June 6 (UPI) -- Researchers have developed a three-drug combination that may be effective in combating advanced melanoma, a study says.
Their work showed a combination of inhibitor drugs that block a form of melanoma known as BRAF V600E, helpeding to extend the lives of people with the disease, according to the results of two clinical trials published Thursday in the journal Nature Medicine.
"Utilizing the three drugs together sensitized the patient's own immune system to bolster the power of immunotherapy and block the growth of two genes - BRAF and MEK - that cause cancer cells to reproduce and grow out of control," Antoni Ribas, a researcher at UCLA and the study's senior author, said in a news release.
The first phase of the study showed the three-drug combination worked safely. The drugs included dabrafenib and trametinib, which blocked BRAF mutation, and immune checkpoint inhibitor drug pembrolizumab.
For the second phase, the researchers recruited participants from around the world, 60 who took the drug combination and 60 got dabrafenib and trametinib, along with a placebo.
The phase 2 trial proved an initial treatment of pembrolizumab, followed by a double dosage of dabrafenib and trametinib, could stop the progression of melanoma for an average of 16 months.
A combination of dabrafenib, trametinib and placebo halted the disease for an average of 10.3 months.
People in the three-drug combo group had worse prognoses than the placebo group, the researchers say.
Past studies that tested use of only one of the three drugs resulted in shrinking tumors in a low percentage of melanoma of patients. Two-drug combinations didn't show much success either.
According to the Centers for Disease Control and Prevention, melanoma causes more than 9,000 skin cancer deaths annually.
"The results of the triple therapy is so much more encouraging than double-therapy combinations with these drug agents," Ribas said. "With this triple combination, we're doing two things at once: using the two inhibitors to block the cancer from spreading, and stimulating the immune system. An immune response has the ability to remember foreign invaders and help protect the body from similar infections in the future, so enlisting an immune response to the cancer is aimed at having more durable responses to the therapy."