The Importance of Viral Clearance and Characterization in Gene Therapy Products

It is a regulatory requirement (ICH Q5A Revision 2) to demonstrate the viral safety of biotechnology products derived from in vitro cell culture, including viral vector-derived products like recombinant Adeno-associated viruses, used as a delivery medium for gene therapy products. Viral clearance in gene therapy products poses different challenges from the other non-viral biotechnology products in terms of viral removal strategies. In this webinar, we will present a case study with a clinically relevant AAV8 downstream process:

1. The rationale of the study design is the choice of virus panel, surrogate, and unit operation for demonstrating viral clearance.
2. Present the clearance achieved in a scaled-down model of the process

Presented by Ya-Chen Chang, Principal Scientist, downstream process development team at Regenxbio

Ya-chen Chang has been working in downstream process development and tech transfer for 17 years. She is currently a principal scientist in the downstream process development team at Regenxbio, working on AAV downstream processes spanning from the early clinical phase to late-stage development. Prior to Regenxbio, Ya-Chen gained experience in developing downstream processes and tech transfer for the monoclonal antibody, virus-like particle, nanoparticle, and plasmid vaccines at the Vaccine Production Program Laboratory of the VRC/NIAID/NIH for Clinical Phase 1/2. Ms. Chang received a Master’s in Biotechnology and a BS in Chemical Engineering from Northwestern University in Evanston, IL.

Akunna Iheanacho, Ph.D. Chief Scientific Officer at Texcell – North America, Inc

Akunna Iheanacho, Ph.D. is the Chief Scientific Officer at Texcell – North America, Inc. where she provides technical and scientific direction for all programs and business units in addition to providing oversight for novel assay development, virus purification efforts, viral safety testing, and custom cell culture projects. She is a subject matter expert with broad biotechnology experience and expertise in areas that include biopharmaceutical purification and process development for large-scale cGMP manufacture of AAV gene therapies, vaccines, and other biologics. Prior to joining Texcell, Dr. Iheanacho was a Senior Scientist at Paragon Bioservices (now Catalent), where she transitioned projects from basic science discovery to cGMP-ready processes by establishing critical process parameters and quality attributes for biologics.

Dr. Iheanacho’s graduate work utilized mouse models, molecular endocrinology, and structural biology to study signaling pathways in cancer metabolism, fat metabolism, and type 2 diabetes. In her structural and functional characterization of a diverse set of proteins, she employed biochemical and biophysical techniques as well as molecular biology. Dr. Iheanacho received her Ph.D. in Cellular and Molecular Physiology from Johns Hopkins University School of Medicine, M.S. in Chemistry from the University of Virginia, and B.S. in Biology from Oakwood University in Huntsville, AL.

Katelyn Pritchard, Viral Clearance Study Director at Texcell – North America, Inc

Katelyn Pritchard is a Viral Clearance Study Director with Texcell North America where she oversees the design, planning, and execution of Viral Clearance studies for a variety of Biopharmaceuticals. Katelyn joined Texcell in 2018 and has participated in Viral Clearance studies at a variety of levels including virus assays and scaled down process step execution prior to her role as Study Director. She has contributed to the validation of various virus assays including TCID50 infectivity assays, Plaque forming infectivity assays, and quantitative polymerase chain reaction assays. She is a subject matter expert in Texcell’s virus assays as they relate to viral clearance studies. Katelyn received her B.S. in Biological Sciences from North Carolina State University

High Resolution Chromatography for AAV Polishing as key Virus Removal Step

Viral vectors undergo regulatory requirements for viral safety (ICH Q5A Revision 2), similar to any other product derived from human or animal cell line culture. One of the widely used vectors in gene therapy is the Adeno-associated virus, with currently more than 350 ongoing clinical trials. Similar characteristics of full AAV vector and potentially adventitious virus contaminants represent a unique challenge for efficient virus removal strategy, very similar to ensuring efficient separation of empty and partial particles, co-produced during the upstream process.

Such separation requires very high-resolution chromatography media and scale-to-scale reproducibility within just a few percent. To address the above-mentioned needs Sartorius BIA Separations developed new CIMmultus HR line (HR stands for High Reproducibility) columns with better resolution and narrower acceptance criteria. These columns allow for batch-to-batch and scale-to-scale reproducibility within just 3% of the AAV8 empty capsid isoconductivity elution and permit step gradient elution using the same buffer strength at any scale. Removal of empty capsids in two orders of magnitude should be possible at any scale, as well as efficient several log removals of model viruses.

Presented by Maja Leskovec, Head of Process Development Viruses at Sartorius BIA Separations

Maja is heading Process development Viruses at Sartorius BIA Separations. She has more 10 years’ experience in the field of downstream development, working in laboratory as well as leading development projects for clients, resulting in processes for pre-clinical and clinical applications. She co-developed various DSP processes, including AAV for AveXis/Novartis. One of the key focuses of her group is holistic view on the viral production, combining knowledge from upstream, downstream and analytics.

Sponsored by Texcell and Sartorius

About Texcell

One of the services offered at the Texcell facility is GLP-compliant viral clearance testing that is performed to support biopharma/biotech regulatory applications submitted to the FDA and other regulatory authorities. As a global organization, Texcell has conducted over 10,000 viral clearance evaluations worldwide.  

Most viral clearance studies are performed in collaboration with large to medium-sized biotherapeutic industry leaders and government contracts. The data generated by Texcell has been used to support IND/NDA and BLA/MA filings.  Our knowledgeable scientific staff has performed viral clearance evaluations for a range of purification steps, including chromatography, filtration, and inactivation methods, as well as evaluations of column age and sanitization/cleaning efficacy. In addition, Texcell provides custom cell culture services, from clonal selection and cell line expansion to cGMP cell banking and all associated viral safety testing.

About Sartorius

Sartorius BIA Separations develops and manufactures market-leading CIM® monolithic chromatographic columns for the purification and analysis of large biomolecules, such as viruses, plasmids, and mRNA, which are applied in cell and gene therapies. The company’s Cornerstone® Biomanufacturing Development Services are the result of more than 25 years of hands-on experience with the most challenging biopharmaceutical products and offer a comprehensive approach of integrated process development solutions and novel technology designed to improve the robustness and yield of large biomolecules production while improving the safety of therapeutic products. Sartorius BIA’s technology for manufacturing-scale purification is already used in the production of the first commercialized advanced therapeutics; the company also has a keen presence with novel drug candidates in the clinical pipeline.