FDA perspective on specifications for biotechnology products--from IND to PLA.

Quality standards are obligatory throughout development, approval and post-marketing phases of biotechnology-derived products, thus assuring product identity, purity, and potency/strength. The process of developing and setting specifications should be based on sound science and should represent a logical progression of actions based on the use of experiential data spanning manufacturing process validation, consistency in production, and characterization of relevant product properties/attributes, by multiple analytical means. This interactive process occurs in phases, varying in rigour. It is best described as encompassing a framework which starts with the implementation of realistic/practical operational quality limits, progressing to the establishment/adoption of more stringent specifications. The historical database is generated from preclinical, toxicology and early clinical lots. This supports the clinical development programme which, as it progresses, allows for further assay method validation/refinement, adoption/addition due to relevant or newly recognized product attributes or rejection due to irrelevance. In the next phase, (licensing/approval) specifications are set through extended experience and validation of both the preparative and analytical processes, to include availability of suitable reference standards and extensive product characterization throughout its proposed dating period. Subsequent to product approval, the incremental database of test results serves as a natural continuum for further evolving/refining specifications. While there is considerable latitude in the kinds of testing modalities finally adopted to establish product quality on a routine basis, for both drugs and drug products, it is important that the selection takes into consideration relevant (significant) product characteristics that appropriately reflect on identity, purity and potency.