In a new trial that could pave the way for future cancer treatments, patients with aggressive skin cancer were successfully treated with "virotherapy." This type of therapy uses a modified herpes virus to attack melanoma cells and even has shown the potential to overcome the cancer even when the disease has spread throughout the body.
These findings mark the first positive phase 3 trial results for virotherapy, where one disease is used to attack and defeat another. If the drug, known as V-TEC, is approved, it could soon be more widely available for cancer patients.
One of the most crucial aspects of this new therapy is its ability to fight and overcome the cancer even after it has spread to organs throughout the body, offering hope to patients who are facing the worst of prognoses.
Kevin Harrington, professor of biological cancer therapies at the Institute of Cancer Research London, who led the study, said, "This is the big promise of this treatment. It's the first time a virotherapy has been shown to be successful in a phase 3 trial."
The trial involved more than 400 patients with aggressive melanoma with one in four responding to the new treatment and 16 percent remained in remission after six months. Approximately 10 percent of the patients treated had complete remission with no detectable cancer remaining. If after five years the patients are still cancer free, this would be considered a cure.
According to Harrington, the results are encouraging because all the patients had inoperable, relapsed or metastatic melanoma with no convential treatment options available. "They had disease that ranged from dozens to hundreds of deposits of melanoma on a limb all the way to patients where cancer had spread to the lungs and liver," Harrington says.
The treatment works by attacking the cancer on two fronts. It is based on a genetically "neutered" version of the herpes virus which has been modified to prevent it from infecting healthy cells. Cancer cells produce their own version of a blocked protein that allow the virus to thrive within the cancerous tissue. The herpes multiplies quickly inside the cancer cells until they burst open spilling the virus into the surrounding area and triggering a secondary immune reaction against the tumor.
"We may normally think of viruses as the enemies of mankind, but it's their very ability to specifically infect and kill human cells that can make them such promising cancer treatments. In this case we are harnessing the ability of an engineered virus to kill cancer cells and stimulate an immune response," says Professor Paul Workman, Chief Executive of The Institute of Cancer Research.
"It's like an unmasking of the cancer," says Harrington. "The patient's immune system wakes up and attacks the cancer cells wherever they are in the body."
The drug has been submitted to both the FDA and the European Medicines Agency, and could be available in the US by next year if approved and in Europe soon afterwards.
