Demonstrating β-glucan and yeast peptide clearance in biopharmaceutical downstream processes

The use of yeast- and plant-derived hydrolysates in cell culture production processes has sparked concerns over the potential immunogenicity risk posed by β-glucans and yeast peptides contained in these raw materials. This article utilizes a combination of in-process testing from large-scale manufacturing and scale-down spiking studies to demonstrate the clearance of β-glucans and yeast peptides through chromatographic steps in the downstream purification process for a monoclonal antibody. β-Glucans were found to flow through most all three modes of chromatography (Protein A, cation and anion exchange) without binding to the resins or the product. Protein A affinity chromatography was found to provide the best clearance factor. The efficacy of the resin sanitization and storage procedures to prevent carryover from one run to the next was also demonstrated. Yeast peptides were found to be metabolized during the cell culture process and were undetectable after the Protein A purification step. The data presented here serve to allay concerns about the use of hydrolysates in cell culture production. The methodology presented here provides a template to demonstrate clearance of β-glucans and yeast peptides through chromatographic steps in downstream processing.