SP3-based host cell protein monitoring in AAV-based gene therapy products using LC-MS/MS.

Residual host cell proteins (HCPs) represent a critical quality attribute of biotherapeutic drug products. Workflows enabling reliable HCP detection in monoclonal antibodies and recombinant proteins have been developed, which facilitated process optimization to improve product stability and safety, and allowed setting of acceptance limits for HCP content. However, the detection of HCPs in gene therapy products such as adeno-associated viral (AAV) vectors has been limited. Here, the use of SP3 sample preparation followed by liquid chromatography-mass spectrometry (LC-MS) analysis for HCP profiling in various AAV samples is reported. Suitability of the workflow is demonstrated and provided data constitutes an important reference for future work aiming towards a knowledge-driven improvement of manufacturing conditions and characterization of AAV vector products.