A perfusion approach at N-1, where cells stay in the exponential growth phase throughout the entire culture duration, is becoming more common as a strategy for process intensification. This is because the higher cell densities it generates allows manufacturers to skip seed stages and reduce process transfer time through multiple bioreactor sizes, thus providing more cost-effective biologics production in smaller facilities. However, this N-1 perfusion approach requires optimization. In this article, we describe the development and proof-of-concept studies with single-use rocking motion perfusion bioreactors in which we have achieved a ten-fold increase in viable cell count in N-1 seed stage, compared to the fed-batch control process, in just 6–8 days. We also mention in detail how we inoculated a 50 L bioreactor production run using this intensified seed train and show comparable growth kinetics and yield with a control process, also at 50 L scale. Using this intensification approach in the future will help our manufacturing facility, the Biopharma Division of Intas Pharmaceuticals Ltd., reach 4000 L production-scale volumes with fewer process transfer steps, and without changing the feeding strategy or production bioreactors of our biologics’ portfolio.
Tag: <span>continuous perfusion</span>
A basic engineering study has been performed to evaluate three different strategies for the production of monoclonal antibodies (MAbs) from Chinese hamster ovary (CHO) cells. Cells are expanded in suspension culture and are then inoculated into either fed batch or perfusion culture for MAb production. The first strategy, which is also the current industry standard, uses fed batch culture with the cells in suspension in a stirred tank fermenter. The second strategy uses perfusion culture with the cells immobilized on Cytopore™ microcarriers in a stirred tank fermenter. The third and final strategy is perfusion culture with Cytoline™ microcarriers in a fluidized bed fermenter. Perfusion cultures, while leading to a somewhat lower product titer, were characterized by a much smaller equipment footprint. This in turn led to a >30% reduction in investment costs and a 12% reduction in MAb production costs calculated over five years of depreciation and ten years of production time…
Building a MAb bioprocessing plant is a process which normally takes three years. Before starting the engineering work, a “locked” process is necessary. This means that all the steps have to be defined by volume, time, material balances and product yield. These calculations are based on the results obtained during process development. The titer and yield of functional, recoverable product determines the plant size. Optimal volumetric productivity [g/(liter reactor volume * day)] is of utmost importance. The main difference between fed batch and perfusion culture is that in the fed batch, a centrifuge is required for cell removal, whereas in perfusion culture, cell removal is performed by dead end filtration. This is possible because the majority of the cells are immobilised on the microcarriers, thus minimizing the burden on the clarification unit…
Single-use, disposable components offer many advantages in the manufacturing of biologics. They are clean and ready to use when supplied, which obviates the need for sterilization and decreases the requirement for services such as water for irrigation (WFI) systems and steam generators. Disposable components are not used for subsequent operations, eliminating the chance of cross contamination between process runs. Long lead times for equipment installation can be avoided because the need for stainless steel equipment is reduced or eliminated. Systems are less complex, therefore engineering requirements are also reduced. There is no need for clean-in-place (CIP) or steam-in-place (SIP) operations, along with the associated piping, valves, controls, or pressure rating of vessels. Moreover, the use of disposable components reduces the complexity of validation…
Bioreactor productivities are highly dependent on the process used to cultivate mammalian cells. These productivities directly affect the manufacturing plant capacity, and thereby the economics of production of monoclonal antibodies (MAbs). Historically, companies have chosen bioreactor process strategies that emphasize simplicity of scale-up at the expense of productivity, and conducted manufacturing using well-characterized and relatively straightforward batch processes. Such processes have successfully produced small or moderate quantities (ranging from ~100 g to ~ 1 kg per lot) of the desired antibody. Given the anticipated demand for large-scale quantities of MAbs (and the high stakes for the companies investing in these new biological entities), it is worthwhile to revisit these past selection strategies and see if — and under what conditions — they remain optimal today…