Product retention in the hollow fibers is a common issue in ATF-based cell culture system. In this study, the effects of four major process factors on product (therapeutic antibody/recombinant protein) retention were investigated using Chinese hamster ovary cell. Hollow fibers made of polysulfone presented a product retention rate from 15% ± 8% to 43% ± 18% higher than those made of polyether sulfone varying with specific processes. Higher harvest flowrate and ATF exchange rate increased product retention by 13% ± 10% and up to 31% ± 13%, respectively. Hollow fibers with larger pore sizes (0.65 μm) appeared to have increased product retention by 38% ± 7% compared with smaller ones (0.2 μm) in this study. Further investigation revealed that the effects of pore size on retention could be correlated to the particle size distribution in the cell culture broth. A hollow fiber with a larger pore size (>0.5 μm) may reduce protein retention when small particles (approximately 0.01-0.2 μm in diameter) are dominant in the culture. However, if majority of the particles are larger than 0.2 μm in diameter, hollow fiber with smaller pore sizes (0.2 μm) could be a solution to reducing product retention. Alternatively, process optimization may modulate particle size distribution towards reduced production retention with selected ATF hollow fibers. This study for the first time highlights the importance of matching proper pore sizes of hollow fibers with the cell culture particles distribution and offers methods to reducing product retention and ATF column clogging in perfusion cell cultures.

WuXiUP, WuXi Biologics’ Ultra-high Productivity platform, is an intensified and integrated continuous bioprocess platform developed for production of various biologics including monoclonal antibodies, fusion proteins and bispecfic antibodies. This process technology platform has manifested its remarkable capability in boosting the volumetric productivity of various biologics and has been implemented for large scale clinical material productions. In this report, case studies of the production of different pharmaceutical proteins using two high producing and intensified culture modes of the WuXiUP and the concentrated fed-batch (CFB), as well as the traditional fed-batch (TFB) are discussed from the perspectives of cell growth, productivity, and protein quality. Both WuXiUP and CFB outperformed TFB regarding to volumetric productivity. Additionally, distinctive advantages in product quality profiles, such as charge variant, fragmentation etc., in the WuXiUP process are revealed, and therefore a simplified downstream purification process with only two chromatographic steps can be developed to deliver the target product at a satisfactory purity.

The global pandemic outbreak, SARS-COV-2, which causes COVID-19, has coerced numerous pharmaceutical companies to sprint for the vaccine and therapeutic biologics development. Most of the therapeutic biologics are common human IgG antibodies, which were identified by next-generation sequencing with the B cells from the convalescent patients in less than one-month post-infection. While the global public health emergency calls for medications urgently, it saves lives to expedite the clinical trials of biologics as much as possible, hence the biologics development strategies are unprecedentedly challenged. Since the advent of therapeutic biologics, transfection, and selection strategy has been continuously improving for developing more robust cell lines with greater productivity and efficiency. Next-generation sequencing (NGS) has also been implemented into cell bank testing for acceleration. These recent advances enable us to rethink and reshape the chemistry, manufacturing and controls (CMC) strategy against the pandemic outbreaks, to start supplying cGMP materials for the life-saving clinical trials as soon as possible. We elucidated an accelerated CMC workflow for biologics against pandemics, including using cGMP-compliant pool materials for Phase I clinical trials, selecting the final clone with similar product quality as Phase I materials for late-stage development and commercial production and matching product quality among different manufacturing stages.