Monitoring and determining the cause of antibody discoloration

Color is a potential critical quality attribute of protein therapeutics. Undesirable color changes can lead to increased product heterogeneity and concerns about the safety and efficacy of a drug. Hence, the cause of color change in biotherapeutics must be fully understood and reported to regulatory agencies.

This technical note highlights a streamlined solution that combines the power of capillary isoelectric focusing (cIEF) to monitor antibody discoloration and an EAD-based MAM workflow to determine the cause of color change. The cIEF profiles of the time-course forced glycation samples of NISTmAb revealed a significant increase in acidic variants in the discolored samples. EAD-based MAM was employed to identify and quantify the acidic species to assess their role in the discoloration of protein therapeutics.