Biopharmaceutical Industry Practices for Sequence Variant Analyses of Recombinant Protein Therapeutics

The application of advanced methodologies such as next-generation sequencing (NGS) and mass spectrometry (MS) to the characterization of cell lines and recombinant proteins has enabled the highly sensitive detection of sequence variants (SVs). However, while these approaches can be leveraged to provide deep insight into product micro-heterogeneity caused by SVs, they are not used in a standardized manner across the industry. Currently, there is little clarity and consensus on the utilization, timing, and significance of SV findings. This white paper addresses the current practices, logistics, and strategies for the analysis of SVs using a bench-marking survey coordinated by the International Consortium for Innovation & Quality in Pharmaceutical Development (IQ) as well as a series of deliberations amongst a panel of experts assembled from across the biopharmaceutical industry. Discussion includes current industry experiences including approaches for detection and quantitation of SVs during cell-line and process development, risk assessments and regulatory feedback. While SVs are a potential issue for all recombinant protein therapeutics, the scope of this discussion will be limited to SVs produced in mammalian cells. Ultimately, it is our hope that the findings from the survey and deliberations of the committee are useful to decision makers in industry and positions them to respond to findings of SVs in recombinant proteins that are destined for clinical or commercial use in a strategic manner.