ASCO Annual Meeting
May 16, 2012
A small analysis of a larger study showed that combining two different targeted therapy drugs, dabrafenib and trametinib, stopped advanced melanoma from worsening while causing less severe side effects than the current standard targeted therapy drug. Targeted therapy is a treatment that targets a cancer's specific genes, proteins, or the tissue environment that contributes to cancer growth and survival. Specifically, dabrafenib targets changes in the BRAF gene, and trametinib targets changes in the MEK gene to stop melanoma growth.
About half of melanomas have a specific genetic change in the BRAF gene that drives cancer growth. In these tumors, the MEK gene often contributes to tumor growth, as well. The current standard targeted therapy approved by the U.S. Food and Drug Administration in 2011, vemurafenib (Zelboraf), also targets the BRAF gene. However, the drug eventually stops working for most patients, highlighting the importance of additional treatment options.
This analysis included a subgroup of 77 patients (out of 125 patients in the main study who received dabrafenib and trametinib) with advanced melanoma who had not yet received any treatments that target the BRAF gene. Although the study is ongoing, so far these patients have not had their cancer worsen for about 7 months, which is similar to studies on vemurafenib. This means that the new drug combination appears to work as well as the current standard targeted therapy. However, studies on vemurafenib have shown that up to 25% of patients develop skin side effects, such as skin cancer and other precancerous skin conditions. In this recent study, 2% of the 125 patients receiving dabrafenib and trametinib developed these skin conditions, which means the combination of these drugs appears to cause fewer side effects than the previous research on vemurafenib has shown.
What this means for patients
“Not only are the two drugs shrinking the cancer, but we're seeing that a second anticancer therapy may actually lower the side effects of the first,” said Jeffrey Weber, MD, PhD, a senior member at H. Lee Moffitt Cancer Center and Director of the Donald A. Adam Comprehensive Melanoma Research Center in Tampa, Florida. Research on dabrafenib and trametinib is ongoing, and these drugs are not yet available outside of clinical trials. Talk with your doctor about all treatment options for melanoma, including clinical trials.
Questions to ask the doctor
- What stage of melanoma do I have? What does this mean?
- What are my treatment options?
- What clinical trials are open to me?
- Will targeted therapy be an option for treatment? If so, which drugs will be used?
- What is my prognosis (chance of recovery) with these drugs?
- What are the possible side effects? How will they be managed?
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