Evaluation of the Impact of Adjuvants Accompanying Peptide Immunization in High-Risk Melanoma

This study will evaluate the immunization effects of a vaccine for patients who are at risk for recurrence of their skin cancer. That is, the risk of cancer is higher if melanoma has invaded deep into the skin or lymph nodes. Currently, the only therapy that the U.S. Food and Drug Administration (FDA) has approved for preventing recurrence of melanoma is alpha-interferon. But the research data are controversial. In this study, the vaccine to be used, called gp100, contains a piece of a protein called a peptide, which melanoma cancer cells produce.

Patients 16 and older who have had confirmed melanoma surgically removed and whose tissue type is tested as being human leukocyte antigen serotype within HLA-A serotype group (HLA-A2), through a specific blood test, may be eligible for this study.

Up to 132 participants will be enrolled. There will be a physical examination and collection of blood samples for tests, and making sure that x-rays and scans are current. Patients will be randomly assigned to four groups. Group 1 will receive the peptide with an adjuvant (assistant) oil-based liquid called Montanide ISA-51, as an injection in the thigh. Group 2 will receive gp100, Montanide, and a cream called imiquimod, which the FDA has approved for treating genital warts and herpes but that may help immune cells in the skin to recognize the vaccine. Imiquimod will be applied to the skin for 5 days. Group 3 will receive gp100 mixed in salt water given as several mini-doses under the skin of the thigh. Group 4 will also receive several mini-doses of gp100 mixed in saline, as well as imiquimod cream applied to the skin for 5 days. All patients will receive the gp100 every 3 weeks for 12 weeks. Every dose is a cycle, with four cycles considered a course of therapy. If the melanoma does not return or patients do not experience side effects from this therapy, then the courses of vaccine will repeated for up to 12 cycles of therapy (3 courses over 33 weeks). Side effects of the peptide vaccination include local swelling, swelling of local lymph nodes, bruising, and pain and redness at the injection sites. There may be chills or fever. Patients will be watched closely for such side effects.

To study how the vaccine changes the action of cells in the immune system, patients' white blood cells (lymphocytes) will be obtained, involving a separate informed consent. The procedure, called leukaphersis, requires inserting a needle into the arm, to obtain blood going into a machine, which divides the blood into red cells, plasma (or the serum part), and lymphocytes. The lymphocytes are removed, and the plasma and red cells returned to the patient through a second needle in the other arm. Risks associated with the procedure include fainting, which can be prevented by patients' eating before coming to the lab, and bleeding and infection at the needle site. Patients will undergo leukapheresis will be done about four times: before receiving the vaccine, 3 weeks after the first four doses, and then after 8 cycles and 12 cycles. Patients assigned to the groups receiving imiquimod will be asked to record every time they apply that cream and describe any symptoms developed during the study. All patients will be watched closely for any sign that their melanoma has returned. Before and throughout the study, multiple blood tests will be conducted.

The vaccine, Montanide, and imiquimod may increase patients' immune system in fighting off new tumors, but that is not known now. However, the study may provide information that will be useful in treating melanoma patients in the future.