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Some members of MIT's Consortium on Adventitious Agent Contamination in Biomanufacturing (CAACB) previously published content on the ″Quality Risk Management in the Context of Viral Contamination″ which described tools, procedures, and methodologies for assessing and managing the risk of a potential virus contamination in cell culture processes. To address the growing industry interest in moving manufacturing towards open ballrooms with functionally closed systems and to demonstrate how the ideas of risk management can be leveraged to perform a risk assessment, CAACB conducted a case study exercise of these new manufacturing modalities. In the case study exercise, a cross-functional team comprised of personnel from many of CAACB's industry membership collaboratively assessed the risks of viral cross-contamination between a human and non-human host cell system in an open manufacturing facility. This open manufacturing facility had no walls to provide architectural separation of two processes occurring simultaneously, specifically a recombinant protein perfusion cell culture process using the human cell line, HEK-293 (Process 1) and a downstream post-viral filtration unit operation (Process 2) of a recombinant protein produced in CHO cells. This viral risk assessment focused on cross-contamination of the Process 2 filtration unit operation after the Process 1 perfusion bioreactor was contaminated with a virus that went undetected. The workflow for quality risk management that is recommended by the International Council for Harmonisation (ICH) was followed, which included identifying and mapping the manufacturing process, defining the risk question, risk evaluation and risk control. The case study includes a completed Failure Mode and Effects Analysis (FMEA) to provide descriptions of the specific risks and corresponding recommended risk reduction actions.

The Consortium on Adventitious Agent Contamination in Biomanufacturing (CAACB) collected historical data from 20 biopharmaceutical industry members on their experience with the in vivo adventitious virus test, the in vitro virus test, and the use of next generation sequencing (NGS) for viral safety. Over the past 20 years, only three positive in vivo adventitious virus test results were reported, and all were also detected in another concurrent assay. In more than three cases, data collected as a part of this study also found that the in vivo adventitious virus test had given a negative result for a sample that was later found to contain virus. Additionally, the in vivo adventitious virus test had experienced at least 21 false positives and had to be repeated an additional 21 times all while using more than 84,000 animals. These data support the consideration and need for alternative broad spectrum viral detection tests that are faster, more sensitive, more accurate, more specific, and more humane. NGS is one technology that may meet this need. Eighty one percent of survey respondents are either already actively using or exploring the use of NGS for viral safety. The risks and challenges of replacing in vivo adventitious virus testing with NGS are discussed. It is proposed to update the overall virus safety program for new biopharmaceutical products by replacing in vivo adventitious virus testing approaches with modern methodologies, such as NGS, that maintain or even improve the final safety of the product.

Appropriate segregation within manufacturing facilities is required by regulators and utilized by manufacturers to ensure that the final product has not been contaminated with 1) adventitious viruses, 2) another pre-/ post-viral clearance fraction of the same product, or 3) with another product processed in the same facility. However, there is not consensus on what constitutes appropriate facility segregation to minimize these risks. In part, this is due to the fact that a wide variety of manufacturing facilities and operational practices exist, including single and multi-product manufacturing, using traditional segregation strategies with separate rooms for specific operations that may use stainless steel or disposable equipment to more modern ballroom style operation that use mostly disposable equipment (i.e. pre- and post-viral clearance manufacturing operations are not physically segregated by walls). Further, there is a lack of consensus around basic definitions and approaches related to facility segregation. For example, given that several unit operations provide assurance of virus clearance during downstream processing, how does one define pre- and post-viral clearance and at which point(s) should a viral segregation barrier be introduced? What is a “functionally closed” system? How can interventions be conducted so that the system remains “functionally closed”? How can “functionally closed” systems be used to adequately isolate a product stream and ensure its safety? To address these issues, the member companies of the Consortium on Adventitious Agent Contamination in Biomanufacturing (CAACB) have conducted a facility segregation project with the following goals: define “pre- and post-viral clearance zones” and “pre- and post-viral clearance materials”; define “functionally closed” manufacturing systems; and identify an array of facility segregation approaches that are used for the safe and effective production of recombinant biologics as well as plasma products. This article reflects the current thinking from this collaborative endeavor.

Recombinant protein therapeutics, vaccines, and plasma products have a long record of safety. However, the use of cell culture to produce recombinant proteins is still susceptible to contamination with viruses. These contaminations cost millions of dollars to recover from, can lead to patients not receiving therapies, and are very rare, which makes learning from past events difficult. A consortium of biotech companies, together with the Massachusetts Institute of Technology, has convened to collect data on these events. This industry-wide study provides insights into the most common viral contaminants, the source of those contaminants, the cell lines affected, corrective actions, as well as the impact of such events. These results have implications for the safe and effective production of not just current products, but also emerging cell and gene therapies which have shown much therapeutic promise.