Challenges and Strategies for a Thorough Characterization of Antibody Acidic Charge Variants

Area of Science:

• Biopharmaceutical characterization
• Analytical chemistry
• Protein chemistry

Background:

• Therapeutic monoclonal antibodies (mAbs) exhibit heterogeneity due to manufacturing-induced protein variants.
• These variants can impact drug safety and efficacy, necessitating their identification as critical quality attributes (CQAs).
• Previous characterization efforts often left gaps in the quantitative measurement of acidic variants.

Purpose of the Study:

• To address the challenges in characterizing and quantifying acidic variants in therapeutic mAbs.
• To improve the comprehensive analysis of protein variants in biopharmaceutical manufacturing.
• To develop and recommend updated strategies for complete antibody charge variant characterization.

Main Methods:

• Utilized a case study involving a therapeutic mAb1 with a significant proportion of acidic variants.
• Employed a well-designed study incorporating appropriate analytical methods for variant characterization.
• Focused on closing quantification gaps previously identified for acidic variants.

Main Results:

• A case study on mAb1 highlighted the prevalence of acidic variants, accounting for two-thirds of enriched variants initially.
• Additional investigations successfully closed the quantification gaps for mAb1 acidic variants.
• Demonstrated the critical role of well-designed studies and appropriate analytical methods in comprehensive characterization.

Conclusions:

• Updated strategies are recommended for more complete antibody charge variant characterization.
• Effective analytical method selection is key to successful biotherapeutic characterization.
• Addressing quantification gaps in acidic variants is essential for ensuring drug product quality and safety.