GlaxoSmithKline (GSK) has won approval from the European Medicines Agency (EMA) for melanoma treatment Mekinist, which becomes the first drug in the MEK inhibitor class to be licensed in Europe.
Mekinist (trametinib) has been cleared in the EU as a monotherapy for adults with unresectable or metastatic melanoma who have the BRAF V600 mutation, more than a year after it was given a green light in the US.
The approval is good news for GSK but also for Novartis, which reached an agreement to acquire Mekinist along with several other oncology assets from GSK in a $16bn deal that is due to close early next year.
Around half of all melanoma patients have mutations in the BRAF protein kinase gene, and V600 accounts for the majority of this group.
Approval was based on data from the METRIC study of 322 patients with metastatic melanoma, who tested positive for BRAF types V600E or V600K and were either treatment-naïve or had received one prior course of chemotherapy course.
Results demonstrated that Mekinist significantly improved progression-free survival (PFS), with patients on GSK’s drug achieving median PFS of 4.8 months, compared with 1.5 months for chemotherapy alone.
Mekinist will compete in the marketplace most closely with Roche’s Zelboraf (vemurafenib), which was approved in 2012 for the treatment of advanced melanoma patients with the BRAF V600 genetic mutation. However, Zelboraf has a different molecular target in the form of BRAF kinase.
GSK also has a BRAF inhibitor on the market – called Tafinlar (dabrafenib) – and won approval for combination use of Mekinist and Tafinlar in the US earlier this year. In the EU, however, the company was forced to withdraw a marketing application for the combination product after it became clear the EMA would need additional data.
Mekinist as a monotherapy will also compete with Bristol-Myers Squibb’s (BMS) anti-CTLA-4 antibody Yervoy (ipilimumab), which is licensed for broader use in melanoma.
Market research firm Decision Resources predicts that BRAF/MEK inhibitor combinations will become the treatment of choice for BRAF-positive melanoma, although it says the bulk of the melanoma market will be taken up by immune checkpoint inhibitors – BMS’ nivolumab and Merck & Co’s pembrolizumab (MK-3475) – which are currently in late-stage testing.