(CBS)-- Metastatic melanoma is often considered a death sentence, since patients will live only six to ten months once diagnosed. A new study of a recently-approved melanoma drug offers hope.
The study found the drug, called vemurafenib, nearly doubled patients' life expectancy for an "impressive" 16 months.
"Many of our patients are exhibiting a strong, immediate response to this drug and some are living significantly longer, with manageable side effects," study author Dr. Jeffrey Sosman, professor of medicine at Vanderbilt University Medical Center, said in a written statement.
Metastatic melanoma is skin cancer that spreads to other parts of the body., such as the lungs or bones. About half of melanoma patients have a genetic mutation on the BRAF protein. Vemurafenib, sold by Hoffmann-La Roche as Zelboraf, was approved by the FDA in August for treating patients with melanoma who possess the mutated protein.
For the new study, published in the Feb. 22 issue of the New England Journal of Medicine, 132 patients with stage IV melanoma who hadn't responded to other treatments were given Zelboraf. The researchers found 53 percent of the patients responded to the drug and saw at least a 30 percent reduction in tumor size.
One of those patients was Debra Johnson of New Site, Miss., whose melanoma had already spread to one of her lungs and her lymphatic system when she was referred to Vanderbilt testing. Once doctors determined her tumor was BRAF-positive, she started treatment. After more than a year on the drug, she says her scans are clear and there is no visible evidence of melanoma.
"This treatment has been an answer to my prayer," said Johnson.
The FDA approved the drug based on a 675-patient study in which patients received either Zelboraf or a chemotherapy drug, HealthPop reported. The study found 77 percent of patients on Zelboraf are alive versus 64 percent of those taking the other drug by the study's end. But this new study puts a time-frame on the improved life expectancy.
"This study shows that Zelboraf changes the natural history of the disease," study co-author Dr. Antoni Ribas, professor of hematology/oncology at UCLA's Jonsson Comprehensive Cancer Center, said in the statement. "These results tell us that this drug is having a very big impact, and this changes the way we treat metastatic melanoma."
Dr. Michele Green, dermatologist at Lenox Hill Hospital in New York City, told HealthPop what's great about Zelboraf is that for the first time there's something that prolongs life, when before, "there was nothing, there was zero."
But she also said people will still die from the disease, and the drug is likely very expensive, so she hopes the future brings better options. WebMD reports a month's supply of Zelboraf costs around $9,400 a month.
"I don't think this is the best that's yet to be seen," Green said. "I think there's more out there."
The researchers say there's still more to be done on Zelboraf. While early studies have reported positive results, the majority of patients eventually experience disease progression. Sosman said in the statement the researchers are trying to determine what is causing resistance to the drug, and considering combination therapies that might prolong life expectancy.
About 76,250 people in the U.S. will be diagnosed with melanoma this year and about 9,200 are expected to die, according to the American Cancer Society.
Green says melanoma is so deadly, that if anyone notices something different on their skin, including a mole that's new or has changed, then go see a doctor immediately. A skin exam takes only ten minutes she said. Young people should be especially careful, since melanoma is a leading cause of cancer in young people, who typically don't worry about cancer risk as much as older folks.
"Skin cancer is so easily treated," Green said. "Nobody should die of melanoma."
The American Cancer Society has more on melanoma.