AT Europe 2019

March 15, 2019 – 12:00 – 12:30

Identification and tracking of problematic host cell proteins through downstream bioprocessing

Speaker: Jonathan Bones - NIBRT - The National Institute for Bioprocessing Research and Training, Dublin, Ireland

A key challenge during biopharmaceutical manufacturing is the removal of cellular contaminants that arise from host cells. Host cellular proteins and DNA if present in the therapeutic material pose an immunological risk to patients and must be removed. Recent years have witnessed dramatic improvements in the performance of manufacturing cell lines with regard to cell density, productivity and improved titre. However, the quantity and repertoire of complex proteins produced by the host cell during monoclonal antibody (mAb) production has generated a bottleneck in downstream bioprocessing. Low parts per million (ppm) levels of host cell proteins (HCPs) must be achieved at the downstream purification process stage to generate an end product suitable for use in humans.

Here, we describe a study optimizing the clarification process for removal of problematic HCPs during downstream bioprocessing of mAbs. Total host cell protein and host cell DNA were determined using the ProteinSEQ and ResDNASEQ assay kits from Thermo Fisher Scientific to monitor the clearance of HCPs and host cell DNA (HCDNA) during downstream processing. Additionally, advanced LC-MS based proteomic methods were used to track and identify known ‘problematic’ HCPs through a multi-cycle Protein A purification process. Complete removal of histone proteins was observed, along with an average total HCP reduction of 38-fold and an average reduction of 2.3 log in HCDNA concentration. Through the above analyses, we demonstrate that the optimized method has the potential to increase Protein A resin lifetime and reduce the number of subsequent polishing chromatographic steps needed to remove HCPs that have a tendency to co-purify with mAb products.