468. Efficient Strategies To Deliver Reliable and High Quality Lentiviral Vector Biomanufacturing for Early Phase Clinical Trials By Optimization of Process and Regulatory Parameters
Authors: Chi-Lin Lee, Geoff Symonds, Louis Breton, Jeffrey S. Bartlett
Journal: Molecular Therapy (2015)

Lentiviral vectors (LVs) are important tools for gene transfer due to their efficiency and ability to stably transduce both dividing and non-dividing cells. As a result, investigators are using them as gene delivery vehicles in a wide variety of clinical applications. Nevertheless, large-scale clinical production using current good manufacturing practice (cGMP) methods comes with a set of challenges that must be considered as more clinical trials using lentiviral vectors receive regulatory approval. One important consideration in designing cGMP-compatible processes is the need to integrate regulatory considerations into manufacturing processes that are capable of producing consistent lentivirus for multiple cGMP productions. The vast majority of lentiviral vectors being used clinically have been produced by transient transfection, however, transient transfection based production is clearly labor intensive and subject to varivation. For this reason, several stable packaging cell line systems have recently been developed. While the use of these cell lines for the biomanufacturing of LV is particularly attractive for both scalability and consistency, development of such lines is time consuming and the regulatory pathway for the cGMP use of these lines has not been firmly established. With a mind toward the development of a reliable, high quality, cGMP-compliant biomanufacturing process for the clinical production of self-inactivating lentiviral vectors (SIN-LVs) we have established the CytegrityTM stable cell line system, based on the GPRG packaging cell line. Here we sought to define key regulatory parameters to facilitate cGMP production and regulatory approval using this system. This presented a number of challenges from the establishment and tracking of clonally derived cell lines, to definition and integration of quality testing requirements, to variable responses to process operating parameters. To address these challenges, we developed approaches to optimize and facilitate stable cell line generation and selection in the context of a clear regulatory pathway for quality testing and regulatory approval. Furthermore, we established processes for material and derivative tracking allowing concurrent report generation and bioproduction assessments. Finally, we have developed mechanisms for the integration of producer cell line development, characterization, and regulatory filing with translation to at-scale cGMP-compliant bioproduction. By optimizing both regulatory and upstream process parameters, we have developed a system that allows for extensive cGMP-compliant scale-up. This "Toolbox" strategy targeting cell line generation and process conditions has allowed us to achieve desired SIN-LV productivity and quality across multiples scales and utilizing numerous different closed bioproduction systems, not only allowing production of the quantities of lentivirus vector required for Phase I and II clinical trials, but paving the way for future commercialization.