Suitable patients for GSK’s melanoma treatments must be identified using an accompanying genetic test

Two new drugs for the most deadly kind of skin cancer have been approved by the US Food and Drug Administration. The drugs are only effective in patients whose tumours express specific genetic mutations, which can be identified using a device approved alongside the drugs.

Tafinlar (dabrafenib) and Mekinist (trametinib) are approved to treat melanomas that have either metastasised (spread to secondary locations) or cannot be removed surgically. The tumours must also carry either the V600E or V600K variations in the BRAF gene, which plays a pivotal role in regulating cell growth. Just under half of all metastatic melanomas carry one of these mutant BRAF genes.

Tafinlar targets BRAF itself, much like Roche’s Zelboraf (vemurafenib), which was approved in 2011 with its own diagnostic test. However, Mekinist is the first approved drug to target MEK – another protein in the same signalling pathway.

The drugs are both produced by GlaxoSmithKline (GSK), and the diagnostic device has been developed in collaboration with French company Biomérieux.