A comprehensive approach for evaluating charge heterogeneity in biosimilars

Area of Science:

• Biopharmaceutical development
• Protein characterization
• Monoclonal antibody (mAb) analysis

Background:

• Charge heterogeneity is a universal characteristic of monoclonal antibodies (mAbs) and a key parameter evaluated during biosimilar development.
• Current industry practice often focuses on matching the overall charge profile of a biosimilar to its reference product.
• However, similar charge profiles may arise from different underlying mechanisms, introducing uncertainty in biosimilarity assessment.

Purpose of the Study:

• To comprehensively investigate the charge variants of a therapeutic monoclonal antibody and its biosimilar candidate.
• To compare the factors contributing to charge heterogeneity in both the reference product and the biosimilar.
• To propose a cause-based approach for charge variant evaluation in biosimilar development.

Main Methods:

• Comparative analysis of charge variants between a reference monoclonal antibody and its biosimilar candidate.
• Identification and characterization of the specific factors responsible for charge heterogeneity in both products.
• Evaluation of the suitability of a cause-based approach versus a profile-based approach for biosimilar charge assessment.

Main Results:

• The biosimilar candidate exhibited a similar overall charge profile to the reference product.
• Crucially, the same underlying factors were identified as contributing to the charge variants in both the reference and biosimilar products.
• This indicates a shared mechanism for charge heterogeneity, not just a similar outcome.

Conclusions:

• A cause-based approach for evaluating charge variants in biosimilar development is more robust than a profile-based method.
• Understanding the mechanisms driving charge heterogeneity mitigates risks associated with biosimilarity assessment.
• This rational, mechanism-driven approach enhances confidence in biosimilar product quality and comparability.