Viral clearance for biopharmaceutical downstream processes

Viral clearance studies are mandated prior to entering clinical trials and for commercial launch of biopharmaceuticals. These studies are a key component of risk mitigation to reduce the potential for iatrogenic transmission of pathogenic viruses. This paper reviews regulatory guidance and practical strategies for designing viral clearance studies. Essential elements of a developmental phase-appropriate viral clearance package are detailed. These include scale-down model qualification, virus spike experiments and validation (clearance evaluation) of manufacturing process steps. Heuristics and learnings from available data are shared. Developments in this area including generic validation strategies, multiviral spiking strategies and use of newer model viruses for nonconventional substrates are also described. This review provides a framework for a comprehensive viral validation package for regulatory submissions.