Table III.
Parameter Estimates for Pharmacokinetic-Pharmacodynamic Model. A, Parameters Estimated by Control, RTV and DOC Groups; B, Parameter Estimated by Control, RTV, DOC and DOC+RTV Groups
| A | B | ||||||
|---|---|---|---|---|---|---|---|
| Control, RTV, DOC groups | Control, RTV, DOC, DOC+RTV groups | ||||||
| Parameters | Units | Estimate | RSE (%) | Shrinkage (%) | Estimate | RSE (%) | Shrinkage (%) |
| Population parameter | |||||||
| Baseline tumour volume (BASE) | mm3 | 214 | 3.1 | – | 211 | 1.4 | – |
| Net tumour growth rate in untreated groups (Kg0) | /week | 1.18 | 5.7 | – | 1.32 | 3.4 | – |
| Progression appearance factor (LAMBDA) | /week | 0.11 | 16.0 | – | 0.061 | 10.1 | – |
| Cell transition rate by docetaxel to effect compartment (KKDOC) | /week | 1.81 | 4.6 | – | 1.90 | 2.1 | – |
| Cell elimination rate by docetaxel from effect compartment (KKeDOC) | /week | 2.93 | 18.2 | – | 4.62 | 10.1 | – |
| Docetaxel tumour concentration with 50% of maximum anti-cancer effect (EC50DOC) | ng/g | 96.5 | 62.9 | – | 310 | 15.0 | – |
| Cell transition rate by ritonavir to effect compartment (KKRTV) | /week | – | – | – | 0.0054 | 17.4 | – |
| Cell elimination rate by ritonavir from effect compartment (KKeRTV) | /week | – | – | – | 7.45 | 4.6 | – |
| Between-subject variability | |||||||
| Baseline tumour volume (BASE) | CV% | 22.5 | 10.5 | 7.9 | 21.4 | 7.0 | 9.1 |
| Residual unexplained variability | |||||||
| Proportional residual error on tumour volumes | CV% | 23.0 | 10.0 | 3.4 | 24.8 | 8.7 | 2.8 |
CV coefficient of variation, DOC docetaxel, RSE relative standard error, RTV ritonavir