Critical challenges and advances in recombinant adeno‐associated virus (rAAV) biomanufacturing

Abstract

Gene therapy is a promising therapeutic approach for genetic and acquired diseases nowadays. Among DNA delivery vectors, recombinant adeno‐associated virus (rAAV) is one of the most effective and safest vectors used in commercial drugs and clinical trials. However, the current yield of rAAV biomanufacturing lags behind the necessary dosages for clinical and commercial use, which embodies a concentrated reflection of low productivity of rAAV from host cells, difficult scalability of the rAAV‐producing bioprocess, and high levels of impurities materialized during production. Those issues directly impact the price of gene therapy medicine in the market, limiting most patients’ access to gene therapy. In this context, the current practices and several critical challenges associated with rAAV gene therapy bioprocesses are reviewed, followed by a discussion of recent advances in rAAV‐mediated gene therapy and other therapeutic biological fields that could improve biomanufacturing if these advances are integrated effectively into the current systems. This review aims to provide the current state‐of‐the‐art technology and perspectives to enhance the productivity of rAAV while reducing impurities during production of rAAV.

Manufacturing Cell and Gene Therapies: Challenges in Clinical Translation

“…Transfection conditions must be optimized to maximize AAV and LV production. Although the use of stable producer cell lines may serve clinically beneficial purposes, several points must be considered during manufacturing to facilitate clinical translation, such as contamination with helper viruses or cytotoxicity induced by vector components required for AAV production [ 41 ]. The purification process is another critical step in LV manufacturing because impurities (such as residual DNA, HEK293T cell proteins, medium components, and transfection reagents) can generate unwanted inflammatory responses.…”

Basic Principles of RNA Interference: Nucleic Acid Types and In Vitro Intracellular Delivery Methods

“…Because they have low pathogenicity and immunotoxicity, a high safety profile in clinical trials, long-lasting transgene expression, and a simple genome that is easy to be modified, AAV are promising candidates for in vivo drug delivery [ 245 , 246 , 247 ]. However, AAV are dependent parvoviruses as their replication is dependent on other viruses [ 248 ]. Despite intensive research on stable production lines in recent decades, the production of high quantities of AAV is very time-consuming and costly [ 248 ].…”

“…However, AAV are dependent parvoviruses as their replication is dependent on other viruses [ 248 ]. Despite intensive research on stable production lines in recent decades, the production of high quantities of AAV is very time-consuming and costly [ 248 ]. In addition, AAV can cause damage to insertion sites and have limited capacity for transgene cargo [ 249 , 250 ].…”

Advanced cell technologies: Making protein, cell, and gene therapies a reality

“…The genes and pathways identified will inform the path forward for cell and process engineering toward improved rAAV2 production. Finally, Fu et al (2023) review the advances made in rAAV bioproduction as well as the challenges ahead in making these therapeutics accessible. Lentivirus (LV) are another important viral vector used in gene and cell therapies for which large-scale production remains a major challenge.…”