Table 1.

Summary of the main modifications of the oncolytic viruses evaluated in the clinic.

Virus Family	Name	Modification: Effect
Adenovirus	ONYX-015; DNX-2401; DNX-2440	E1B-55K deletion: selects tumors with deficient p53 E1AΔ24: selects cells with E2F-Rb deregulation RGD-4C insertion: facilitates viral entry to cells expressing αvβ3- and αvβ5-integrin OX40L insertion: increases T cell-mediated immunity
Herpesvirus	HSV1716; G207; G47Δ; C134; M032; rQNestin34.5	ICP34.5 deletion: makes it unable to replicate in normal neuronal cells ICP6 deletion: makes it unable to replicate in normal neuronal cells ICP47 deletion: prevents evasion from immune recognition IL-12 expression: immunostimulatory molecule
Reovirus	Reolysin	None
NDV	NDV-HJU; MTH-68/H	Attenuated strain: tumor-specific
Poliovirus	PVSRIPO	IRES replacement: eliminates neuropathogenesis
Parvovirus	ParvOryx01,	None
Retrovirus	Toca 511	FCU1 insertion: encodes for an yCD enzyme able to locally convert the prodrug 5-FC to the drug 5-FU
Measles virus	MV-CEA; MV-NIS	Attenuated Edmonston strain: vaccine hCEA expression: to track the viral gene expression NIS expression: to track the viral gene expression and deliver radioactive iodine
Vaccinia virus	TG6002	J2R deletion: selects cells that express thymidine kinase I4L deletion: selects cells with ribonucleotide reductase subunits expression FCU1 insertion: converts the prodrug 5-FC to the drug 5-FU

Abbreviations: hCEA: human carcinoembryonic antigen, IL-12: interleukin 12, IRES: internal ribosomal entry site, NIS: human thyroidal sodium iodide symporter, NDV: Newcastle disease virus, RGD: arginyl-glycil-aspartic acid motif, yCD: yeast cytidine deaminase, 5-FC: 5-Fluorocytosine, and 5-FU; 5-Fluorouracil.