Work in the field of cancer vaccines isn’t exactly what you might think. This method of treating cancers coaches the immune system to attack the cancer, not prevent it.
A group of researchers successfully concluded two simultaneous trials on a cancer vaccine, finding that it works well in treating patients with both melanoma and ovarian cancer.
Using the vaccine increased both length of remission and average lifespan in cancer patients treated.
The team from the Roswell Park Cancer Institute conducted two parallel phase II clinical studies using modified versions of the smallpox and fowlpox viruses, engineered to express a protein called NY-ESO-1, in patients with ovarian cancer and melanoma.
The vaccine uses a defused virus to trigger a response to a common cancer protein. After the vaccination, the immune system has been taught to attack that protein in other locations, and begins to seek out the cancer aggressively and specifically.
The two clinical trials, phase II of the vaccine testing, included a group of 25 melanoma patients and a separate group of 22 patients with ovarian cancer. All of the patients had been identified as having advanced or aggressive cancers.
Both groups were given the treatment, first a vaccine using a defused version of smallpox, and then again with another deactivated virus made from fowlpox as a booster. Linking the cancer protein NY-ESO-1 to two different virus exposures increases the response against the cancer significantly, and reinforces the immune system’s ability to learn.
Use of the vaccine successfully increased average patient survival by several months in both groups. Authors recommend further study of this technique, and further clinical trials are planned.
In the melanoma group, the cancer stopped growing in half of the patients. Complete or partial remission occurred in the other half of the group, with researchers concluding there was a documented clinical benefit in 72 percent of melanoma patients treated with the NY-ESO-1 vaccine.
On average, increased time for melanoma patients in the trial was 9 months before the cancer began to grow again, and the increase in lifespan was four years.
For ovarian cancer, the average time before the cancer began to grow was 21 months, and the increase in lifespan was also four years.
The study was published April 10 in the journal Proceedings of the National Academy of Sciences of the United States of America.
This research was part of several projects in the growing field of cancer immunotherapy, sponsored by both the Roswell Park Cancer Institute and Krankenhaus Nordwest as part of the Cancer Vaccine Collaborative (CVC). Cancer Research Institute and the Ludwig Institute for Cancer Research. Additional funding came from Krebsforschung Rhein-Main eV, RPCI and the National Cancer Institute.
Each year an average of 53,000 new cases of melanoma are reported, with over 7,000 people dying from it. It is the sixth and seventh most common cancer among men and women, respectively.
Although melanoma is the least common type of skin cancer (basal cell carcinoma is most common), it is the deadliest, as it makes up only 4% of all skin cancers, but 79% of skin cancer deaths. Melanoma is caused by a cancer forming in a skin cell called a melanocyte, the type of skin cell that gives us skin pigmentation.