Bioanalysis Of Biosimilars

By BARRY van der STRATE, PhD, Associate Director of Science, Large Molecules, PRA Health Sciences; CHAD BRISCOE, PhD Executive Director of Science & Innovation Bioanalytical Services, PRA Health Sciences

Assessment of biosimilarity during non-clinical and clinical trials requires specific bioanalytical procedures. The concentration of the biosimilars and their reference compounds is established using pharmacokinetic (PK) methods. Immunogenicity assays are used to determine and further characterize any anti-drug antibodies (ADA) formed during these studies. These analytical methods are pivotal for establishing similarity of biosimilar products as compared to their reference compounds. Therefore, correct development, validation, and accurate performance are essential for the successful development of any biosimilar. Although various guidance documents were published by health authorities regarding the clinical aspects of biosimilar development and different guidelines are available on method validation, no specific guidelines exist for the challenging characteristics of method validation in support of biosimilar trials. This includes important choices regarding specific methods for the biosimilar itself in relation to its reference compounds as well as the selection of specific reagents and positive controls. While various white papers were published on this topic, no full consensus has been achieved to date. This report describes the position and recommendations of PRA Health Sciences for PK and immunogenicity bioanalysis in support of biosimilar development.