Understanding the profile of oncogene and tumor suppressor gene mutations with their interactions and impact on the prognosis of multiple myeloma (MM) can improve the definition of disease subsets and identify pathways important in disease pathobiology. Using integrated genomics of 1273 newly diagnosed patients with MM, we identified 63 driver genes, some of which are novel, including ,, ,, and Oncogene mutations are significantly more clonal than tumor suppressor mutations, indicating they may exert a bigger selective pressure. Patients with more driver gene abnormalities are associated with worse outcomes, as are identified mechanisms of genomic instability. Oncogenic dependencies were identified between mutations in driver genes, common regions of copy number change, and primary translocation and hyperdiploidy events. These dependencies included associations with t(4;14) and mutations in, , and; t(11;14) with mutations in and; t(14;16) with mutations in ,, , and; and hyperdiploidy with gain 11q, mutations in , and rearrangements. These associations indicate that the genomic landscape of myeloma is predetermined by the primary events upon which further dependencies are built, giving rise to a nonrandom accumulation of genetic hits. Understanding these dependencies may elucidate potential evolutionary patterns and lead to better treatment regimens.

In multiple myeloma, there has been little progress in the specifi c therapeutic targeting of oncogenic mutations. Whole-genome sequencing data have recently revealed that a subset of patients carry an activating mutation (V600E) in the BRAF kinase. To uncover the clinical relevance of this mutation in multiple myeloma, we correlated the mutation status in primary tumor samples from 379 patients with myeloma with disease outcome. We found a signifi cantly higher incidence of extramedullary disease and a shorter overall survival in mutation carriers when compared with controls. Most importantly, we report on a patient with confi rmed BRAF V600E mutation and relapsed myeloma with extensive extramedullary disease, refractory to all approved therapeutic options, who has rapidly and durably responded to low doses of the mutation-specifi c BRAF inhibitor vermurafenib. Collectively, we provide evidence for the development of the BRAF V600E mutation in the context of clonal evolution and describe the prognostic and therapeutic relevance of this targetable mutation.SIGNIFICANCE: This is the fi rst evidence of the clinical and therapeutic relevance of BRAF V600E mutations in multiple myeloma, proving the principle of specifi c inhibition of driver mutations in this disease. Cancer Discov; 3(8);