ABSTRACT
BACKGROUND: Pompe disease is a rare genetic disorder caused by a deficiency of a lysosomal enzyme called acid alpha-glucosidase and is classified into infantile and late-onset forms. Since 2006, an enzyme replacement therapy involving alglucosidase alfa has been available. In 2021, a new enzyme replacement therapy involving avalglucosidase alfa demonstrated improved clinical benefits. In this article, the authors describe the pharmacokinetics of avalglucosidase alfa using a population pharmacokinetic approach. METHODS: The population pharmacokinetic model was developed using a data set that included 75 patients and 2042 plasma drug concentrations determined through enzymatic activity assay from 3 studies (phases I/II and III) and involved 3 dose levels (5, 10, and 20 mg/kg). The analysis was performed using NONMEM software. RESULTS: Two sequences were observed in the plasma drug concentration profile: the first kinetic driving exposure, and after 12 hours postdose, a slight rebound addressing very low concentrations that lasted up to 2 weeks. Following model screening, a model with a central compartment with parallel linear and nonlinear elimination and 2 concatenated peripheral compartments was proposed. A putative back-redistribution of a marginal fraction of the drug from the second peripheral compartment to the central compartment may explain the slight rebound in concentration. The final model's mean bias and precision for individual predictions were -2.66% and 30.7%, respectively, and -0.433% and 38.9%, respectively, for population predictions. CONCLUSIONS: A concatenated 3-compartment model was developed to describe the avalglucosidase alfa concentrations in patients with late-onset Pompe disease. None of the covariates tested could explain the interindividual variability.
Subject(s)
Glycogen Storage Disease Type II , Adolescent , Adult , Humans , Enzyme Replacement Therapy , Glycogen Storage Disease Type II/drug therapy , Glycogen Storage Disease Type II/etiology , Kinetics , Clinical Trials, Phase I as Topic , Clinical Trials, Phase II as Topic , Clinical Trials, Phase III as TopicABSTRACT
Avalglucosidase alfa (AVAL) was approved in the United States (2021) for patients with late-onset Pompe disease (LOPD), aged ≥ 1 year. In the present study, pharmacokinetic (PK) simulations were conducted to propose alternative dosing regimens for pediatric LOPD patients based on a bodyweight cut-off. Population PK (PopPK) analysis was performed using nonlinear mixed effect modeling approach on pooled data from three clinical trials with LOPD patients, and a phase 2 study (NCT03019406) with infantile-onset Pompe disease (IOPD: 1-12 years) patients. A total of 2257 concentration-time points from 91 patients (LOPD, n = 75; IOPD, n = 16) were included in the analysis. The model was bodyweight dependent allometric scaling with time varying bodyweight included on clearance and distribution volume. Simulations were performed for two dosing regimens (20 mg/kg or 40 mg/kg) with different bodyweight cut-off (25, 30, 35 and 40 kg) by generating virtual pediatric (1-17 years) and adult patients. Corresponding simulated individual exposures (maximal concentration, Cmax and area under the curve in the 2-week dosing interval, AUC2W), and distributions were calculated. It was found that dosing of 40 mg/kg and 20 mg/kg in pediatric patients < 30 kg and ≥ 30 kg, respectively, achieved similar AVAL exposure (based on AUC2W) to adult patients receiving 20 mg/kg. PK simulations conducted on the basis of this model provided supporting data for the currently approved US labelling for dosing adapted bodyweight in LOPD patients ≥ 1 year by USFDA.
Subject(s)
Glycogen Storage Disease Type II , Adult , Humans , Child , United States , Glycogen Storage Disease Type II/drug therapy , Glycogen Storage Disease Type II/chemically induced , Glycogen Storage Disease Type II/epidemiology , alpha-Glucosidases/adverse effects , alpha-Glucosidases/metabolism , Body Weight , KineticsABSTRACT
From potent and selective inhibitors of GSK3beta displaying CYP1A2 inhibition and poor PK properties, mostly linked to metabolic instability and in vivo hydrolysis of the amide bond, we were able to obtain safe and orally available inhibitors with good half lives.
Subject(s)
Glycogen Synthase Kinase 3/antagonists & inhibitors , Glycogen Synthase Kinase 3/metabolism , Protein Kinase Inhibitors/pharmacology , Protein Kinase Inhibitors/pharmacokinetics , Animals , Cytochrome P-450 CYP1A2/metabolism , Cytochrome P-450 CYP1A2 Inhibitors , Glycogen Synthase Kinase 3 beta , Humans , Mice , Models, Molecular , Protein Kinase Inhibitors/chemistryABSTRACT
From an HTS hit, a series of potent and selective inhibitors of GSK3beta have been designed based on a Cdk2-homology model and with the help of several crystal structures of the compounds within Cdk2.
