High yield sterile filtration process for highly concentrated lentiviral vectors

• Published in: Biotechnology journal Vol. 19; no. 3; pp. e2300348 - n/a
• Main Authors: Vogel, Jessica E., Terrao, Monica, Schwingal, Sarah, Kapitza, Laura, Brigulla, Daniel, Pirzas, Vicky, Laux, Holger, Brandt, Tobias
• Format: Journal Article
• Language: English
• Published: Germany 01.03.2024
• Subjects: Filtration - methods; gene therapy; Genetic Therapy; lentiviral vector; Lentivirus - genetics; process development; sterile filtration; Viruses - genetics; sterile filtration; gene therapy; process development; lentiviral vector
• ISSN: 1860-6768; 1860-7314
• DOI: 10.1002/biot.202300348

The development and manufacture of biopharmaceuticals are subject to strict regulations that specify the required minimum quality of the products. A key measure to meet these quality requirements is the integration of a sterile filtration step into the commercial manufacturing process. Whereas common procedures for most biologics exist, this is challenging for lentiviral vector (LVV) production for ex vivo gene therapy. LVVs nominal size is more than half the pore size (0.2 µm) of filters used for sterile filtration. Hence, highly concentrated virus solutions are prone to filter clogging if aggregation of viruses occurs or impurities attach to the viruses. Several filters were screened aiming to identify those which allow filtering highly concentrated stocks of LVVs of up to 1E + 9 transducing units mL−1, which corresponds to 4.5E + 12 particles mL−1. In addition, the effect of endonuclease treatment upstream of the purification process on filter performance was studied. In summary, three suitable filters were identified in a small‐scale study (<15 mL) with virus yields >80% and the process was successfully scaled‐up to a final scale of 100 mL LVV stock solution. Graphical and Lay Summary Lentiviral vectors for gene therapy are produced in bioreactors and subsequently purified and concentrated. A process to filter highly concentrated lentivirus solutions through pores only slightly larger than the lentiviruses was developed and scaled‐up. Thereby, this improves the safety profile of the process and ultimately patient safety.