Effect of Multiple Doses of Sparsentan on the Single-Dose Pharmacokinetics of Dapagliflozin: An Open-Label Drug–Drug Interaction Study in Healthy Adults
Clinical Pharmacology in Drug Development – 2023
Physiologically-based pharmacokinetic (PBPK) models can be used to predict pharmacokinetics (PK) and drug-drug interactions (DDIs) of based on physiological, chemical, preclinical, and clinical data.2
Sparsentan is a dual endothelin type A receptor (ETAR) and angiotensin II subtype 1 receptor (AT1R) antagonist3; in vitro studies of sparsentan show that it may induce or inhibit the activity of cytochrome P450 (CYP) enzymes, which play a key role in the metabolism and clearance of many drugs.1,4 In particular, sparsentan is thought to inhibit and induce CYP2C9, CYP2C19, and CYP3A4.1
The aim of this study was to develop and verify a PBPK model of sparsentan PK and simulate the potential DDIs for sparsentan as both a victim and perpetrator.1
Model development
A PBPK model was developed using Simcyp™ PBPK Simulator (a software package for predicting drug behavior in the human body).1 This model incorporated in vitro data including1:
Model verification and application
The PBPK model was verified using data from various clinical studies of sparsentan, specifically1:
The verified model was used to simulate DDIs of sparsentan with several drugs not studied in the clinical trials.1
Under various conditions, the validated PBPK model predicted PK and DDIs of sparsentan that were consistent with data from clinical studies1
The model predicted plasma concentration-time profiles for sparsentan consistent with data from clinical studies in single and multiple doses (ranging from 50-1600 mg) and could also predict food effects.1
Sparsentan is a victim and perpetrator of CYP3A4 DDIs1
The model also consistently predicted the observed effect of itraconazole on sparsentan (increased exposure) and the minimal interaction of sparsentan and midazolam reported in clinical studies.1
Sparsentan can act as DDI victim or perpetrator1
DDI modeling of sparsentan as a victim showed sparsentan exposure within two-fold of control for all inducers/inhibitors at both steady-state or a single dose, except for fluconazole.1
Predicted area under the curve (AUC) DDI-to-control ratio:
As a perpetrator, sparsentan 800 mg at steady state had no or minimal impact on predicted exposures on the CYP3A4 and CYP2C19 substrates, midazolam or omeprazole.1
P-gp inhibition had a negligible effect on sparsentan1
Simulations of complete inhibition of P-gp-mediated transport in the gut and liver showed a negligible effect on sparsentan exposure.1
This PBPK model evaluated the interactions between CYP450 enzymes and sparsentan as either a perpetrator or victim and contributed to the growing knowledge of DDIs.1 This model may be helpful in evaluating the risks of DDIs of sparsentan in people with IgA nephropathy.1
AT1R, angiotensin II subtype 1 receptor; AUC, area under the curve; CYP, cytochrome P450; DDI, drug-drug interaction; ETAR, endothelin type A receptor; IgA, immunoglobulin A; PBPK, physiologically-based pharmacokinetic; P-gp, P-glycoprotein; PK, pharmacokinetics.
MA-SP-24-0098 | September 2024