This podcast collectively provides a comprehensive overview of immunogenicity in therapeutic protein, peptide, and antibody-based products, focusing on the formation and clinical significance of anti-drug antibodies (ADAs). They explain that immunogenicity is influenced by intrinsic patient factors (genetics like HLA haplotypes, disease state) and extrinsic product factors (formulation, aggregation, dose, and route of administration). Regulatory bodies like the FDA and EMA mandate a tiered testing strategy—including screening, confirmation, titration, and functional Neutralizing Antibody (NAb) assays, often cell-based bioassays—to detect and characterize ADAs, with a specific emphasis on overcoming drug-tolerance interference. The material also details the bioanalytical complexities of newer modalities, such as Antibody-Drug Conjugates (ADCs) and CAR-T cell therapies. It highlights that ADA formation can lead to serious consequences, including loss of efficacy (PK/PD effects) and adverse events such as Pure Red Cell Aplasia (PRCA). Finally, the texts discuss mitigation strategies, including in silico risk prediction (epitope mapping) and molecular engineering (de-immunization, PEGylation), to ensure patient safety and product effectiveness throughout the lifecycle. Produced by Dr. Jake Chen.