For bioprocess engineers and scientists, every new Mab is a new case study. And every case study, like Mab-X, is a step toward safer, more affordable biologics for patients worldwide. This article is a synthetic case study representative of standard industrial practices for monoclonal antibody development. Actual processes for commercial antibodies (e.g., Humira, Keytruda, Rituxan) vary in specifics but follow the same engineering principles outlined above.
Lowering the pH during harvest. As the culture ages, CO2 builds up, lowering pH to 6.7. Mab-X has a unique hydrophobic patch in the Fc region that is prone to unfolding at pH <6.8. A Mab A Case Study In Bioprocess Development
Protein A capacity remains stable at 40 g/L resin. Elution at pH 3.5 yields 95% purity with <0.1% aggregates. However, the low-pH elution creates a new problem: inactivation of a small fraction of Mab-X, reducing potency by 10%. 3.2 Viral Inactivation and Neutralization To ensure safety, the eluate undergoes low-pH viral inactivation (pH 3.6 for 90 minutes). For Mab-X, which is moderately acid-labile, the team adds 100 mM sodium acetate as a stabilizing excipient during this step. Post-inactivation, pH is raised to 5.5 using 2M Tris base. Analytical data confirm >4 log reduction of model viruses (xMuLV) without compromising product quality. 3.3 Polishing: Cation Exchange (CEX) and Anion Exchange (AEX) Mab-X requires two polishing steps due to a closely related charge variant (a deamidated isoform at Asn-55). For bioprocess engineers and scientists, every new Mab