Biopharmaceutical industry has focused on cancer drug research and development in the past decades, however the success rate for oncology products is relatively low compared to other therapeutic areas.The difficulty may reflect the poor understanding of Pharmacokinetic/Pharmacodynamic (PK/PD) relationships and the lack of quantitative methods to guide preclinical and clinical study design and development decision, and it could be particularly challenging for protein therapeutics with their unique PK/PD properties.This presentation will provide an overview on how PK/PD evaluation and Modeling & Simulations (M&S) may play an important role to select safe and efficacious dose regimen for biologics in cancer patients.