Accurate vector copy number (VCN) determination
in gene-modified cellular products by coupling
ddPCR results and TLA-based data
Recorded Thursday 2 March 2023
Retroviral and lentiviral vectors are commonly used to genetically engineer T cells due to their high rates of transduction and long-term stable transgene expression. Since these tools can permanently integrate into the host cell’s DNA, thorough QC of their genetic outcomes becomes an unalienable task to ensure safety, efficacy, and consistency. To this end, accurate measurement of vector copy number (VCN) per cell represents an essential parameter for product characterization during ATMP manufacturing.
Given that the risk of oncogenesis increases with higher vector copy number (VCN) per cell, the U.S. FDA recommends limiting VCN to less than 5 copies per genome. As a result, this criterion has generated great interest among manufacturers to maintain copy numbers within a safe yet effective range. For this, droplet digital PCR (ddPCR) has proven to be an accurate method to precisely quantify the number of vector copies integrated per cell towards assessing the therapeutic window of integrative vector in engineered immune cells.
In this webinar, we present data from our recently completed National Institute of Standards and Technology (NIST) Genome Editing consortium project, which aimed to determine VCN in 5 transgenic human cell lines.
Learn how ddPCR yielded concordant results with our TLA data, thereby rending the application of ddPCR assays in conjunction with our proprietary TLA-based services an elegant approach to validate VCN in gene-modified cellular products and clinical samples.