BRAF and hairy cell leukemia: BRAF inhibitors such as vemurafenib are currently not approved in HCL and are used “off-label” in patients with refractory/relapsed HCL [14] In two phase 2 studies in 2015, that enrolled 54 BRAF-mutated HCL patients relapsed/refractory to purine analogue-based treatments, vemurafenib was administered at the standard melanoma dose of 960 mg twice daily for 16–18 weeks, respectively [15].