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 a virus is injected into the tumor. When the viruses enter cancer cells, they make many 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.

What types of oncolytic virus therapy are available to treat cancer?

Currently, 2 types of oncolytic virus therapy are approved in the United States to treat cancer, both for melanoma of the skin:

• Talimogene laherparepvec (Imlygic) or T-VEC is approved to treat melanomas in the skin or lymph nodes that have come back after surgery and can't be removed.
• Vusolimogene oderparepvec (Tudriqev), formerly known as RP1, can be used to treat advanced melanomas that are no longer responding to a PD-1 checkpoint inhibitor. It is given along with the checkpoint inhibitor nivolumab.

These treatments are injected directly into one or more melanoma tumors, typically every 2 weeks. This method is called intralesional therapy.

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:

• Fever
• Chills
• Muscle or joint aches
• Pain at the injection site
• Fatigue

Other side effects are also possible. Your cancer care team will tell you what to watch for.

Your cancer care team will also 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.