From Adherent to Suspension: De-risking the AAV Scalability Pathway

The transition from preclinical research to clinical manufacturing for advanced therapeutics and complex biologics presents a common inflection point for AAV vector programs. Applying proven intelligence in vector production to establish a scalable process early is necessary to navigate this shift and maintain program timelines. The initial choice of production platform has significant downstream implications for clinical readiness.

Many programs originate using adherent cell culture platforms. This approach is well-suited for producing the vector quantities needed for initial discovery and early preclinical toxicology evaluations and has been strongly established in the research and discovery community. The physical surface area limitations of adherent systems, however, create a ceiling on volumetric productivity. This poses a bottleneck when larger quantities are required for IND-enabling studies and clinical trials.

The shift to suspension-based culture in stirred-tank bioreactors is often imperative to achieving commercial scale. This transition requires a dedicated process development effort to adapt cell lines from adherent to suspension, optimize transfection parameters for a three-dimensional environment and improve purification methods to provide increased clearance of impurities from high-density suspension processes. This work enables the production of clinically validated capsids like AAV8 and AAV9 at the scale required for systemic administration in high dose applications.

A forward-looking CMC strategy anticipates these scaling challenges by addressing several key domains in parallel:

• Plasmid Supply: Securing a reliable source of high-quality plasmid DNA is a prerequisite for any scalable production run.
• Platform Transition: A deliberate plan to move from adherent to suspension platforms, backed by comparative analytical data and an approach which has been vetted by the relevant regulatory authorities.
• Analytical Readiness: Developing and qualifying robust analytical methods to ensure product consistency, from vector genome titer and aggregation assays to cell-based potency assays.
• Process Characterization: Defining process parameters that ensure batch-to-batch consistency and product quality.

This integrated approach is built on the deep experience of our scientific leadership. It is this team’s legacy of expertise, including a 100% successful IND rate for client programs since 2019, that forms the foundation of Franklin Biolabs, launched in 2024. By addressing scalability as an integrated component of preclinical development, therapeutic developers can accelerate their path to the clinic.