Development of Top-Down Mass Spectrometry Strategies in the Chromatographic Time Scale (LC-TD-MS) for the Extended Characterization of an Anti-EGFR Single-Domain Antibody-Drug Conjugate in Both Reduced and Nonreduced Forms.

Even though mAbs have attracted the biggest interest in the development of therapeutic proteins, next-generation therapeutics such as single-domain antibodies (sdAb) are propelling increasing attention as new alternatives with appealing applications in different clinical areas. These constructs are small therapeutic proteins formed by a variable domain of the heavy chain of an antibody with multiple therapeutic and production benefits compared with their mAb counterparts. These proteins can be subjected to different bioconjugation processes to form single-domain antibody-drug conjugates (sdADCs) and hence increase their therapeutic potency, and akin to other therapeutic proteins, nanobodies and related products require dedicated analytical strategies to fully characterize their primary structure prior to their release to the market.