggregate published data, such as mean concentration-time profiles, standard deviations, and published model estimates, when individual patient data are unavailable because of privacy, access, or competitive constraints.

The post shows how admixr2 integrates with the familiar nlmixr2/rxode2 ini()/model() syntax to model digitized mean ± SD profiles from the literature, derive aggregate data from published NLME models for meta-analytic model-based analysis (MBMA), and combine multiple study summaries in a single joint fit.

Read the full post from the nlmixr2 blog: Fitting PK/PD models to published data with admixr2

Why nlmixr2?

The vision of nlmixr2 is to develop a R-based open-source nonlinear mixed-effects modeling software package that can compete with commercial pharmacometric tools and is suitable for regulatory submissions.

In short, the goal of nlmixr2 is to support easy and robust nonlinear mixed effects models in R.

From: https://github.com/nlmixr2/nlmixr2

Get involved in the nlmixr2 working group

The nlmixr2 working group is open to anyone interested in contributing to the project. You can get involved by:

Main repo: https://github.com/nlmixr2/nlmixr2
Issues: https://github.com/nlmixr2/nlmixr2/issues
Discussions: https://github.com/nlmixr2/nlmixr2/discussions