The role of bioassays in the assessment of recombinant proteins

Although the need is diminishing, biological assays still have an important place in the characterization and quality control of therapeutic peptides prepared by recombinant DNA technology. This role needs to be assessed on a case-by-case, product-by-product basis. It includes as a minimum the need to establish during product development the range and quantitative nature of its biological activities, particularly those relevant to its intended clinical use and potential side effects. For those products whose quality and consistency can be established by alternative approaches, then a biological assay may no longer be necessary on a batch basis. For others, bioassays will be required until adequate and appropriate alternatives can be shown, through international collaborative studies, to be sufficient to assure the product's efficacy and safety in clinical use. So-called "bio-identity" tests are inappropriate and should not be used.