WEDNESDAY, May 16 (HealthDay News) -- A preliminary, first-stage study funded by a pharmaceutical company shows promising results for an experimental double-drug therapy for melanoma.
The two drugs, known as dabrafenib and trametinib, appeared to delay progression of the potentially deadly skin cancer with fewer side effects than an existing drug called vemurafenib (Zelboraf).
However, the research into the drug combination is only in the first of three phases required before the U.S. government can approve its use. The first phase is designed to test the safety of a medication, not whether it works.
Unlike some other cancers, melanoma has stubbornly resisted advances in treatment. About 70,000 Americans are diagnosed with melanoma each year, and about 8,000 of those will die from the disease.
Researchers tested the drug combo in patients with advanced melanoma and a genetic mutation that exists in about half of all melanomas.
"Not only are the two drugs causing shrinkage of the cancer, but we're seeing that a second anti-cancer therapy may actually suppress the side effects of the first," said Dr. Jeffrey Weber, director of the Donald A. Adam Comprehensive Melanoma Research Center at the H. Lee Moffitt Cancer Center, Tampa, Fla., in a news release from the American Society of Clinical Oncologists.
Vemurafenib, approved last year, aims to prevent progression of the cancer in these patients. But patients' tumors eventually become immune to its effects.
The new analysis looks at 77 patients who took the combination therapy. Their cancer didn't progress for an average of 7.4 months, similar to what was seen in previous research with vemurafenib only. The researchers haven't released statistics about their survival rates.
Skin lesions, a side effect, were much less common in the patients on the combination therapy than in patients who took vemurafenib.
Ashani Weeraratna, an assistant professor in the Molecular and Cellular Oncogenesis Program at the Wistar Institute, Philadelphia, agreed that the combo therapy does seem to reduce the skin lesion side effects.
"This is important for patients that, in addition to battling a deadly disease, also have to deal with the discomfort associated with the secondary lesions," Weeraratna said. "Having said that, I do think most of us would pick getting what is essentially an uncomfortable rash over not receiving a cutting-edge therapy that might eradicate our metastatic melanoma."
Dr. Martin Weinstock, a professor of dermatology and epidemiology at Brown University in Providence, R.I., expressed some caution. "Ideally, what we need is to figure out how to cure most people with a regimen that doesn't have devastating side effects," he said. "We don't have that yet, and it doesn't look like this will be that either."
The results were scheduled for release Wednesday, prior to presentation June 4 at a meeting of the American Society of Clinical Oncologists in Chicago. The data and conclusions should be viewed as preliminary until published in a peer-reviewed journal.
The study was funded by the drug company GlaxoSmithKline, and Weber has received financial support from the pharmaceutical company.
For more about melanoma, see the U.S. National Library of Medicine.
SOURCES: Martin Weinstock, M.D., Ph.D., professor of dermatology and epidemiology, Brown University, Providence, R.I.; Ashani T. Weeraratna, Ph.D., assistant professor, Molecular and Cellular Oncogenesis Program, Wistar Institute, Philadelphia; May 16, 2012, abstract, news release, American Society of Clinical Oncologists
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