Immunogenicity and its impact on benefit/risk considerations in the authorisation of biopharmaceuticals.

Antibody formation is an intended physiological reaction to a "non-self" protein intentionally triggered in the case of vaccines. However, an unwanted immune response to a therapeutic protein may lead to a loss of efficacy and/or to severe side effects. The Committee for Medicinal Products for Human Use (CHMP) at the European Medicines Agency (EMA) issued a multidisciplinary guideline providing general recommendations from a marketing authorisation perspective on how to systematically assess an unwanted immune response following the administration of a biological drug. In this article, we discuss key aspects of this guideline and its concept, with a particular focus on the impact of immunogenicity on benefit/risk estimation of a therapeutic protein.