Bioanalytical Aspects in Biological Therapeutics

Biotransformation is one of the emerging aspects of absorption, distribution, metabolism, and elimination studies on biologics. This chapter introduces the concept of biotransformation of biologics, and its importance in the drug discovery and development process. It also introduces different mass spectrometry techniques that are utilized in the investigation of biologics biotransformation. The chapter provides detail about the biotransformation of different types of protein therapeutics. Therapeutic monoclonal antibodies (mAbs) are among the most promising and fast-growing classes of drug molecules due to several advantages such as high specificity, low off-target effect, and low attrition rate in drug discovery and development. Ligand binding assays, such as enzyme-linked immunosorbent assay, have been the gold standard for analyzing biotherapeutics such as mAbs in biological samples. Methionine oxidation is a very common modification that can impact the bioactivity and pharmacokinetic behavior of the mAb and potentially induce an immunogenic response.