Abstract: In recent years, modeling and simulation technology based on pharmacometrics has received increasing attention in the development of innovation drugs. In August of 2021, FDA issued a guidance named Pharmacokinetic-Based Criteria for Supporting Alternative Dosing Regimens of Programmed Cell Death Receptor-1 (PD-1) or Programmed Cell Death-Ligand 1 (PD-L1) Blocking Antibodies for Treatment of Patients with Cancer Guidance for Industry, claiming the necessity of using population PK-based simulation method for the optimization of dosing regimens, and the corresponding implementation standards. This article first summarized the existing therapeutic regimens of PD-1/PD-L1 blocking antibodies in clinic as well as the main content of the guidance, and then cited some actual examples where population PK-based simulation method did contribute to the approval of the alternative dosing regimens. Besides, some critical considerations for the dosing regimen optimization of PD-1/PD-L1 blocking antibodies were also analyzed. In our view, this guidance would have positive impacts on the development of PD-1/PD-L1 blocking antibodies in the future. We hope that this article may provide some references for the colleagues in China.

Key words: pharmacometrics, population pharmacokinetics, model simulation, model-informed drug development