Fully integrated continuous bioprocessing of recombinant proteins using mammalian cells

PROJECT ASSIGNED TO: Daniel Paul KOMUCZKI

With the release and the embracement of recent QbD/PAT guidelines as “best practice” for process development by regulatory authorities a new trend in the biopharmaceutical industry towards integrated continuous bioprocessing (ICB) was introduced [1]. These guidelines aim to establish an in depth process understanding for the manufacturing process to be able to define on the one hand critical process parameters (CPPs – e.g. DO) and on the other hand critical quality attributes (CQAs – e.g. Glycosylation) which are affecting the protein of interest. Furthermore, to monitor and control respective CPPs and CQAs during the manufacturing process for a real-time release of the POI [2]. Important to realize is, that in contrast to conventional fed batch operations ICB requires continuous monitoring and control and, therefore, process intervention. If e.g. upon a fluctuation certain CQAs are out of acceptable ranges, process parameters or media/buffer components could be adapted to tailor the respective CQAs. For example, it has been demonstrated that by shifting of process parameters such as temperature the behaviour of the cell culture can be controlled [3]–[5]. However, also media components might be altered to simplify respective downstream unit operations [6]–[8]. Besides that, ICB offers also a higher volumetric productivity, smaller industrial footprint, flexibility, superior quality and reduced residence time of proteins.

On the downside, one of the biggest disadvantages of continuous bioprocessing technology is the high media/resin usage, complexity and the related logistic challenges [17]. Moreover, the definition of a batch from a regulatory point of view is a critical aspect especially when dealing with fluctuations during the bioprocess [16]. Thus, a major challenge for performing this transition is how to reduce manufacturing and research and development (R&D) costs. One strategy to tackle this challenge is to efficiently integrate individual unit operations into a fully continuous lab scale process and develop lab scale model system to generate the necessary data base for the required depth of process understanding. Another strategy is to leverage the information generated by the integration of the unit operation for advanced process monitoring and control. Finally, also rapid prototyping of new continuous technologies with superior characteristics especially in terms of their ease of integration into a continuous bioprocess can be used. By means of e.g. 3D-printing, offering the capacity to generate new prototypes within hours or days, rather than weeks or months, a strategy of “fail early, fast and often” and consequently reduced the R&D cost can be pursued.

Henceforth, the objective of this doctoral thesis is to first establish up-stream processes in various process modes. A (semi-) continuous downstream process based on traditional technology (chromatography) will be developed and integrated. Consequently, bottlenecks for a fully ICB e.g. media/buffer preparation will be identified and new technologies will be explored to alleviate those bottlenecks.