Improving AAV8 purification with continuous affinity capture: From batch to continuous multicolumn chromatography

The increasing demand for adeno-associated viruses (AAVs) in gene therapy is driving the development of more efficient and scalable purification processes. This study explored different batch and continuous multicolumn chromatography (MCC) approaches for AAV8 affinity resin purification using the Resolute® BioSMB PD platform. Starting with a description of the breakthrough behaviour, we defined a continuous loading strategy by dividing a single chromatography bed into smaller, connected columns. This continuous batch multicolumn chromatography (B-MCC) process was then modified into a version where the columns were overloaded to enhance productivity and resin utilization. The different approaches were compared regarding recovery, productivity, buffer consumption, and resin utilization. The continuous sequential multicolumn chromatography (S-MCC) process developed enables higher AAV recovery in comparison to the B-MCC process, with a recovery of 76 % for the highest load concentration evaluated, with a productivity of 1.8 × 10¹⁷ VP h^-1 mL^-1, 1.5 times higher than the B-MCC. Additionally, for the same volume of processed feed, the S-MCC halves the buffer consumption compared to the B-MCC. Our results demonstrate that S-MCC significantly improves overall process efficiency, offering higher recovery and productivity while reducing resource consumption. These results strongly support the broader application of continuous processing techniques in the biopharmaceutical industry, particularly for high-demand biologics such as AAV.