Charge heterogeneity characterization of naked and drug conjugated monoclonal antibody by anion-exchange chromatofocusing method

Abstract EN

Monoclonal antibody (mAb) and their drug conjugates (ADC) are a very important class of biopharmaceuticals.

Assessing charge variant profiles is one of the tools used to insure the quality of this therapeutic class.

The main objective of the present study was to evaluate the effects of some anion exchange chromatofocusing conditions on the characterization of charge profile of a volumes, naked mAb and its drug conjugate.

The investigated conditions included pre-gradient column temperature, pH of start and elution buffers, and the addition of carrier ampholytes 8- 10.5.

The chromatofocusing results showed that mAb-1 had two major peaks corresponding to pI values, 8.1 and 8.2.

The chromatofocusing profile of studied conjugated mAb-1 demonstrated its charge heterogeneity with pI values ranged from 7.3 to 8.5.

The selectivity of the method was tested by analyzing another antibody mAb-2.

mAb-2 was more homogeneous and basic than mAb-1, with major peak corresponding to pI values 8.7.

The recommended optimal chromatofocusing conditions were applied for monitoring the stability of the studied conjugated antibody under stress conditions.

The developed chromatofocusing method can successfully be used to assess any modifications in the charge variant profile of monoclonal antibody and their drug conjugates.