Population Pharmacokinetic Modeling for the Iminosugar Lucerastat Supports Dose Adaptation in Patients With Fabry Disease and Moderate to Severe Renal Function Impairment.

Lucerastat is an iminosugar with the potential to provide substrate reduction therapy for the treatment of Fabry disease (FD), an inherited X-linked lysosomal storage disorder. The aims of this study were to develop a population pharmacokinetic (PK) model describing lucerastat plasma concentration over time, to investigate the relationships between subject-specific characteristics and model parameters, and to assess the influence of these differences between subjects on lucerastat exposure via model-based simulations. Longitudinal nonlinear mixed effects modeling was applied to develop a model based on data from 250 participants in six Phase 1 and two Phase 3 studies. Lucerastat pharmacokinetics were described by a two-compartment model with linear first-order absorption and elimination, including allometric scaling of body weight on clearance and volume parameters. Lucerastat clearance was reduced in subjects with lower estimated glomerular filtration rate (eGFR). Disease status (with/without FD) was found to impact clearance and volumes of distribution to a limited extent. The model described the data well across the dose range from 100 to 4000 mg. Body weight, disease status, and renal function were shown to influence exposure, with dose adaptation only required in patients with renal function impairment, as body weight and disease status had limited impact. Dose adaptation as applied in Phase 3 (i.e., eGFR [mL/min/1.73 m