crmPack (version 1.0.6)

DualEndpointEmax-class: Dual endpoint model with emax function for dose-biomarker relationship

Description

This class extends the DualEndpoint class. Here the dose-biomarker relationship \(f(x)\) is modelled by a parametric EMAX function:

Slots

E0

either a fixed number or the two uniform distribution parameters

Emax

either a fixed number or the two uniform distribution parameters

ED50

either a fixed number or the two uniform distribution parameters

refDoseEmax

the reference dose \(x^{*}\)

Details

$$f(x) = E_{0} + \frac{(E_{max} - E_{0}) * (x/x^{*})}{ED_{50} + (x/x^{*})}$$

where \(x^{*}\) is a reference dose, \(E_{0}\) and \(E_{max}\) are the minimum and maximum levels for the biomarker and \(ED_{50}\) is the dose achieving half of the maximum effect \(0.5 * E_{max}\).

All parameters can currently be assigned uniform distributions or be fixed in advance.

Examples

model <- DualEndpointEmax(E0 = c(0, 100),
                          Emax = c(0, 500),
                          ED50 = c(10,200),
                          refDoseEmax = 1000,
                          mu = c(0, 1),
                          Sigma = matrix(c(1, 0, 0, 1), nrow=2),
                          sigma2W = c(a=0.1, b=0.1),
                          rho = c(a=1, b=1))