(RxWiki News) Melanoma, the most dangerous form of skin cancer, now has two new enemies. The FDA has approved two drugs to treat melanoma that has spread to other organs (metastatic) or can’t be surgically removed.
Tafinlar (dabrafenib) and Mekinist (trametinib) were approved to treat patients with particular genetic tumor mutations.
Tafinlar treats patients who have tumors with BRAF V600E gene mutation. Mekinist is targeted therapy for individuals who have altered BRAF V600E or V600K genes.
About half of all melanomas have a faulty BRAF gene.
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Along with the medication approvals, the FDA approved a genetic test that looks for these faulty genes. It’s called the THxID BRAF test.
The two new medications join two others approved last year for advanced melanoma – Zelboraf (vemurafenib) and Yervoy (ipilimumab).
Melanoma is the leading cause of death from skin disease. Nearly 77,000 Americans will be diagnosed with melanoma and 9,500 will die from the disease in 2013.
The FDA approval of Tafinlar is based on a study of 250 patients BRAF V600E gene mutation-positive metastatic or unresectable melanoma.
Compared to patients taking a chemotherapy drug called dacarbazine, patients taking Tafinlar saw a delay in tumor growth of 2.4 months.
Mekinist was approved based on a study involving 322 patients with advanced melanoma with BRAF V600E or V600K gene mutations.
Compared to chemotherapy, tumor growth was delayed by 3.3 months. However, patients who had previously used Tafinlar or another BRAF inhibitor did not appear to benefit from Mekinist.
Common side effects of Mekinist included rash, diarrhea, tissue swelling and skin outbreaks. The most serious side effects seen in Mekinist-treated patients included heart failure, lung inflammation, skin infections and loss of vision.
For Tafinlar, the most common side effects were thickening of the skin (hyperkeratosis), headache, fever, joint pain, non-cancerous skin tumors, hair loss and hand-foot syndrome.
The most serious side effects reported in patients receiving Tafinlar included an increased risk of skin cancer (cutaneous squamous cell carcinoma), fevers that may be complicated by hypotension (low blood pressure), severe rigors (shaking chills), dehydration, kidney failure and increased blood sugar levels requiring changes in diabetes medication or the need to start medicines to control diabetes.
These medications may cause fetal harm in pregnant women and potentially infertility in men and women.
The wholesale price for Mekinist is $8,700 for a 30-day supply or $52,200 for a 6-month treatment course.
Tafinlar is $7,600 for a 30-day supply, with an estimated total of $45,600 for a typical 6-month treatment course.
Tafinlar and Mekinist are marketed by GlaxoSmithKline, based in Research Triangle Park, N.C. The THxID BRAF Kit is manufactured by bioMérieux of Grenoble, France.
