Comprehensive overview of Antibody-Drug Conjugates (ADCs), covering their background, evolution, and the latest advancements in novel ADC subtypes, including bispecific ADCs and multiple payload ADCs. It will also explore Preclinical Safety, Efficacy, and Characterization (SEC) study design, highlighting key considerations in pharmacokinetics, toxicology, and species selection. Lastly, the session will examine challenging toxicology cases, addressing unexpected findings in ADC development.