Table 1.

Main groups of oncolytic viruses classified by taxonomy families.

Virus family	Genome type	Genome size (Kb)	Replication site	Capsid	Mechanism of selectivity	Armed	Viruses in clinical development (or approved when indicated)
Retroviruses:Murine leukemia virus	dsRNA (requires integration in cell genome as DNA)	8	Nucleus	Enveloped	Requires cell division to enter the nucleus	Transgenes	Toca-511
Picornaviruses: Coxsackievirus A21 ECHO-7 Seneca virus Poliovirus	ssRNA	7.5	Cytoplasm	Naked	IFN sensitive (IFN inhibits protein translation and virus replication but in tumor cells this protein translational block is impaired) Receptor tropism: CVA21 infects by ICAM-1 as primary receptor and DAF as coreceptor.	miRNAs Only small insertions (300bp)	CAVATAK Rigvir (Approved) SVV-001 PVSRIPO
Rhabdoviruses: Vesicular stomatitis virus (VSV) Maraba	ssRNA	15	Cytoplasm	Enveloped	IFN sensitive M protein mutations increase IFN sensitivity	Transgenes	VSV-IFNβ VSV-IFNβ-NIS Maraba MG1-MAGEA3.
Paramyxoviruses: Meales Newcastle disease virus (avian virus)	ssRNA	16-20	Cytoplasm	Enveloped	IFN sensitive Edmonton Measles strain infects via CD46 and SLAMs found in B and T lymphocytes. Appropriate for myeloma.	Transgenes	MV-CEA MV-NIS NDV PV701 NDV MEDI5395
Reoviruses: Mammalian orthoreovirus Type 3 Dearing	dsRNA (in fragments or segments)	22-27	Cytoplasm	Naked	IFN sensitive	No	Reolysin
Parvoviruses:H1 autonomous rat parvovirus	ssDNA	5	Nucleus	Naked	Unknown (active metabolic and regulatory pathways allow replication of this rat virus in human tumor cells).	No	H1-PV Parvoryx
Adenoviruses	dsDNA	36	Nucleus	naked	RB pathway if E1a binding site to pRB is deleted Control of gene expression with tumor selective promoters.	Transgenes	H101 (approved) CG0070 LOAd703 DNX-2401 Telomelysin ColoAd1 ONCOS-102 VCN-01
Herpesviruses	dsDNA	150	Nucleus	Enveloped	Becomes IFN sensitive if viral gamma 34.5 gene is deleted. Depends in high nucleotide metabolism if viral Thymidine Kinase gene is deleted. Control of gene expression with tumor selective promoters.	Transgenes	Tvec (Imlygic) (Approved) HSV1716 G207 RP1
Poxviruses: Vaccinia Virus (VV) Mixoma Virus (of rabbits)	dsDNA	190	Cytoplasm	Enveloped	Becomes IFN sensitive if viral B18R gene is deleted. Depends in high nucleotide metabolism if viral Thymidine Kinase or Ribonucleotide reductase genes are deleted. Depends on EGF-R pathway if VGF gene is deleted.	Transgenes	JX-594 TG6002 GL-ONC1 GLV-1h68

Key parameters for oncolysis are shown. Some examples of viruses in clinical development are included for each virus family. Top RNA viruses, bottom DNA viruses. Ordered by genome size.