Mekinist Is Approved By The FDA For Melanoma
By Cyndi Root
Mekinist was approved for treatment of advanced melanoma. Mekinist approval by the Food and Drug Administration (FDA) for use with Tafinlar represents the first time two drugs have been approved for combination use to treat the life-threatening skin cancer. In 2013, the FDA approved Mekinist (trametinib) and Tafinlar (dabrafenib) for single use. However, researchers demonstrated during a clinical trial that use of the two drugs together improved outcomes. Approval was granted under the FDA’s accelerated approval program. GlaxoSmithKline markets Mekinist and Tafinlar.
Richard Pazdur, M.D., director in the FDA’s Center for Drug Evaluation and Research, said, “This approval illustrates the value of continuing to study drugs in combination for clinical development.” He pointed out that the combination approval demonstrates the need for basic science research and for understanding the biological processes of melanoma.
The Molecular Pathway
Mekinist and Tafinlar act on the same biological pathway. The RAS/MAPK pathway regulates growth, division, differentiation, migration, and self-destruction. Normally, the BRAF protein operates in the pathway and regulates normal growth, but it becomes mutated in about half of melanoma cases. The BRAF gene is an oncogene because of the potential it has to cause cancer. Mekinist and Tafinlar specifically target the mutation and block signals in the molecular pathway.
Clinical Trials
Researchers conducted a clinical trial with 162 people. All had melanoma with the BRAF mutation, the cancer could not be removed surgically, and most had not received any kind of drug treatment. Mekinist and Tafinlar were given to some patients, while others received only Tafinlar. Of the people treated with the combination of Mekinist and Tafinlar, 76 percent experienced the tumor shrinking or disappearing and the effects lasted an average of ten months. Those treated with just Tafinlar had improving tumors for an average of five months. Further studies will measure survival rates.
Patients had some side effects with the combination drug usage. Symptoms included chills, fever, nausea, swelling in the hands and feet, and decreased appetite. Some patients experienced more severe side effects such as heart failure, kidney failure, blood clots, and eye problems. However, the incidence of squamous cell carcinoma of the skin was reduced to 7 percent compared to the 19 percent incidence with just Tafinlar treatment. The FDA advises physicians to warn patients that the two drugs may cause fertility problems and birth defects.
Source: http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm381159.htm