High-dose interferon alfa-2b (Intron-A) significantly prolongs survival in high-risk melanoma as compared to the melanoma vaccine known as GMK, according to early reports from a large, randomized trial. These results are from a multicenter study evaluating the use of these two treatments as additional (adjuvant) therapy in patients with thick melanomas or lymph node involvement after surgical removal of the primary tumor.
In this clinical trial (E1694), the GMK vaccine, which had shown some promise in earlier studies, was compared with high-dose interferon, the standard of care for melanomas that have a high risk for recurrence. The study randomly assigned 774 melanoma patients to either receive high-dose interferon for one year or the GMK vaccine given every week for a month and then every three months for two years. In April 2000 the trial was closed earlier than expected because one treatment was so clearly better than the other. Specifically, the patients receiving interferon had significantly better survival rates and decreased relapse rates than the patients receiving the vaccine.
Vaccines are an active area of clinical research in the treatment and prevention of many types of cancer. Although the GMK vaccine was not better then interferon in this trial, it remains under investigation for other stages of melanoma in multiple research centers outside of the United States.
Scott Saxman, M.D., of the NCI's Cancer Therapy Evaluation Program said the study's results suggest that "interferon as adjuvant therapy for high-risk melanoma is here to stay." One of the next questions to be addressed in the melanoma/interferon story, he said, is whether one month of interferon may be just as good as one year of interferon in patients with high-risk melanoma who have undergone surgery.