Oncolytic virotherapy (drugs based on viruses which trigger cancer cell death and an immune response) have been approved for doctors to prescribe to patients for longer than most realise.
Back in 2003 Gendicine was approved by the State Food and Drug Administration of China (SFDA) for head and neck squamous cell carcinoma (HNSCC) . It is a replication-incompetent, recombinant, serotype 5 human adenovirus (Ad5) engineered to contain the human wild-type p53 tumor-suppressor gene. It could be argued that Gendicine is not in fact a “true” oncolytic virus as it is replication incompetent, however I include it here because in recent years it has been recognised that oncolytic virotherapies generate an immune reaction against the tumour. This can lead to tumour lysis indirectly and may be more important than direct viral lysis. Indeed Gendicine leads to tumour cell lysis.
In 2005 the SFDA of China approved a classic (replication competent) oncolytic virotherapy called Oncorine for HNSCC . Oncorine is an Ad5 with an E1B and E3 gene deletion. The development in the USA of a very similar virus called Onyx-15 was halted at the outset of a phase III trial due to a funding crisis. This funding crisis has resulted in a ten year lag behind China in the approval of an oncolytic virus.
In October 2015, the US food and drug administration (FDA) approved Imlygic, for the treatment of melanoma in patients with inoperable tumors . In Jan 2016 it was approved in Europe for some inoperable melanoma . Imlygic is a herpes simplex virus 1 (HSV-1) based oncolytic vector delivered via injection. It was generated from a fresh isolation of HSV-1 virus (JS1) and has a GM-CSF replacement of the two copies of the ICP34.5 gene which normally reverses the interferon induced phosphorylation of the α subunit of the eukaryotic initiation factor 2 (EIF2S1) . The interferon pathway is usually disrupted in cancer thus lending the vector specificity to cancer cells.
Although the first FDA approval has been a long time coming there are many oncolytic viruses now in the clinical pipeline with more approvals likely.
- Pearson, Sue, Hepeng Jia, and Keiko Kandachi. ‘China Approves First Gene Therapy’. Nature Biotechnology 22, no. 1 (January 2004): 3–4. doi:10.1038/nbt0104-3.
- Garber, Ken. ‘China Approves World’s First Oncolytic Virus Therapy For Cancer Treatment’. Journal of the National Cancer Institute 98, no. 5 (3 January 2006): 298–300. doi:10.1093/jnci/djj111.
- ‘FDA Approves Amgen’s Injected Immunotherapy for Melanoma’. Reuters, 27 October 2015. http://www.reuters.com/article/us-amgen-fda-idUSKCN0SL2YH20151027.
- Semedo, Daniela, and PhD. ‘Metastatic Melanoma Therapy, Imlygic, Now Available in EU’. Immuno-Oncology News, 7 January 2016. http://immuno-oncologynews.com/2016/01/07/metastatic-melanoma-therapy-imlygic-now-available-eu/.
- Liu BL, Robinson M, Han Z-Q, Branston RH, English C, Reay P, et al. ICP34.5 deleted herpes simplex virus with enhanced oncolytic, immune stimulating, and anti-tumour properties. Gene Ther 2003; 10:292–303. [PMID: 12595888]