Marcus Butler, MD, from the Princess Margaret Cancer Centre, Toronto, Canada, discusses targeted therapies in melanoma patients at the European Cancer Congress of the European Cancer Organisation (ECCO) 2017 in Amsterdam, Netherlands. Approximately 40% of patients with melanoma have a BRAF mutation. There are therapies being developed for melanoma that target specific gene mutations. A way of determining which patients are most likely to respond to a specific treatment is to start them on a treatment, and then biopsy or look for specific biomarkers. Patients can then be switched to a different treatment if it is deemed to be more effective.