Integrated Longitudinal Population Dose-Hemoglobin Response of Daprodustat Following Dose Titration in Patients With...

Daprodustat, a novel oral hypoxia-inducible factor prolyl hydroxylase inhibitor is approved in the United States for the treatment of anemia due to chronic kidney disease (CKD) in adults receiving dialysis for at least 4 months. Pharmacodynamic dose-hemoglobin (Dose-Hgb) models were developed as daprodustat progressed through development. To support global phase III development, a dose-titration algorithm, guided by simulations from the initial Dose-Hgb model based on phase II clinical data, was implemented. This work was to update and re-calibrate this model to support the dose titration algorithm. Data from five pivotal phase III studies in CKD patients with anemia treated with daprodustat once daily (q.d.) and/or three times a week (t.i.w.) using a titration dosing schedule were included. The data comprised 2,770 CKD patients with anemia providing 53,535 Hgb observations over a period of 6 months up to 4 years. This final Dose-Hgb model consisted of a precursor cell compartment and 12 transit compartments to describe the red blood cell (RBC) lifespan. Treatment increased the precursor cell production rate (K_in) by a power of allometrically scaled dose. Disease progression, as an exponential decline of Hgb production rate over time, varied with dialysis status. The dose-titration algorithm resulted in comparable response for t.i.w. dosing relative to q.d. dosing. Titration-based visual predictive checks for Hgb target criteria for the analysis dataset and the prediction dataset showed that the model adequately predicted the observed data. This re-calibrated Dose-Hgb model will provide further support for the individualized dosing strategy in CKD patients with anemia treated with daprodustat.