Viral contamination is an inherent risk during the manufacture of therapeutic products such as antibodies, vaccines, viral vectors, and plasma derivates. Whether introduced endogenously from raw materials or exogenously through manufacturing operations, unmitigated viral contaminations can lead to serious health implications and plant shutdowns. Therefore, international regulatory agencies require sponsoring companies to validate the “viral clearance efficacy” of their individual downstream purification process steps before clinical trials or commercial approval [1].
Viral clearance validation is assessed through small-scale “spiking studies,” where model mammalian viruses (e.g., Minute Virus of Mice [MVM], or Xenotropic Murine Leukemia Virus [XMuLV]) are introduced into in-process material that is then processed through a purification technique (e.g., chromatography, nanofiltration, and low pH). Viral quantity pre/post-processing is determined through an infectivity (e.g., TCID50) or qPCR assay and the log reduction value (LRV) is calculated.
Spiking studies require specialized contract research organizations (CRO’s) and trained personnel resulting in high costs and complex logistics. These hurdles deter companies from analyzing viral clearance during the years of small-scale process development. Instead, companies spend considerable resources optimizing manufacturing processes before gaining any knowledge of their viral clearance efficacy. Unfortunately, this increases the risk of validation failure, forcing companies to invest additional time and money redeveloping process steps, which in turn, could postpone regulatory approvals and delay patients’ timely access to therapies.
To help de-risk your downstream purification process and assess viral clearance early in process development, Cygnus provides a unique solution that enables viral clearance prediction early in downstream purification development. Now, through the use of Cygnus’s BSL-1 compatible viral clearance kits, you can easily and economically quantify viral clearance for downstream process steps in your own lab, on your own timeline.
In January 2024, global regulatory agencies (including the FDA as part of the ICH) published the revised Q5A(R2) guidelines which govern the biotechnology industry on the topic of viral safety and evaluation. This document provides an update to the regulatory stance on viral safety and addresses many of the technological advancements that have occurred since the previous 1999 version, including viral clearance considerations for: continuous processing, cell/gene therapy products and the use of “Prior Knowledge”.
Cygnus Technologies, through the MockV® product line, offers solutions which ease the accumulation of viral clearance data. Through this approach, companies can increase their process knowledge, leading to better justifications in support of “Prior Knowledge”. Supplementing a company’s existing prior knowledge with MockV® derived clearance data could effectively reduce the scope and/or need of conducting process-specific live viral validation spiking studies.
On the topic of CHO-endogenous RVLP, the document states that “For CHO cell-derived products, CHO-derived endogenous virus particles [RVLP] can also be used for viral clearance experiments.” In practical terms, this means that RVLP can be used to validate the retoriviral clearance efficacy of downstream process steps.
[1] Q5A(R2) Viral Safety Evaluation of Biotechnology Products Derived from Cell Lines of Human or Animal Origin, Jan 2024
Cygnus Technologies offers the MockV™ MVM Kit, as a BSL-1 compatible viral clearance prediction tool. This kit utilizes non-infectious surrogates to perform quantitative clearance analysis, enabling benchtop scientists to easily and economically quantify viral clearance in industrial processes gaining actionable insights into your process early in downstream purification development.
Cygnus’ MockV® RVLP Kit provides a highly purified and concentrated BSL-1 compatible stock solution of non-infectious Retrovirus-like Particles (RVLP) along with the necessary reagents for accurate and reliable RVLP quantification. RVLP is an actual non-infectious retrovirus-like contaminant generated during CHO production. In the early 1990’s, global regulatory agencies such as the FDA realized the prevalence of this particle and became concerned about the retroviral safety of CHO-derived biopharmaceuticals. Since then, the biopharmaceutical industry has relied on CRO’s to propagate XMuLV as a model retrovirus to demonstrate effective clearance. With the availability of the MockV® RVLP Kit, biopharmaceutical companies can now independently assess the removal of the original retroviral particle of regulatory concern, derived directly from CHO cells.
