Antibody-Mediated Drug Delivery

Antibodies are quintessentially “information macromolecules.” Since the information resides in their antigen-binding sites, it is not surprising that most of the contributions on antibodies in this volume have focused on binding. That is, they have focused on structures and processes that influence the last few nanometers before molecular docking. Here we will consider the prior process, the pharmacokinetic path by which an antibody molecule reaches the proximity of its target antigen. That this perspective is important to the rational design of next-generation ligand molecules should require no argument. Although the title of this chapter emphasizes antibody—drug conjugates, we will focus on generic issues of pharmacology that apply to any of the forms in which antibodies (or, for that matter, other biological ligands) are used in vivo.