MONDAY, April 18, 2016 (HealthDay News) -- More than one-third of advanced melanoma patients were still alive five years after starting therapy with the cancer drug nivolumab (Opdivo), researchers are reporting.
"In 2012, we saw some very promising early evidence that this drug could not only cause the regression of very advanced cancer in patients with melanoma, lung or kidney cancers that had not responded to other forms of therapy, but we also saw that these responses appeared to be very durable," said lead researcher Dr. Suzanne Topalian. She is a professor of surgery and oncology at Johns Hopkins University School of Medicine, in Baltimore.
Opdivo was approved for the treatment of advanced melanoma by the U.S. Food and Drug Administration in 2014.
The results of this follow-up study, funded by Bristol-Myers Squibb, which makes Opdivo, were to be presented Sunday at the American Association for Cancer Research's annual meeting, in New Orleans. Research presented at meetings should be viewed as preliminary until published in a peer-reviewed journal.
According to U.S. National Cancer Institute data, only 16.6 percent of patients with advanced melanoma diagnosed between 2005 and 2011 survived five years or more.
In this follow-up of a trial started in 2008 of 107 patients, the researchers found Opdivo was effective over the long term.
In 2014, Topalian and colleagues published a paper in the Journal of Clinical Oncology that showed some patients had lasting responses that continued even after stopping the drug.
A year after starting treatment, almost 65 percent of patients were still alive. After 48 months, survival dropped to 35 percent, where it remained, the researchers found.
In the latest report, researchers also compared the drug with another FDA-approved melanoma drug, ipilimumab (Yervoy). About 21 percent of patients treated with Yervoy were still alive as much as 10 years after treatment, Topalian said.
She added that Opdivo and Yervoy are approved to be used together, and the response rate with the combination is over 50 percent.
However, mixing the drugs can produce toxic side effects, Topalian said. "There may be better ways to give the combination, and that is now in clinical testing," she explained.
Opdivo's side effects include inflammation in normal tissue in other organs caused by the drug's effect on the patient's immune system, Topalian said. However, these side effects can be diagnosed early and treated aggressively, she added.
"We are now at a point where these drugs are quite safe. The risk-to-benefit balance appears to be favorable," she said.
"Opdivo releases the brakes on the immune response against cancer by blocking this molecule called PD-1," she explained. This allows the immune system to "do its job and kill the cancer."
In addition to advanced melanoma, Opdivo is being tested in patients with less advanced disease, as well as in patients with advanced lung and kidney cancer, Topalian said.
She considers Opdivo a breakthrough in the treatment of melanoma. However, it is expensive, costing more than $103,000 over seven months, according to a 2015 presentation at the American Society of Clinical Oncology. The drug is covered by most insurance plans, including Medicare, after an initial co-pay.
"We are all hoping for a cure," Topalian said. "Cure is always the ultimate goal in oncology. Other things may result from this form of therapy that are good outcomes -- that would be turning cancer into a chronic, manageable disease that people can live with for a very long time."
One expert said melanoma is no longer a death sentence.
"The average survival for a patient with advanced melanoma was six months," said Dr. Craig Devoe, acting chief of the division of hematology and oncology at Northwell Health Cancer Institute, in Lake Success, N.Y.
"This is more support to prior data that we can see long-term remissions and ostensible cures," Devoe added.
Visit the American Cancer Society for more on melanoma.