A study published in the New England Journal of Medicine finds that an experimental melanoma vaccine called the gp100 peptide vaccine shrank skin tumors and slightly extended progression-free survival in a Phase III trial of 185 patients with an advanced form of the disease. The research was sponsored by the Goshen Center for Cancer Care at Indiana University Health with support from the National Cancer Institute.
Patients were given either the standard therapy of interleukin-2 or interleukin-2 plus the vaccine. Sixteen percent of patients in the vaccine arm saw their tumor shrink by 50 percent, compared to just six percent of those in the control arm. Additionally, the vaccine slightly improved progression-free survival from 1.6 months to 2.2 months. Those who got the therapeutic shot lived seven months longer than the interleukin-2 group.
"This is the first time that a vaccine has shown benefit in the treatment of patients with metastatic melanoma, and it's an early example of success with a cancer vaccine," noted the study's lead author Doublas Schwartzentruber in a HealthDay report.
The gp100 peptide vaccine "primes" the immune system to recognize a protein that's present in melanoma, thereby prompting the body to recognize and attack that protein. Schwartzentruber says his team plans to build on this success by formulating a more effective version of the vaccine. "We have now a strong proof of principal that with an immunological treatment we can see benefit, but at this point the benefits are small," Schwartzentruber told HealthDay. "What we've decided to do is to try to develop a more potent vaccine before we do another trial."