A promising new virus therapy may help you live longer if you’re in the advanced stages of melanoma skin cancer. This treatment injects a modified version of the herpes virus directly into tumors to attack cancer cells.
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How does virus therapy work?
Plastic surgeon Brian Gastman, MD, Director of Melanoma Surgery at Cleveland Clinic, describes the virus as a mindless being that attacks cells in your body and replicates in order to make more viruses.
“Since a cell cannot hold all of these viruses, it bursts and releases more virus particles that infect other cells,” Dr. Gastman says.
Scientists have discovered that certain viruses, known as oncolytic viruses, like to infect tumor cells more than regular cells.
“Researchers wanted to take advantage of that phenomenon,” Dr. Gastman says. “If they could inject a controlled virus into a cell and replace some of the viral guts, it could force the body to mount an anti-tumor response.”
Researchers created an oncolytic virus treatment by modifying the herpes virus genetically. The treatment is known as talimogene laherparepvec or T-VEC. Essentially, it causes the tumor cells to self-destruct, Dr. Gastman says.
A powerful, new treatment
Researchers also found that, as the virus attempts to kill tumor cells, it also sends out danger signals to the rest of the body, triggering an immune response.
“It was tested in patients who were beyond surgeries and didn’t have many options left,” says Dr. Gastman. “For some patients, the tumor shrank significantly. It’s coming after the tumor in a different way.”
The more ways you can attack cancer, the less chance it can evolve and resist treatment. “This gets us even closer to that threshold where we can cure everybody someday,” he says.
Best patients for T-VEC therapy
Doctors offer T-VEC therapy for those with advanced melanoma who won’t benefit from surgery. They inject it directly into tumors in the skin, under the skin or within lymph nodes. They typically repeat the injections every two to three weeks until the tumor is no longer larger enough to inject., Dr. Gastman says.
They will not use the virus therapy alone, but typically combine it with immunotherapy, he says.
“There has been this explosion of immunotherapy where we give drugs to patients that bolster their immune system,” he says.
There are two classes of immunotherapies that are FDA-approved for melanoma. Doctors inject the virus into the tumor cells and give the patients one of these immune-boosting drugs through an IV.
Limiting side effects
Though they may not last long, you may see several possible side effects during T-VEC therapy — mostly flu-like symptoms such as chills, fever, nausea and fatigue.
“Most of these side effects will go away after a day or two,” Dr. Gastman says. “We medicate our patients to prevent as many of these side effects as possible.”
High hopes for the future
Several companies are now creating similar viruses and modifying the same virus in different ways. Many of these therapies are currently in the clinical trial phase.
“In the future we expect we can inject many tumors — regardless of location, even in the brain — with these types of drugs,” he says. “There are studies underway for neck, breast and lung cancers. Once those results come out, these drugs may spread vigorously to many cancer types. The sky is the limit.”