Could Fowlpox Vaccination Be Next Big Mesothelioma Treatment?
February 7, 2013
Deepak Chopra, one of the world’s most acclaimed holistic physicians, once told followers: “Instead of thinking outside the box, get rid of it.”
Several mesothelioma therapies currently under investigation fall outside the box of conventional treatments. Cancer stem cell research, biomarker research and developments in gene therapy are inspiring an ever-increasing range of options beyond surgery, chemotherapy and radiation therapy.
But while those treatments fall outside the box, a new treatment destroys its boundaries.
The therapy? A fowlpox vaccination.
Yes, that fowlpox vaccination — the shot that farmers traditionally give chickens and turkeys to prevent viral outbreaks of contagious lesions.
Recently, researchers have found a way to take the vaccine from the farmyard to the cancer center — and with surprisingly encouraging results.
Adapting the Fowlpox Vaccine for Mesothelioma Immunotherapy
Pox viruses are considered some of the most ideal agents for targeted cancer treatment. The viruses are considered safe to modify into a vaccine that help the body’s own immune system kill off cancer cells.
The fowlpox virus is especially easy to modify. Lab workers can design it to enter healthy cells and deposit a set of specific proteins that can trigger an immune response.
Once inside the body, the vaccine may also generate additional white blood cells that can continue carrying out the mission.
This concept lies at the heart of a new study, conducted by researchers at the University of Hawaii.
The study, which will appear in a future issue of the International Journal of Cancer, tested a fowlpox vaccination that was adapted to contain the protein known as survivin.
Survivin is “a protein that makes cancer cells resistant to chemotherapy,” the study’s lead researcher, Pietro Bertino, told Asbestos.com. The protein also regulates programmed cell death, a process known as apoptosis.
“My hypothesis was that, by survivin inhibition, all mechanisms that force the cancer cell to stay alive during chemotherapy could be turned off,” Bertino explained.
After he realized this protein could potentially play a major role in mesothelioma treatment, he had to find a way to get it into the body. An immunotherapy approach turned out to be the key. This is where the fowlpox vaccine comes in handy — it was the perfect vehicle to deliver the survivin to the tumors.
Bertino’s research team injected mice with malignant mesothelioma cells. They then provided a dose of the survivin-laced fowlpox vaccine. Some mice received the vaccine under the skin, while others received it directly into the peritoneum.
Both delivery methods produced a “significant immune response.” This response correlated with delayed tumor growth and improved overall survival. Better yet, none of the mice developed potentially serious side effects — like autoimmune conditions or infertility — after treatment.
Moving Forward with the Fowlpox Vaccine
Bertino’s team is now considering future directions for the vaccine.
“The fowlpox vaccine is our first attempt to induce an immune response against mesothelioma cells that can be used for both therapeutic and preventive purposes. We recently started collaborating with EpiVax — [and together] we identified a list of very immunogenic survivin peptides that should generate high responses in human subjects.”
When fully developed, this vaccine may have a distinct edge over other therapies.
“Successful immunotherapies have the advantage [of inducing] an immune response — that may persist years after vaccination. Chemotherapy, on the other hand, has an affect limited to a few days,” Bertino explained.
Because chemotherapy offers such a short response, patients have to participate in several cycles of the treatment.
“Repeating chemotherapy cycles usually induces high toxicity,” Bertino adds. The fowlpox vaccine could help patients avoid those serious side effects, which often include severe nausea and hair loss.
Certain vaccines also show more promising results than chemotherapy drugs, which rarely put mesothelioma into remission.
“With immunotherapy, our group induced complete tumor regression in animal models of mesothelioma. We never achieved a similar result in studies with chemotherapy.”
Since it is still in its animal testing phase, the fowlpox vaccine still has a long way to go before it is approved for human use. But Bertino feels that the promising results from his study can justify future clinical trials in due time.
As research teams continue to take the fowlpox vaccine to the next level, other vaccination options are already available through clinical trials.
Other Mesothelioma Vaccines
In 2010, researchers tested a vaccine made from a patient’s own immune cells and tumor antigens. The trial — the first human trial of its kind — found that the vaccine could help “jump-start” the immune system’s response to the tumors.
Early last year, a UK-based research group announced another vaccination trial, this time for the TroVax® shot. Once the study officially begins, the researchers will see if this virus-based vaccine can stimulate the immune system to attack cancerous cells.
Our clinical trial database can help interested patients find a vaccine trial near them. For more updates on the fowlpox vaccine — including notifications when it advances to human studies — be sure to check back for future news posts.