Researchers have found that a new drug for metastatic melanoma nearly doubles the median survival time for patients with a common genetic mutation.
The data come from an international phase 2 study of the drug Zelboraf (vemurafenib). More than half of the 132 patients who were treated with the novel agent responded to treatment and experienced a median overall survival of almost 16 months. Patients with this advanced form of melanoma, in which the cancer has spread to other organs, typically survive about 9 months.
Results from the trial, led by coprincipal investigators Jeffrey Sosman, MD, director of the Melanoma Program and coleader of the Signal Transduction Program at Vanderbilt-Ingram Cancer Center; and Antoni Ribas, MD, professor of hematology/oncology at UCLA’s Jonsson Comprehensive Cancer Center, were published in the February 23 issue of the peer-reviewed New England Journal of Medicine.
“Many of our patients are exhibiting a strong, immediate response to this drug and some are living significantly longer, with manageable side effects,” said Sosman, professor of medicine at Vanderbilt University Medical Center.
“This study shows that Zelboraf changes the natural history of this disease,” Ribas said. “We’re seeing a significant number of patients with durable responses to the drug, and that the whole group of treated patients is living longer. These results tell us that this drug is having a very big impact, and this changes the way we treat metastatic melanoma.”
All the patients enrolled in the study were diagnosed with stage IV, BRAF-positive melanoma and had received at least 1 form of systemic treatment prior to enrollment.
A partial response to the drug was seen in 47% of patients, and 6% exhibited a complete response, for an overall response rate of 53%.
While the clinical trials for vemurafenib have been positive to date, the main limitation with vemurafenib is that tumors eventually become resistant to the drug. Jonsson Cancer Center researchers are studying this resistance, Ribas said.
“We are trying to determine what is causing this drug resistance and are searching for new therapies that we can use, perhaps in combination with vemurafenib,” said Sosman.
Sources: Vanderbilt University Medical Center; UCLA.