Designing and building oncolytic viruses

Maroun, Justin; Muñoz-Alía, Miguel; Ammayappan, Arun; Schulze, Autumn; Peng, Kah-Whye; Russell, Stephen

Immediately following IT delivery, small levels of virus can be detected in the blood from leakage through injured tumor vasculature [75] , but that small amount of virus is quickly cleared from the system. Also, virus that has been injected into a tumor is frequently extruded immediately from the injection track once the syringe is removed, especially in smaller higher pressure tumors. However, systemic viral spread can occur following IT administration if the initially exposed tumor cells are capable of amplifying the input virus and releasing progeny into the bloodstream. Such secondary viremia may not peak until several days after IT virus delivery and, with currently used OVs, is often not detected. Secondary viremia, when it occurs, more closely mimics the natural propagation of a viral infection from the site of inoculation to more distant target organs.