Determining biopharmaceutical critical quality signatures at the interface of upstream and downstream process development

Lead Research Organisation: University College London
Department Name: Biochemical Engineering

Abstract

Currently biopharmaceutical manufacturing processing are developed and delivered in a segregated manner spread across a number of different disciplines or units of operation. Consequently this can result in isolated upstream decision-making (eg choice of cell line and bioreactor processing parameters) thereafter haphazardly impacting downstream product purification, formulation and stability profiles. The project described herein will now focus on a systematic investigation of the interface between Downstream and Upstream Manufacturing activities. Specifically this project will aim to combine off-line with online orthogonal analytics to generate multi-factorial signatures associated with Upstream CUB (clarified unprocessed bulk) and thereafter understand how such outputs impact downstream events (including product recovery, purity, impurity and stability profiles). This more holistic approach will help identify new process intermediate critical quality CUB 'signatures' to support future Biopharmaceutical process-development, -equivalence, -validation, and -robustness strategies.

Project Detail:
Scope upstream processing parameters for a model IgG1 biopharmaceutical using different cell clones and under a range of different upstream operating conditions.
Use of off-line analytics (e.g. titre, monomer purity, HCP/DNA content, potency) to establish the effect of cell line and upstream cell culture parameters on harvested CUB (clarified unprocessed bulk) quality.
Correlate such off-line CUB quality analytics to orthogonal online signatures (eg Fluorescence, Raman etc)
Thereafter understand how such offline and online CUB fingerprints impact downstream product purification, quality, impurity and accelerated stability profile
Accordingly define online and offline CUB 'critical quality signatures'
Model a design space accordingly (including multidimensional edge-of-failure testing) to confirm the findings.
Please note: In delivering this project, the successful applicant will gain broad and invaluable experience in biopharmaceutical Upstream, Downstream, Analytical and Formulation sciences at state-of-the-art Laboratory facilities in The GSK Biopharm Unit in Stevenage.

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
BB/N503812/1 01/10/2015 30/09/2019
1632715 Studentship BB/N503812/1 28/09/2015 30/09/2019 Louisa Jane Wilson
 
Description Recent improvements in volumetric antibody productivity (often in excess of 5 g/L) have been achieved by advances in cell lines and upstream processing, but often lead to harvest material becoming more difficult to recover. These intensified upstream operations require a renewed prioritisation of the integration of upstream and downstream process development to ensure product purification issues are taken into consideration, to avoid extensive and expensive clearance strategies downstream.
Here, it was demonstrated that changes to upstream process parameters at the bioreactor stage of monoclonal antibody production affect product quantity and quality. Culture pH, temperature and seed density setpoints leading to high titre are commonly also linked to higher post-protein A HCP levels, reduced monomer percentages and increased percentages of undesirable glycan structures.
To predict post-protein A product quality, several potential indicators that can be measured in harvest material (prior to using expensive purification resources) were explored, including culture viability and osmolality, revealing unexpectedly that culture viability could not be used for such a purpose, but that osmolality has the potential to be used as a product quality indicator.
The impact of culture duration on product quality was also investigated and it was shown that as cultivation progressed and antibody titre increased, product quality declined, in one case due to post-protein A HCP levels increasing by 75% from day 14 to day 17 of culture. HCP identification by mass spectrometry was applied to this system to provide insights into cellular behaviour and HCP carryover during protein A purification. It showed increases in several classes of post-protein A HCPs (e.g. stress response proteins) as the culture progressed, particularly on days 15 and 17 of culture which were associated with significant increases in total HCP levels. This provides a new level of insight into HCPs that are retained during mAb purification which may be used to aide process development strategies.
Exploitation Route The key findings highlight the importance of adopting integrated approaches to upstream and downstream development strategies to enable whole process optimisation for the manufacture of biopharmaceuticals.
Sectors Manufacturing, including Industrial Biotechology,Pharmaceuticals and Medical Biotechnology