Recombinant adeno‐associated virus (rAAV) has emerged as an attractive gene delivery vector platform to treat both rare and pervasive diseases. With more and more rAAV‐based therapies entering late‐stage clinical trials and commercialization, there is an increasing pressure on the rAAV manufacturing process to accelerate drug development, account for larger trials, and commercially provide high doses. Still, many of the pre‐clinical and clinical manufacturing processes are tied to outdated technologies, which results in substantial production expenses. Those processes face challenges including low productivity and difficult scalability, which limits its ability to provide for required dosages which in turn influences the accessibility of the drug. And as upstream efforts are expected to increase productivities, the downstream part needs to adapt with more scalable and efficient technologies. In this review, both traditional and novel rAAV downstream technologies are presented and discussed. Traditional rAAV downstream processes are based on density gradient ultracentrifugation and have been shown to effectively purify rAAVs with high yields and purities. However, those processes lack scalability and efficiency, which is why novel rAAV downstream processes based on column‐chromatography have emerged as an attractive alternative and show potential for integration in continuous processes, following the principle of next‐generation manufacturing.

The transition from batch-wise to integrated continuous manufacturing of biopharmaceuticals has gained significant attention over the past decade. While this concept has been thoroughly studied, there remains significant room for improvement in terms of process automation and real-time monitoring. This study showcases the implementation of an integrated downstream process at a lab scale, operating continuously and autonomously. The purification process included solvent/detergent-mediated virus inactivation in a packed bed reactor, Protein A capture via a three-column periodic counter-current chromatography process with UV-based loading, and a mixed-mode chromatography polishing step in flow-through mode. Support systems for at-line automated sample collection and high-performance-liquid chromatography analysis for near-real-time quality monitoring, along with autonomous buffer management, were introduced. The process operated for over five days, with two disturbances introduced: decreased capture column capacity and increased harvest titer. The high level of automation and control allowed the process to adapt to these disturbances. Throughout the run, the product was sampled, and quality analyses were performed, achieving an average monomer content of >98.5 % and an overall yield >90 %. This study demonstrates the feasibility of introducing autonomous integrated continuous downstream processes at a lab scale, enabling users to concentrate on process and control development.

The downstream process of monoclonal antibodies (mAbs) is expensive and significantly contributes to overall manufacturing costs. One primary reason is the extensive consumption of water and chemicals required for preparing large volumes of various buffers, essential for multiple chromatography and filtration steps. Reducing the water consumption in biopharmaceutical processes is critical to drive down costs and improve sustainability, which can be achieved through the introduction of buffer recycling. In this study, we implemented buffer recycling in an integrated two-step mAb downstream process consisting of a Protein A capture step in a periodic counter-current (PCC) set-up, followed by a mixed-mode polishing step in flowthrough mode. Buffer recycling was implemented during the cleaning-in-place (CIP) phases of the integrated steps, where the CIP buffer from the polishing column was recovered and reused counter-currently in the CIP phase of the capture column. Compared to the reference process without buffer recycling, this approach resulted in 29% savings in CIP buffer, while maintaining product purity within 0.66% and yield within 1.68% of the reference process. These minor differences confirm that buffer recycling can be implemented without compromising product quality. Through buffer recycling, we see significant potential to improve process sustainability in biomanufacturing by conserving water and reducing chemical waste.

The transition from batch-wise to integrated continuous manufacturing of biopharmaceuticals has gained significant attention over the past decade. While this concept has been thoroughly studied, there remains significant room for improvement in terms of process automation and real-time monitoring. This study showcases the implementation of an integrated downstream process at a lab scale, operating continuously and autonomously. The purification process included solvent/detergent-mediated virus inactivation in a packed bed reactor, Protein A capture via a three-column periodic counter-current chromatography process with UV-based loading, and a mixed-mode chromatography polishing step in flow-through mode. Support systems for at-line automated sample collection and high-performance-liquid chromatography analysis for near-real-time quality monitoring, along with autonomous buffer management, were introduced. The process operated for over five days, with two disturbances introduced: decreased capture column capacity and increased harvest titer. The high level of automation and control allowed the process to adapt to these disturbances. Throughout the run, the product was sampled, and quality analyses were performed, achieving an average monomer content of 94% and an overall yield above 90%. This study demonstrates the feasibility of introducing autonomous integrated continuous downstream processes at a lab scale, enabling users to concentrate on process and control development.