Reduction of charge variants by CHO cell culture process optimization

Area of Science:

• Biotechnology
• Biopharmaceutical Manufacturing
• Protein Chemistry

Background:

• Therapeutic monoclonal antibodies (mAbs) are crucial for treating cancers and immune diseases, with increasing production yields.
• Improving mAb quality, specifically critical quality attributes (CQAs) like charge variants, is a key focus in bioprocess development.
• Bioprocess optimization is preferred over cell line or media changes for regulatory reasons.

Purpose of the Study:

• To investigate the impact of process control and ion supplementation on mAb charge variants.
• To identify optimal conditions for minimizing undesirable charge variants during mAb production in Chinese hamster ovary (CHO) cells.

Main Methods:

• Utilized 3L bioreactors for Chinese hamster ovary (CHO) cell cultures.
• Investigated the effects of zinc (Zn2+) ion concentration, culture duration, and temperature shifts on mAb charge variants.
• Analyzed changes in main and acid peaks of mAb charge variants.

Main Results:

• Zn2+ concentration, culture duration, and temperature significantly influence mAb charge variants.
• Optimal conditions involving Zn2+ and temperature shifts in 3L bioreactors increased the main peak by 12% and decreased the acid peak by 16%.
• These improvements in charge variants were achieved without a significant loss in mAb titer.

Conclusions:

• Process control, particularly Zn2+ supplementation and temperature shifts, is an effective strategy for improving mAb charge variant profiles.
• This study provides evidence for optimizing bioprocesses to enhance the quality of therapeutic mAbs.
• The findings support the development of methods to mitigate charge variants during mAb manufacturing.