Draft for Consultation

level: aDvanceD F or most biopharmaceuticals, potency is assessed in a bioassay by comparing dose–response curves of the test material and a reference standard. As with all analytical techniques, such assays require criteria by which their execution can be judged objectively to be valid, regardless of whether the desired or expected result is obtained for the test sample. The purpose of this paper is to provide guidance on setting assay acceptance criteria (AAC) for potency assays based on multiwell plates. Multiple components of the overall assay system — from instruments to incubation media — need to be within defined limits to permit execution of a valid assay, so they are tested for suitability either before or during the assay. Because of the complexity of bioassay systems, not every relevant factor can be controlled. Thus, it is necessary to rely strongly on analysis of data produced by each individual assay to determine whether that assay was executed correctly. This paper discusses criteria that can be applied to the assay results and the importance of assay design in selecting useful acceptance criteria.