The ABIRISK project provides an integrated approach to the study of immunization against biopharmaceuticals, bringing together a unique panel of experts from different disciplines. ABIRISK will involve many of the European leaders in rheumatology, gastroenterology, hemophilia and multiple sclerosis, caring for ~30,000 patients treated with biopharmaceuticals, with ~10,000 additional patients recruited per year. This should lead to the constitution of the largest possible cohort in Europe for the study of immunogenicity, a condition critical for the success of the program. ABIRISK will also benefit from the unique expertise of immunologist partners in the development of innovative strategies for predicting the immunogenicity of biopharmaceuticals and for defining its mechanisms. The large number of patients enrolled in the ABIRISK cohorts should make it possible to study the genetic basis of immunogenicity in a new way. We will standardize all clinical and biological information before its integration into a large database for evaluation of the clinical relevance of immunization against biopharmaceuticals and stratification of the risk to patients as a function of factors linked to treatment or to the individual. Computational biology and biostatistical modeling will be used to develop models for predicting immunogenicity that will be validated with the ABIRISK database.The complementarity between the clinical partners from different disciplines, immunologists, methodologists and biostatisticians will create a unique task force for studies of biopharmaceutical immunogenicity. The direct outcomes of the proposed work will be greater understanding of the mechanisms involved in the emergence of anti-drug antibodies, the development of new methods for predicting immunogenicity and a comprehensive view of the respective value of predictive tools, and guidelines for the development of new biopharmaceuticals and patient care.