Known for cold sores and misery, herpes is now being used as a weapon against melanoma – the latest example of turning one bane of humanity against another by using viruses to target cancer.
In a study involving 436 late-stage melanoma patients at 64 centers around the globe, patients were injected with a genetically modified version of the herpes simplex virus known as T-VEC. Sixteen percent saw a significant decrease in tumor sizes within the first year, and the improvement lasted for at least six months. Only 2% of patients who didn’t get T-VEC experienced such improvement.
And researchers expect the treatment to yield even better results when combined with another type of immunotherapy, which uses the body’s own immune system to fight cancer.
“It appears for many patients that (T-VEC) gives long-term remission and in some cases, cure,” says inventor Robert Coffin, a co-author on the study, which appears in the current issue of the Journal of Clinical Oncology. “Quite a number of people in that study got a complete response; all their disease went away … I’m a great believer in the concept of using viruses to treat cancer.”
Over the years, scientists have explored modifying various viruses, including measles and polio, to combat several types of cancer, including brain tumors and breast cancer. A 2013 review concluded that cancer-fighting viruses armed with genes that stimulate the immune system “are potent therapeutic cancer vaccines.” T-VEC and other treatments made from altered viruses will be discussed at the annual meeting of theAmerican Society of Clinical Oncology, which continues through Tuesday in Chicago.
T-VEC, a product of California-based biotechnology company Amgen, is made by removing the gene that causes herpes from the virus and inserting a different gene that revs up the immune system, says researcher Jason Chesney of the University of Louisville, a co-author on the study. The virus enters cancer cells and “blows them up,” he says, at the same time stimulating the body to fight the cancer.
The most common side effects experienced in the study were minor issues such as fatigue, chills and nausea.
Shari Wells, 56, of Ashland, Ky., entered the clinical trial in 2010 with stage 4, metastatic melanoma that began as a mole on her left leg. She vividly recalls sitting with doctors at University of Louisville’s James Graham Brown Cancer Center and learning that her melanoma was so dangerous and advanced that she likely had less than six months to live.
But after more than two years of treatment with T-VEC, she went into remission, and has had no problems since. “It saved my life,” she says. “I was never so thankful in my whole life than for that medicine. Without it, I would be dead.”
Researchers and Amgen have high hopes for T-VEC. Amgen acquired the company Coffin founded, Massachusetts-based BioVex, in a billion-dollar deal in 2011. An independent advisory panel to the U.S. Food and Drug Administration recently recommended T-VEC be approved, and researchers expect word within months from the agency.
FDA staff had initially expressed concerns about T-VEC, saying, among other things, that it was unclear from the study whether the treatment offered improved overall survival benefits to patients. Median overall survival differed by 4.4 months between T-VEC and the control group, the study says.
Researchers and melanoma experts say the best hope for patients may be combining T-VEC with another type of treatment called immune checkpoint inhibitors, which Chesney says “release the brakes in the immune system.” He’s currently testing this combined therapy in another trial at the Brown Cancer Center.
Richard Daugherty, a 52-year-old patient of Chesney’s from Jeffersonville, Ind., is undergoing this therapy for internal melanoma centered inside his groin and pelvis. When he was diagnosed in March, another doctor gave him up to a year to live. Melanoma, the deadliest form of skin cancer, kills about 9,000 Americans a year. It strikes 70,000 and is on the rise.
But in Daugherty’s case, one treatment with T-VEC reduced the size of tumors where it was injected by about 20% — and the only side effect he felt was fatigue.
Upon hearing the results before his second injection last week, “I thought I was imagining things,” he says. “The excitement and hope is amazing. I completely feel like I’ll go into … remission.”
Timothy Turnham, executive director of the Washington, D.C-based Melanoma Research Foundation, agrees that combination therapy seems to be the best approach. He says the results of T-VEC alone were “interesting but not amazing,” but when used with immune checkpoint inhibitors “the numbers you get are much, stronger,” and this combined treatment may prove to be a game-changer for advanced melanoma treatment, especially given the relatively mild side effects.
Melanoma patient Mary Kenna Deddens, 66, is currently getting T-VEC at Brown Cancer Center, and says she hopes the FDA approves it for wide use because patients with advanced melanoma need more options.
“It would help a lot of people,” she says. “It’s another tool in the tool box.”
sourse USA TODAY http://www.usatoday.com/story/news/nation/2015/06/01/modified-herpes-virus-attacks-melanoma/28305287/