Introduction

CAMPSIS is a open-source PK/PD simulation platform built on top of the open-source simulation packages rxode2, RxODE and mrgsolve. It provides an abstraction layer over the underlying processes of writing a model, assembling a dataset and running, in the background, a simulation with these packages.

CAMPSIS is developed by software engineers working at Calvagone and designed for pharmacometricians who are looking for an easy and intuitive way to run model-based simulations. The packages are developed in R, which makes it possible to integrate your simulation(s) into an R workflow (e.g. standard R script, Rmarkdown, Shiny app, etc.).

Brief overview

As shown in the schematic below, CAMPSIS comprises two inter-connected R packages: campsismod and campsis. The first package allows the user to assemble, read, write or manipulate a PK/PD model. It also provides useful utilities to export the model to RxODE or mrgsolve. The second package allows the user to assemble the dataset in a very intuitive manner. Once the user’s dataset is ready, the package is in charge of preparing the simulation, calling RxODE or mrgsolve and returning the results, for a given model, dataset and desired simulation settings.

A quick example

Load a 1-compartment model with absorption compartment from the model library.

library(campsis)
model <- model_library$advan2_trans2

For instance, let’s adapt the population estimate for clearance.

model <- model %>% replace(Theta(name="CL", value=10))

Assume some drug is already present in the central compartment (e.g. 0.1 ng/mL with 20% CV across individuals).

model <- model %>%
  add(Theta(name="CENTRAL_INIT", value=0.1)) %>%
  add(Omega(name="CENTRAL_INIT", value=20, type="cv%")) %>%
  add(InitialCondition(compartment=2, rhs="THETA_CENTRAL_INIT*exp(ETA_CENTRAL_INIT)*V"))

Let’s now create a small dataset of 10 individuals and let’s infuse 100 mg at time 0, for a duration of 10 hours.

dataset <- Dataset(10) %>% 
  add(Infusion(time=0, amount=100, compartment=1, duration=10)) %>%
  add(Observations(0:24))

We can now simulate this very simple model and dataset.

Finally, we can use ggplot2 to plot these results.

library(ggplot2)
ggplot(results, aes(x=TIME, y=CP, group=ID)) +
  geom_line(colour="gray39", size=1) + theme_bw()

Well done, you just drew the A letter of our CAMPSIS logo.

Going further

If you haven’t installed CAMPSIS, please visit the installation section.

If you are looking for some more examples, please check out our documentation websites: