Melanoma vaccine shows promise in
vaccine made from a mixture of four melanoma molecules known as
peptides has produced an immune response in 75 percent of the
patients enrolled in a clinical trial at the University of Virginia
The results of the randomized, phase II clinical trial, which
involved more than two dozen people with advanced melanoma, the
most deadly form of skin cancer, were published in the Nov. 1
online Journal of Clinical Oncology (www.jco.org).
“There have been significant tumor regressions on this protocol
of peptide vaccines against melanoma,” said Dr. Craig
L. Slingluff Jr., professor of surgery and director of the
Human Immune Therapy Center at U.Va. “This gives us hope
that this approach may be useful for patients with advanced disease.”
In the trial, 26 patients with stage III or IV melanoma received
six vaccinations of the multi-peptide mixture developed at U.Va.,
followed by a tetanus helper peptide and a low dose of an anticancer
drug known as interleukin-2.
The vaccines used during the trial were prepared in two injectable
forms. One form included an emulsion of granulocyte macrophage-colony
stimulating factor (GMCSF), a type of protein secreted by immune-system
cells that helps to regulate the immune response. Half the patients
received the GMCSF emulsion, and their immune response was significantly
improved over that of the other patients.
“Multi-peptide vaccines with this emulsion warrant continued
investigation,” Slingluff said.
The research team is keeping the GMCSF arm of the melanoma vaccine
trial open, and has offered booster vaccines to some patients
with evidence of tumor regression or stable disease. The team
is also evaluating the impact of low-dose interleukin-2 combined
with the melanoma vaccine on the immune system’s killer
or cytotoxic t-cell responses.
According to the American Cancer Society, more than 53,000
new cases of melanoma are expected this year.