Table 2.
Parameter estimates from the kinetic–pharmacodynamic model
| Parameter | Estimate (RSE%) | BSV% (RSE%) |
|---|---|---|
| ke (/day) | 0.036 (22.7) | 73.88 (51.7) |
| Baseline (106/L) | 266.4 (37.8) | 98.13 (26.9) |
| kout (/day) | 0.02 (41.0) | 89.61 (108.3) |
| Emax | 35.2 (11.8) | ‐ |
| ED50 (mg) | 0.81 (190.3) | ‐ |
| covMTX | 0.66 (37.4) | ‐ |
| covCYC | 0.38 (74.4) | ‐ |
| Prop residual error (cv%) | 59.3 (14.4) | ‐ |
ke, elimination rate constant of rituximab; baseline, CD19+ lymphocyte counts at baseline; kout, death rate constant of CD19+ lymphocytes; Emax, maximum cell killing effect of rituximab; ED50, rituximab dose at 50% of maximum effect; covMTX, proportional increase in Emax with methotrexate; covCYC proportional increase in Emax with cyclophosphamide; Prop residual error (cv%), coefficient of variation for proportional variability; RSE, relative standard error; BSV, between‐subject variability.