Promising study results with a new vaccine to treat melanoma, called Melacine®, have led its manufacturer to announce that it will file for approval with the U.S. Food and Drug Administration (FDA) by the end of the year 2000.
Melanoma is a type of cancer of the skin that can
metastasize, or spread, quickly to other parts of the body. Treatment usually includes surgery to remove the cancer and surrounding tissue. Depending on the stage of melanoma (extent of disease at diagnosis), individuals may also receive chemotherapy, radiation therapy, and/or biologic therapy after surgery. To improve the effectiveness and reduce the side effects of treatments that are available, researchers continue to study new drugs and new types of therapies.
Vaccines are an important subject of study for cancer treatment because they frequently offer effectiveness against disease, without the serious side effects associated with many chemotherapy drugs. Vaccines work by helping the immune system to defend the body against infection and other forms of intrusion. A company called Corixa has developed a vaccine,
Melacine®, to help treat persons with melanoma. The Melacine vaccine is made of broken cells from 2 different types of human melanoma cells, plus other components that help to activate the immune system. Studies of this vaccine continue; however, because of the positive results found from previous studies, Melacine has received approval for use in Canada and will be soon be submitted to the FDA for approval for use in the United States.
Researchers recently reported some of the study data on Melacine at the
Melanoma at the Millennium meeting held in Phoenix. The first 106 persons with melanoma who received the vaccine had an objective response rate of about 20%; 4 persons with metastatic disease are still alive 10 to 13 years after treatment. Other studies conducted at several medical centers showed objective response rates of only 8 to 10%; however, 23% of patients did experience a stop in the growth of the cancer for an average of 23 months. These promising findings led to a subsequent study in which Melacine was used after chemotherapy.
Forty-four persons with stage III melanoma received chemotherapy with cyclophosphamide, then received the Melacine vaccine. The complete survival rates for this group have not yet been determined; however, thus far, 66% of persons are alive and 46% have not had any progression of the cancer. Another study compared treatment with Melacine with treatment with a 4-drug chemotherapy combination. These results showed similar response and survival rates, but significantly fewer side effects with the vaccine. This study led to the approval of Melacine in Canada.
A recent study done by the Southwest Oncology Group evaluated 689 persons who underwent surgery for stage II melanoma (with no spread to the lymph nodes). Some persons received Melacine after surgery; some did not. One analysis of the results showed a difference in recurrence (return of cancer) rates of 30% and 36%, favoring the Melacine group. However, a second analysis showed no difference between the 2 groups. The results from other studies, including 1 that combines Melacine with a biologic therapy called interferon-alfa, are being awaited.
Data from previously conducted studies of Melacine appear to be favorable. The use of Melacine in combination with other therapies such as chemotherapy, may prove to be a particularly promising treatment option for persons who have undergone surgery for melanoma. The complete findings from recent and currently ongoing studies are needed to determine the effectiveness and safety of this new vaccine. Persons with melanoma may wish to talk with their doctor about the risks and benefits of the Melacine vaccine, or of participating in a clinical trial in which other new treatments are being studied. Sources of information on ongoing clinical trials that can be discussed with a doctor include a comprehensive, easy-to-use service provided by the National Cancer Institute (cancer.gov).