Immune therapy is promising
An experimental immune therapy may provide a new way to fight advanced melanoma, a devastating cancer that often kills patients within six months.
In a study of two novel treatments — a therapeutic vaccine called gp100 and an immune stimulator called ipilimumab — ipilimumab nearly doubled the number of patients surviving one year, found a study presented Saturday at the American Society of Clinical Oncology. About 25% of those given the vaccine lived one year, compared with 46% of those on ipilimumab.
Patients who received the vaccine lived a median of six months. Those given either ipilimumab alone or a combination of the two drugs lived about 10 months, according to the study of 670 patients, funded by Bristol-Myers Squibb and Medarex Inc., which developed ipilimumab.
Doctors say that even modest success is reason for hope in this disease. Ipilimumab is the first drug to improve advanced melanoma patients' survival in a large, definitive trial, says study author Steven O'Day, director of melanoma research at the Angeles Clinic and Research Institute in Santa Monica, Calif.
Ipilimumab works by harnessing the immune system's power to fight cancer, says Lynn Schuchter, chief of hematology and oncology at the University of Pennsylvania's Abramson Cancer Center, who has used the drug with her patients. The drug "turns off the brakes" on key disease fighters called T-cells, Schuchter says.
But revving up the immune system can cause the body to attack healthy tissue, too, O'Day says. In his study, those who got the most benefit from the drug were also the most likely to develop autoimmune problems.
About two-thirds of patients developed side effects such as skin rashes, diarrhea, thyroid imbalances or hepatitis. Although most complications were manageable with medication, 10% to 15% of side effects were severe.
About 1.5% of patients given ipilimumab died from the treatment, mostly because of intestinal perforations, O'Day says.