Population pharmacokinetic analysis of TQ-B3203 following intravenous administration of TQ-B3203 liposome injection in Chinese patients with advanced solid tumors

TQ-B3203 is a novel topoisomerase I inhibitor liposome injection in development for advanced solid tumors, showing considerable inter-patient pharmacokinetic variability in early clinical testing. This study used plasma concentrations from a Phase I trial in Chinese patients to build a population pharmacokinetic model with Phoenix NLME, screening for covariates affecting drug disposition. Direct bilirubin and body mass index were the most influential covariates on clearance, while lean body weight affected the central compartment's volume of distribution, with model simulations confirming clinically meaningful effects on exposure. This first robust population pharmacokinetic model for TQ-B3203 provides a reference for future dose regimen decisions in its continued clinical development.