Vadadustat is a pharmacologically or chemically characterised molecule whose biological activity, physicochemical properties, and toxicological profile have been evaluated to establish its health-based exposure limits for pharmaceutical manufacturing. Its molecular structure—defined by NMR, IR, mass spectrometry, and elemental analysis—determines receptor binding, metabolic transformation pathways, and chemical reactivity relevant to both therapeutic utility and toxicological risk assessment. ADME parameters including oral bioavailability, plasma protein binding, volume of distribution, and metabolic clearance inform toxicokinetic modelling applied during PDE derivation.
ICH Q3A qualification thresholds for impurities in new drug substances require toxicological qualification of individual impurities of Vadadustat exceeding the reporting threshold (0.05% or 1 mg TDI, whichever is lower), identification threshold (0.10% or 2 mg TDI), and qualification threshold (0.15% or 2 mg TDI).
