Functional Activity (Potency)

Abstract

Because of the molecular structural complexity of a biologic, including its many possible structural variants, functional activity assays are required that can discern which structures have what amount of potency. In this chapter, the three types of functional activity assays for measuring potency will be examined: bioassay, surrogate (analytical), and assay matrix. In addition, it will be shown that the development, optimization, and validation of these potency assays can be implemented by a clinical phase-appropriate approach. Finally, it will be stressed that most manufac- turers underestimate the amount of resources and time needed to properly implement these functional activity assays. Keywords