Strategies for removing two "problematic" host cell proteins, using an "end-to-end" approach

Area of Science:

• Biopharmaceutical Manufacturing
• Protein Chemistry
• Process Development

Background:

• Host cell proteins (HCPs) are critical impurities in recombinant protein biopharmaceuticals, potentially affecting product safety and efficacy.
• Two specific HCPs, heat shock protein 90 beta and perilipin-4-like, were identified in a Chinese hamster ovary (CHO) cell line during Immunoglobulin G subclass 1 (IgG1) monoclonal antibody process development.
• A risk assessment identified these HCPs as "problematic," necessitating the establishment of target removal levels.

Purpose of the Study:

• To explore conditions that minimize deviations from the platform process while effectively controlling problematic HCP levels.
• To investigate upstream and downstream process modifications for reducing specific HCPs in an IgG1 monoclonal antibody process.
• To establish target levels for problematic HCPs to guide removal strategies.

Main Methods:

• An end-to-end approach was employed, evaluating downstream purification steps such as Protein A washes, polishing chromatography, and depth filtration.
• Upstream process parameters, including temperature shifts and modulation of iron and citrate concentrations, were investigated.
• Risk assessment included HCP identification, homology analysis with human proteins, and review of non-clinical and clinical data.

Main Results:

• Optimized upstream and downstream conditions were identified that effectively reduced the levels of the two problematic HCP species.
• The study demonstrated the successful implementation of process modifications to meet drug substance targets for HCP removal.
• Both upstream and downstream levers contributed to the effective control of heat shock protein 90 beta and perilipin-4-like.

Conclusions:

• The developed strategies effectively control problematic host cell proteins in recombinant monoclonal antibody production.
• Optimizing both upstream and downstream processes is crucial for managing critical impurities like HCPs.
• This study provides a framework for controlling specific HCPs to ensure biopharmaceutical safety and efficacy.