Population Pharmacokinetics of Brentuximab Vedotin in Patients With CD30-Expressing Hematologic Malignancies
Brentuximab vedotin, a CD30-directed antibody-drug conjugate (ADC), is approved for treating certain patients with CD30-expressing hematologic malignancies. Its primary mechanism of action is the targeted delivery of a microtubule-disrupting agent, monomethyl auristatin E (MMAE), to CD30-expressing cells. A population pharmacokinetic (PopPK) analysis was conducted to characterize the PK of ADC and unconjugated MMAE in patients with CD30-expressing hematologic malignancies by compartmental analysis and to evaluate the effects of covariates on PK of the ADC. A nonlinear mixed-effects modeling approach was used to evaluate data from 314 patients in 5 clinical studies. ADC PK was described by a linear, 3-compartment model with first-order elimination. MMAE PK was described by a semimechanistic, linear, 2-compartment model with first-order elimination. The estimated typical values for a 75-kg male patient were 1.56 L/d and 4.29 L for ADC systemic clearance (CL) and volume of central compartment (V1), respectively, with weight effect exponents of 0.698 and 0.503, respectively. Typical V1 in 75-kg females was 87% of that in males, with no impact on systemic ADC exposure. Typical values of MMAE clearance (CLM) and volume of central compartment (V4) were 55.7 L/d and 79.8 L, respectively, with weight effect exponents fixed to 0.75 and 1.0, respectively. This is the first PopPK model of brentuximab vedotin to semimechanistically link the PK of ADC and that of the unconjugated small molecule MMAE. Both ADC and MMAE PK data were adequately described by the final integrated model, which supports weight-based dosing of brentuximab vedotin in adult patients with CD30-expressing hematologic malignancies.