Oncolytic Virus Therapy and Its Side Effects
Some viruses can be specially changed to infect and kill cancer cells while leaving healthy cells alone. These viruses can also activate the immune system, helping it recognize and attack other cancer cells. Oncolytic virus therapy is currently used to treat melanoma.
What is oncolytic virus therapy?
Oncolytic virus therapy, sometimes just called virus therapy, uses viruses that have been changed in a lab to destroy cancer cells. A genetically modified version of the virus is injected into the tumor. When the viruses enter cancer cells, they make copies of themselves. As a result, the cancer cells burst and die.
As the cancer cells die, they release proteins that trigger your immune system to target any other cancer cells in your body with the same proteins as the dead cancer cells. The virus doesn’t enter healthy cells.
What types of oncolytic virus therapy are available to treat cancer?
Currently, one type of oncolytic virus therapy is approved in the United States to treat cancer:
Talimogene laherparepvec (Imlygic) or T-VEC. This oncolytic virus therapy is approved to treat advanced melanoma that cannot be treated with surgery. It’s used most often for people who cannot or choose not to receive any other recommended treatments. T-VEC is a modified version of the herpes simplex virus, which causes cold sores. It is injected directly into one or more melanoma tumors. (This method is called intralesional therapy.) This treatment can sometimes shrink these tumors, and it might also shrink tumors in other parts of the body.
Side effects of oncolytic viruses
Side effects of oncolytic viruses differ from person to person and depend on the type of oncolytic virus used. Some common side effects include:
Your cancer care team will watch you closely during treatment and will check you often. Side effects can and should be treated as early as possible. It’s important to tell your cancer care team about any changes in how you feel or anything you notice that’s new or unusual. Tell them right away so they can treat any problems and try to keep them from getting worse.
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- References
Developed by the 91黑料不打烊 medical and editorial content team with medical review and contribution by the American Society of Clinical Oncology (ASCO).
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Last Revised: July 7, 2025
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