FDA guidance for Immunogenicity Testing Assays: Development & Validation of Anti-drug Antibody Assays The FDA has finalized its guidance for the development and validation of assays for immunogenicity testing. The new guidance supersedes other previous guidance for related to bioanalytical assay validation for immunogenicity testing. The objective of this guidance is to facilitate the industry’s development and validation of assays for assessment of the immunogenicity of therapeutic protein products during clinical trials. More specifically the guidance provides a stepwise approach to develop, validate the anti-drug antibody assay, it helps to answer the following questions: a) Why it is important to assess immunogenicity? b) What is the ADA assay? c) When is it appropriate to develop ADA assays and assess immunogenicity? d) How to develop reliable, sensitive and specific ADA assays? a) Why it is important to assess immunogenicity? Immunogenicity is defined a...