A pharmacokinetics-informed ODE extrapolates long-term fenofibrate transcriptomic responses

Long-term in vivo transcriptomic time courses are costly, limiting assessment of chronic molecular responses from short studies. We developed a pharmacokinetics-informed transcriptomic ordinary differential equation model (PKT-ODE) that links an oral pharmacokinetic profile and Hill drug-effect function to first-order turnover of co-expression modules. The model was fitted to rat liver responses to fenofibrate at three doses in Open TG-GATEs through day 8. At the held-out day-29 endpoint, PKT-ODE achieved Pearson r = 0.960 and mean squared error (MSE) = 0.148. In this dataset, these values achieved lower prediction error and higher correlation than four statistical baselines and validation-selected linear and multilayer-perceptron transition models. Literature-curated peroxisome proliferator-activated receptor target genes occurred only in modules with positive fitted drug effects. These results provide a proof of concept for pharmacokinetics-informed transcriptomic extrapolation; cross-compound, cross-organ and alternative-regimen performance remain to be tested.