Continuous precipitation-filtration process for initial capture of a monoclonal antibody product using a four-stage countercurrent hollow fiber membrane washing step

The significant increase in product titers, coupled with the growing focus on continuous bioprocessing, has renewed interest in using precipitation as a low-cost alternative to Protein A chromatography for the primary capture of monoclonal antibody (mAb) products. In this work, a commercially relevant mAb was purified from clarified cell culture fluid using a tubular flow precipitation reactor with dewatering and washing provided by tangential flow microfiltration. The particle morphology was evaluated using an inline high-resolution optical probe, providing quantitative data on the particle size distribution throughout the precipitation process. Data were obtained in both a lab-built 2-stage countercurrent washing system and a commercial countercurrent contacting skid that provided 4 stages of continuous washing. The processes were operated continuously for 2 h with overall mAb yield of 92 & PLUSMN; 3% and DNA removal of nearly 3 logs in the 4-stage system. The high DNA clearance was achieved by selective redissolution of the mAb using a low pH acetate buffer. Host cell protein clearance was 0.59 & PLUSMN; 0.08 logs, comparable to that based on model predictions. The process mass intensity was slightly better than typical Protein A processes and could be significantly improved by preconcentration of the antibody feed material.

Automated summary

The use of precipitation as a low-cost alternative to Protein A chromatography has gained renewed interest due to increased product titers and the focus on continuous bioprocessing. In this study, a commercially relevant monoclonal antibody (mAb) was purified from cell culture fluid using a tubular flow precipitation reactor and tangential flow microfiltration for dewatering and washing. The results showed high mAb yield, DNA removal, and comparable host cell protein clearance, making precipitation a promising primary capture method for mAb products.