(RxWiki News) Melanoma, the potentially lethal form of skin cancer that can spread throughout the body, has a new enemy. The US Food & Drug Administration (FDA) has approved a new combination therapy.
The FDA has approved the use of Mekinist (trametinib) in combination with Tafinlar (dabrafenib) for treating melanoma that cannot be surgically removed and metastatic (has spread) melanoma with specific genetic mutations.
Tafinlar treats patients who have tumors with BRAF V600E gene mutations. Mekinist is targeted therapy for individuals who have altered BRAF V600E or V600K genes. Both are oral medications.
About half of all melanomas have a faulty BRAF gene.
The two mutations — BRAF V600E or V600K — must be detected with a test approved by the FDA. Tafinlar is not approved to treat wild-type (unmutated) BRAF melanoma.
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This approval is based on response rates and duration of response as demonstrated in a phase l/ll trial. Improvements in disease symptoms and overall survival have not been demonstrated.
The combination therapy was approved through the Accelerated Approval Programme and reviewed under a Priority Review designation. The accelerated approval is contingent on the results of an ongoing phase lll trial to demonstrate the benefits in a patient with inoperable and metastatic melanoma with BRAF V600E or V600K mutations.
The safety of trametinib (2 mg once daily) in combination with dabrafenib (150 mg twice daily) was evaluated in 202 melanoma patients during a phase l trial.
The phase ll part of the trial evaluated the overall response rate (ORR) and duration of response in 54 patients who received the combination therapy and 54 patients who were given only dabrafenib.
The investigators found that ORR was 79 percent for patients treated with the combination therapy and 54 percent for those treated with only dabrafenib. The median duration of the response was 10.5 months in the combination group and 5.6 months in the dabrafrenib group.
The independent radiologic review committee (IRRC) reviewed the data. IRRC-assessed ORR was 57 percent in patients treated with the combination, and the response lasted 7.6 months. For patients who received only dabrafenib, the ORR was 46 percent and the duration of response was 7.6 months.
Taking the two medications can cause serious side effects, including new skin cancers, promotion of unmutate BRAF melanoma, excessive bleeding, blood clots, heart problems including heart failure, eye problems, severe fevers, rashes, lung disease, blood sugar problems, anemia and potential harm to unborn babies in pregnant women.
Trametinib was in-licensed by GSK in 2006. GSK holds the worldwide exclusive rights to develop, manufacture and commercialize Mekinist, while Japan Tobacco retains co-promotion rights in Japan.
