Clinical Considerations for Oncolytic Viral Therapies: A Regulatory Perspective
This approval represents an apex of intensive scientific and clinical research on OVT.2 Oncolytic viruses (OVs) are characterized by the potential to kill cancer cells while sparing normal cells. These agents include diverse RNA and DNA viruses, which can target a variety of tumor types. In some cases, genetic modifications have been designed to improve the potential efficacy or safety of these viruses. For example, an oncolytic virus can be modified to express a transgene that has direct cytotoxic activity or enhances the immune response. In Imlygic, the attenuated herpes simplex virus type 1 (HSV‐1) is genetically modified to express human granulocyte‐macrophage colony‐stimulating factor (huGM‐CSF).3 These OVs can be administered locally (e.g., intratumorally) or systemically by intravenous infusion.
Still, many regulatory challenges exist in the development of OVT, including, but not limited to, challenges in clinical trial design and manufacturing of OVs. For example, it is essential to have a manufacturing process, along with associated test methods and control measures, that is capable of yielding an OV product with consistent quality characteristics. This commentary focuses on some clinical considerations that are unique to OVT.