Vemurafenib Receives Approval for Metastatic Melanoma

The FDA approved vemurafenib and a companion diagnostic test in a move that was hailed as an advance for both patients and personalized medicine.

The FDA approved the melanoma drug vemurafenib along with a companion diagnostic test in a move that was hailed as an advance for both patients and personalized medicine.

The drug received approval for the treatment of patients with BRAFV600E-positive unresectable or metastatic melanoma. The companion test, titled cobas 4800 BRAF V600, can be used to identify patients eligible to receive treatment.

The approval for both the test and drug were based on results from the BRIM3 trial. The trial compared vemurafenib to dacarbazine in 675 patients with V600E BRAF-mutated melanoma, found using the cobas test. Patients receiving vemurafenib experienced a 74% reduction in disease progression (HR, 0.26; P <.0001) with a median progression-free survival of 5.3 months.

Twenty-six percent of patients receiving vemurafenib experienced the development of cutaneous squamous cell carcinoma, a type of non-melanoma skin cancer that is easily removed with surgery.

The confirmation for the drug, which Genentech will market under the name “Zelboraf,” marks the second new treatment approved this year for a disease that formerly had limited options.

"Just 2 years ago we had no drug that was shown to improve survival in patients," said Paul B. Chapman, MD, Memorial Sloan-Kettering Cancer Center (MSKCC) in New York, at ASCO in June. "This is an extremely exciting time for us and for our patients, because we now have choices."

The Bristol-Myers Squibb drug ipilimumab (Yervoy), a monoclonal antibody that blocks the cytotoxic T-lymphocyte antigen (CTLA-4) molecule, was also approved earlier this year for the treatment of unresectable and metastatic melanoma.

The two companies, Bristol-Myers Squibb and Roche, announced earlier this year that they plan to undertake a joint investigation into a combination of the 2 medications.

“These two medicines have very different mechanisms of action that complement each other quite nicely,” said Jedd D. Wolchok, MD, director of immunotherapy clinical trials at MSKCC at ASCO in June.

The cobas 4800 BRAF V600 mutation test is being heralded by the FDA as a first-of-a-kind test; its approval along side vemurafenib is noted as a huge step forward in personalized medicine. Despite the FDA requirement to conduct the cobas test before prescribing vemurafenib some doctors remain hesitant.

“The mutation test is not hard [to complete] but it will be a hassle for doctors to use that specific test. There are many laboratories able to test for V600E with various techniques,” said Howard A. Burris, III, MD, chief medical officer and executive director, Drug Development Program, Sarah Cannon Research Institute in Nashville, Tennessee.

There were 68,130 new cases of melanoma diagnosed in the United States during 2010 according the National Cancer Institute. Metastatic melanoma remains the deadliest form of skin cancer with an average survival rate of 6 months.

Related:Two Studies Herald New Era in Melanoma Therapy.