The optimal treatment sequence for patients with advanced BRAF V600 mutant melanoma is unknown.,BRAF/MEK inhibition (BRAF/MEKi), single agent anti‐PD‐1 (aPD‐1) antibodies and combination immune checkpoint inhibition with nivolumab and ipilimumab (niv/ipi) are all approved; however, they have not been prospectively compared.,Therefore, we sought to compare overall survival of patients with advanced BRAF mutant melanoma treated with either front‐line BRAF/MEKi, aPD‐1, or niv/ipi.,Patients with advanced BRAF mutant melanoma who had received BRAF/MEKi, niv/ipi, or aPD‐1 in the front‐line setting were identified from a nationwide database comprising de‐identified patient‐level structured and unstructured data derived from electronic health records.,Survival was compared using Kaplan‐Meier curves and log‐rank analysis.,Univariate and multivariate Cox regression models were used to measure the effect of front‐line treatment, age (>64 or not), LDH (elevated or not), and Eastern Cooperative Oncology Group (ECOG) performance status (>1 or not) on survival.,Five hundred and sixty seven patients with advanced disease and treated with front‐line aPD‐1 (n = 162), BRAF/MEKi (n = 297) or niv/ipi (n = 108) were identified.,With a median follow‐up of 22.4 months, median overall survival (OS) for patients treated with front‐line niv/ipi was not reached (NR) while median OS for patients treated with aPD‐1 or BRAF/MEKi was 39.5 months and 13.2 months, respectively.,Front‐line treatment with PD‐1 and niv/ipi were associated with statistically longer survival than BRAF/MEKi in multivariate analyses.,In our real‐world retrospective analysis, patients with advanced BRAF mutant melanoma treated with front‐line niv/ipi or aPD‐1 had longer survival compared to those treated with front‐line BRAF/MEKi.,Real‐world overall survival of patients with advanced BRAF mutant melanoma treated with front‐line BRAF/MEK inhibitors, anti‐PD‐1 antibodies, or nivolumab/ipilimumab.
The development of acquired drug resistance hampers the long-term success of B-RAF inhibitor (B-RAFi) therapy for melanoma patients.,Here we show V600EB-RAF copy number gain as a mechanism of acquired B-RAFi resistance in four out of twenty (20%) patients treated with B-RAFi.,In cell lines, V600EB-RAF over-expression and knockdown conferred B-RAFi resistance and sensitivity, respectively.,In V600EB-RAF amplification-driven (vs. mutant N-RAS-driven) B-RAFi resistance, ERK reactivation is saturable, with higher doses of vemurafenib down-regulating pERK and re-sensitizing melanoma cells to B-RAFi.,These two mechanisms of ERK reactivation are sensitive to the MEK1/2 inhibitor AZD6244/selumetinib or its combination with the B-RAFi vemurafenib.,In contrast to mutant N-RAS-mediated V600EB-RAF bypass, which is sensitive to C-RAF knockdown, V600EB-RAF amplification-mediated resistance functions largely independently of C-RAF.,Thus, alternative clinical strategies may potentially overcome distinct modes of ERK reactivation underlying acquired B-RAFi resistance in melanoma.