Immunotherapy Effective for Melanoma

A new study of patients with advanced melanoma who had not responded to previous therapies has shown they experienced a significant reduction in the size of their cancers after receiving a new immunotherapy.

The immunotherapy consisted of a combination of chemotherapy and a reintroduction of their own (autologous) activated lymphocytes. These white blood cells were removed from the patient, activated to attack the tumor, then reintroduced into the patient. Thus, the patient's own immune system treated the tumor. These results were reported in the April 2005 issue of the Journal of Clinical Oncology.

The study involved 35 patients with melanoma that had progressed throughout the body. The patients had not responded when treated with standard therapies and had developed growing tumors. After blood was drawn from the patients, the lymphocytes were separated from other parts of the blood. Next, the patients were treated for two days with two chemotherapy agents: cyclophosphamide for two days and fludarabine for five days. These drugs reduced the number of lymphocytes circulating in the blood, thereby reducing competition for the newly activated tumor-fighting lymphocytes reintroduced into the bloodstream.

After seven days of chemotherapy, the patients received their own lymphocytes that had been renewed with increased tumor-fighting capacity. They also received a high dose of interleukin-2 (IL-2), a protein made by the body that makes the tumor-fighting cells mature and multiply. Of the 35 patients in the study, 18 experienced an improvement in the amount of tumor present in their body, while eight other patients demonstrated a mixed or minor response. Of those 18, 15 had a partial response that lasted from two months to more than two years. Three patients continued to experience complete disappearance of tumors.

"The results of this study are encouraging, and suggest that some patients with melanoma who do not respond to conventional treatments may get a durable benefit from treatments based on using their own immune cells,” noted Mark Dudley, Ph.D., coauthor of the study. The study was led by Steven A. Rosenberg, M.D., of the U.S. National Cancer Institute (Bethesda, MD, USA).




Related Links:
National Cancer Institute