(191bl) The Introduction and Removal of ?-Glucans in a Biological Purification Process – a Case Study

Adele Pearson, Robert G. Luo, Kent E. Göklen

GlaxoSmithKline

King of Prussia, PA, USA

Poster Abstract

β-glucans are polysaccharides of D-glucose monomers linked by β-glycosidic bonds. Because they pose an immunogenicity risk to patients, drug products should have low levels of β-glucans. They can be introduced into a process through multiple sources: 1) host cell impurity from a yeast cell line; 2) component of yeastolate which may be an additive in production media; 3) leachable from cellulosic depth filters; and 4) potential contaminant in raw materials (e.g. sucrose). In this study, β-glucans were found at unexpectedly high levels in batches of the product of a mAb purification process; levels were higher than seen earlier in the program. The investigation that led to an understanding of the phenomenon and the change that caused it will be presented. In addition, the studies evaluating removal of β-glucans by filtration, including filter screening and sizing, will also be presented.