Background and objectives: Dorzagliatin is a first-in-class small molecule glucokinase activator (GKA) that improves pancreatic insulin secretion behavior and regulates hepatic glucose conversion in a glucose concentration-dependent manner. The primary objective of this study was to develop a population pharmacokinetic model of dorzagliatin to evaluate the influence of covariates, such as demographic characteristics and liver and kidney function, on the pharmacokinetics of dorzagliatin and provide a basis for medication guidance.

Method: The pharmacokinetic data of dorzagliatin in this study came from six clinical trials. Based on the combined data, a population pharmacokinetic model of dorzagliatin was established using NONMEM software (ICON, MD, USA, version 7.4.3). The algorithm used was first-order conditional estimation with interaction (FOCEI). The dorzagliatin population pharmacokinetic modeling analysis included 1062 subjects and 7686 observable concentrations. Covariates, including age (AGE), sex (GEND), body weight (TBW), body mass index (BMI), body surface area (BSA), albumin (ALB), alanine aminotransferase (ALT), aspartate aminotransferase (AST), serum creatinine (CR), creatinine clearance (CRCL), and total bilirubin (TBIL), were screened using the forward-backward method. Model evaluation was performed using goodness-of-fit plots, prediction corrected visual prediction check (pcVPC), and bootstrap.

Results: Concentration data of dorzagliatin in the dose range were best characterized by a two-compartment model with sequential zero-order then first-order absorption and first-order elimination. The final model estimated dorzagliatin data for typical male subjects (69 kg body weight, 18 U/L AST and 55 years old); the apparent total clearance (CL/F) was 10.4 L/h, apparent volume of central compartment distribution (Vc/F) was 80.6 L, inter-compartmental clearance (Q/F) was 3.02 L/h, apparent volume of peripheral compartment distribution (Vp/F) was 26.5 L, absorption rate constant (Ka) was 3.29 h-1, and duration of zero-order absorption (D1) was 0.418 h. The inter-individual variation of CL/F, Vc/F, Vp/F, and D1 was 22.5%, 14.9%, 48.8%, and 82.8%, respectively.

Conclusion: The two-compartment linear pharmacokinetic model with zero- and first-order sequential absorption adequately described the pharmacokinetic characteristics of dorzagliatin. Body weight, aspartate aminotransferase, and age had a statistically significant effect on the CL/F of dorzagliatin. Body weight and sex had a statistically significant effect on Vc/F. However, considering the clinically insignificant changes in the magnitude of steady-state exposure caused by these covariates, as well as the minimal changes in the steady-state exposure for individuals with mild and moderate impaired hepatic function and all stages of renal impairment, dose adjustments based on the tested covariates or for specific populations are deemed unnecessary.