New Vaccine Seeks to Destroy Cancerous Tumors

In London, scientists at the Guy's and St. Thomas' Biomedical Research Centre are overseeing a two-year clinical trial in which cancer patients are being treated with a special vaccine. The vaccine's job? To teach each patient's immune system how to seek out and destroy cancer cells.

But it's not an easy path. For one thing, patients with advanced stages of cancer may have a suppressed immune system. For another, the immune system may not be able to identify cancer cells as harmful.

Vaccines prime your body's immune system to fight future invasions from various diseases. Typically, a vaccine contains a weak or deactivated sample of the pathogen that causes the disease, which is usually a virus or bacterium. Once your body fights off this weak version, your immune system takes notes. If it ever encounters another example of that same pathogen, it can produce antibodies to stop the infection.

The new vaccine out of the U.K. falls under the category of immunotherapy, whose goal is to get a patient's body to slow cancer cell division or even fight off cancer cells. Ideally, immunotherapy reduces the need for other types of treatment like chemotherapy and radiation therapy. However, this vaccine is paired with a low dose of chemotherapy to help boost an immune response from the body. Most solid tumors should be susceptible to the process.

There are vaccines that are effective in preventing certain types of cancer, but they do so indirectly by fending off illnesses that can trigger cancer. An example is the human papillomavirus (HPV) vaccine. HPV can cause several types of cancer, including cervical and some throat cancers. By vaccinating against HPV, the chance of developing these types of cancers is drastically reduced.

Vaccines that target cancer directly have been in development for several years. One, called Provenge, received clearance from the U.S. Food and Drug Administration in 2010 as an immunotherapy drug for advanced prostate cancer. But Provenge is incredibly expensive (around $100,000 for a treatment) and extends survival by a median four months. 

Engineered T-cells are another big advance in immunotherapy. T-cells “remember” pathogens so your immune system can fight them off before you get sick. Scientists at the San Raffaele Scientific Institute and Vita-Salute San Raffaele University in Milan engineered special T-cells to see if they would remain active in the body long enough to be an effective treatment for cancer.

In a clinical trial, the scientists gave immunotherapy that included the engineered T-cells to 10 bone marrow transplant recipients. In a follow-up session 14 years later, the doctors discovered those T-cells were still active. Paired with a vaccine similar to the one from Guy's and St. Thomas', this treatment could be an effective preventive for cancer.

While the results are encouraging, it may be several years before a comprehensive approach is available. It's also possible that there are types of cancer that would require a different approach to treatment. But it may not be too long before a general cancer vaccine can be used in immunization.

Check out the video above to learn more about treating cancer with vaccinations.

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