Table 4.
Summary of models with data from intravenous administration
| Model | Ref. model | Description | OFV | ∆OFV | MS | $COV |
|---|---|---|---|---|---|---|
| Linear PK model | ||||||
| 1 | NA | Two-compartmental model with first-order elimination from central compartment | 7145.165 | – | Y | Y |
| 1a | 1 | Allometric exponents fixed to default values (0.75 for CL and one for Vc and Vp) | 7257.539 | 112.3 | Y | Y |
| Michaelis–Menten model | ||||||
| 2 | 1 | Inclusion of a nonlinear pathway (Vmax, Km) | 7021.446 | − 123.7 | Y | Y |
| Kdec on Vmax | ||||||
| 3 | 2 | Time-dependent Vmax (decreasing with time) | 6997.523 | − 23.9 | Y | N |
| CL and CLNL(t) | ||||||
| 4 | 1 | Rituximab model (CL and time-dependent CLNL) | 7136.615 | − 8.6 | Y | N |
| Covariate analysis | ||||||
| 5 | 3 | SSc Study on Vmax | 6946.843 | − 50.7 | Y | Y |
| 6 | 5 | ADAT effect on CL | 6947.309 | 0.466 | Y | Y |
| Correlation model | ||||||
| 7 | 5 | BLOCK (CL, Vmax) | 6946.794 | − 0.049 | Y | Y |
ADAT time-varying antidrug antibody, CL systemic clearance, CLNL time-dependent nonlinear clearance, MS minimization successful in NONMEM output, NA not applicable, OFV objective function value, PK pharmacokinetic, SSc systemic sclerosis, Vc volume of distribution in the central compartment, Vp volume of distribution in the peripheral compartment Vmax maximum velocity, $COV covariance step (NONMEM)