Join us at BPI’s hybrid conference in Boston, MA from September 20-30, as part of Biotech Week Boston. This year’s agenda includes nine tracks, spanning all phases of bioprocessing for biologics, and cell and gene therapies. Various tracks include:
- Cell culture and upstream processing
- Manufacturing strategy
- Increasing speed from gene to market
Mass Spectrometry Support for HCP ELISA in AAV Gene Therapy
Residual Host Cell Proteins (HCP) are inevitable impurities in any biopharmaceutical product and a critical quality attribute relevant to the safety of gene therapy products. AAV viral vectors are typically manufactured using human cell lines like HEK293, which present a potentially complex proteome background. Contrasting with recombinant proteins purified from cell culture supernatant, the harvest of viral vectors typically relies on cell lysis, meaning the entire proteome may contribute to the HCP load presented to downstream purification processes where purification steps may also be limited in number, impacting the overall capacity to separate the virus product from other protein impurities. Adding to any technical challenges, gene therapy programs are often intended for severe indications, and more likely to be placed on an accelerated development pathway. This time pressure conflicts with the timeline required to develop a product-specific immunoassay, so the use of commercially available generic HCP detection ELISA kits is common practice from early-stage through late-stage viral vector product development. Quantification of HCPs by LC-MS is an unbiased orthogonal approach to ELISA detection wherein peptide standards can be spiked into test articles at defined concentrations providing a quantitative readout of HCP content while also providing for identification of the individual proteins detected. LC-MS is an advantageous strategy to use to report on commercial ELISA kit coverage, guiding refinement of AAV purification strategies on a faster timescale than is possible by product-specific ELISA development.