The immune-boosting drug, Interleukin-2, enhances the vaccine's effectiveness by stimulating the production of lymphocytes, a type of white blood cell that circulates throughout the body. More circulating lymphocytes means there are more cells available to do the job the vaccine has educated them to do.
Ninety-four patients in the Interleukin-2 arm of the study were enrolled and 93 were treated and evaluated for response. In the Interleukin-2 and peptide vaccine combination arm of the study, 91 were enrolled, 86 were treated and 85 were evaluated for response.
About 16 percent of study participants given the vaccine and Interleukin-2 combination saw tumors shrink by 50 percent or more, compared to 6 percent given Interleukin-2 alone.
Those in the vaccine and drug combination group also had slightly longer progression-free survival rates of 2.2 months compared to 1.6 months, which means those participants had more time in which the tumor did not grow.
Patients given the combination also lived an average of nearly seven months longer than those only give Interleukin-2 -- 17.8 months longer compared to 11.1 months.
In order for this vaccine to work, patients had to have a particular tissue type, called HLA-A2, which is present in about half of whites.
According to the American Cancer Society, melanoma has one of the fastest growing incident rates of all cancers. The five-year survival rate for melanoma patients is less than 10 percent.
Interleukin-2 is already FDA-approved to treat metastatic melanoma and kidney cancer.
The next step is to improve the vaccine's efficacy. Researchers hope to improve upon the study's findings by combining the vaccine with other immune-stimulatory agents such as adjuvants, other cytokines and antibodies that
|Contact: Deb Song|
Rush University Medical Center