Therapeutic monoclonal antibodies and consistent ends: terminal heterogeneity, detection, and impact on quality

Monoclonal antibodies (mAbs) are biological macromolecules with complex post-translational modifications that can be observed when assessing product variants. The N- and C-terminal heterogeneities of commercially produced antibodies have been observed and extensively studied over the past 30 years. This review summarizes the current literature on detectable antibody termini variants from cultured cells. The presence of these heterogeneities can be detected by many different analytical methods, mostly based on sequence, charge and size differences. Examples are presented that highlight terminal heterogeneities, methods of detection, and their impact on the quality of mAbs. Regulatory considerations are also discussed regarding the potential impact on product quality, safety, and efficacy.