A new approach to monitoring glycosylation during glycoprotein production

PROJECT SUMMARY During the production of therapeutic biologicals, glycosylation has been identified as a critical quality attribute (CQA) that must be carefully monitored to ensure that the desired protein stability, immunogenicity, antibody effector function, pharmacological safety and potency, and serum half-life are consistently obtained. Many factors can affect the composition of the glycan chains during production, such as media, temperature, dissolved gases, induction times, etc., and consequently variations in glycosylation are among the leading causes of pharmaceutical batch rejection. Currently, the characterization of protein glycosylation relies heavily on methods that employ chromatography and/or mass spectrometry, which require a high level of expertise, are time-consuming and costly, and, because they are challenging to implement during biologics production at-line, are generally performed only post-production. In recognition of the continuing need for novel analytical technologies that can be used during therapeutic production, the US Food and Drug Administration (FDA) encourages the adoption of new process analytical methods (PAT) that offer mechanisms to design, analyze, or facilitate the measurement of process parameters that affect CQAs. Here we propose to optimize and commercialize a simplified approach for monitoring glycosylation features during glycoprotein production, which we call GlycoSenseTM, that is fully aligned with the FDA PAT initiative. The GlycoSense technology uses flow cytometry with glycan-specific reagents conjugated to multiplex beads to provide a rapid, inexpensive, and easy-to-use method for monitoring protein glycosylation patterns. Flow cytometry was chosen as the preferred platform because the data are statistically robust, the equipment is relatively commonplace, the analyses consume very low quantities of sample, and it will enable Lectenz Bio to leverage its proprietary expertise in producing carbohydrate-sensing reagents. In preliminary studies reported here, GlycoSense performance metrics were established and published using glycans and glycoprotein standards. In phase II, the technology will be optimized for monitoring glycosylation changes during cell culture. This will result in GlycoSense kits that can be used for a variety of applications in basic research and in biopharma.