Expert Assessment of In Vitro Potency Assays for Monoclonal Antibody Preparations

INTRODUCTION. The quality control of biotechnological medicinal products requires a range of biological assay procedures. The development of bioassays for potency determination is a complex process that should comply with the requirements set forth in regulatory standards. For adequate reproducibility, bioassays should be properly described in draft product specification files. AIM . This study aimed to summarise the recommendations for developing in vitro bioassays for potency determination of monoclonal antibody preparations and for describing these bioassays in product specification files. DISCUSSION . This article describes the Fab- and Fc-associated biological activi­ty mechanisms of monospecific and bispecific monoclonal antibodies. The article covers in vivo and in vitro methods used to study these mechanisms, with emphasis on the reporter gene assay. The article formulates the concept and analyses the components of a holistic analytical system that is necessary for bioassay development. A well-designed analytical procedure can minimise the influence of critical factors on the test results and reduce the risks of both random and systematic errors. This article presents an estimation of the significance of detailed description of critical procedure parameters in the draft product specification file for a monoclonal antibody. CONCLUSIONS . A bioassay for the determination of potency should reflect the mecha­nism of action of the medicinal product and should provide the lowest possible variability and the highest possible ease of use. An adequate analytical procedure with appropriate analytical conditions can reduce the risk of obtaining invalid quality control results.