Stability enhancement in a mAb and Fab coformulation.

Area of Science:

• Biochemistry
• Protein Engineering
• Pharmaceutical Formulation

Background:

• Therapeutic protein combinations offer synergistic targeting but face formulation challenges.
• Maintaining protein activity and minimizing degradation in multi-protein doses is critical.
• Coformulation can impact protein stability and product shelf-life.

Purpose of the Study:

• To investigate the impact of coformulating a monoclonal antibody (IgG1) and a Fab fragment on their degradation kinetics.
• To understand the mechanisms behind potential protective effects during coformulation.
• To assess the feasibility of combining different therapeutic protein formats in a single formulation.

Main Methods:

• Coformulation of a therapeutic monoclonal antibody (IgG1) and a related Fab fragment.
• Analysis of degradation kinetics under mildly destabilizing conditions.
• Investigation of protein-protein interactions and aggregation pathways.

Main Results:

• Coformulated IgG1 and Fab fragments exhibited mutual protection against degradation.
• The protective effect was observed under mildly destabilizing conditions.
• Mechanisms involved interactions forming small soluble oligomers or IgG1 nuclei coalescence.

Conclusions:

• Coformulation of monoclonal antibodies and Fab fragments can enhance protein stability.
• Specific protein-protein interactions, not crowding or diffusion, drive the protective effect.
• This finding has implications for developing stable, multi-component therapeutic protein formulations.