[Important aspects of virus safety of advanced therapy medicinal products]

Virus safety of advanced therapy medicinal products is a particular challenge. These products may consist of whole cells and the manufacture of these is performed using various human or animal-derived starting materials and reagents. Therefore, extensive testing of donors and of established cell banks is required. Furthermore, the virus safety of reagents such as bovine sera, porcine trypsin, and growth factors needs to be considered. Whenever possible, manufacturing steps for inactivation or removal of viruses should be introduced. However, it is not possible to introduce such steps for cell-based medicinal products as the activity and viability of cells will be compromised. Only in the production of small and stable non-enveloped viral gene vectors is it conceivable to implement steps to selectively inactivate or remove potential contaminating enveloped viruses.