Melanoma Drug Trials Show Significant Promise
By targeting immune system, new treatments extend average survival
"You're really hitting two molecules that control immune activation at different locations," Sznol said. "There are multiple ways that lymphocytes are inhibited. Maybe if you hit two of those mechanisms you get better results than if you just hit one."
Sznol said he's "never seen anything quite like" the results from using the two drugs in combination.
"If you look at all 53 patients we've treated, the one-year survival is 85 percent and the two-year overall survival is 79 percent," he said. "It's hard to compare across studies, because it's a small study, but no matter how we select the patients, I've never seen a trial that had even close to a two-year survival of 79 percent."
The results are even more impressive considering that many of the patients already had undergone as many as three rounds of drug therapy for their melanoma, said Dr. Len Lichtenfeld, deputy chief medical officer for the American Cancer Society.
"Many of those patients were pretreated before they got this drug, which means earlier treatment had failed," Lichtenfeld said. "When you see results like that, you certainly stand up and take notice."
Phase 3, or final, trials have been completed regarding the combination therapy, Sznol said, and it's hoped the results will be out in a year.
The second clinical trial, which involved 951 patients, also reported strong results from Yervoy. It found that the drug reduced cancer's return by roughly 25 percent when compared to placebo, or dummy, medication in patients who had surgery for high-risk stage 3 melanoma.
The drug was given every three weeks for four doses, and treatment continued at three-month intervals up to three years. Three-year, recurrence-free survival rates were 46.5 percent in the Yervoy group, compared with 34.8 percent in the placebo group.
Both studies reported severe side effects, however. Five treatment-related deaths occurred in the second clinical trial, and about half the patients discontinued treatment because of side effects such as skin rash and inflammation of the colon, thyroid and pituitary gland.
Side effects appeared even more pronounced in the combination therapy trial. "When we give the two drugs together, we see a greater incidence of side effects," Sznol said.