Compatibility of immunogenicity guidance by the EMA and the US FDA.

The guidelines for immunogenicity studies by the European Medicines Agency and the US FDA are based on different legislations and regulatory philosophies. In spite of the different background, the main guidelines are compatible on the scientific level, especially for new innovative therapeutic protein products. The importance of sensitive and drug-tolerant antidrug antibody assays and multidisciplinary approach to development and assessment are highlighted by both agencies. The main differences are in the field of biosimilars. The nonclinical in vivo immunogenicity studies are seen more useful by the FDA than by the European Medicines Agency. The draft FDA guidance on interchangeability will complicate global biosimilar development by requiring clinical switch studies with US sourced reference product.