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Targeted therapies with MAPK inhibitors (MAPKi) are faced with severe problems of resistance in BRAF‐mutant melanoma. In parallel to the acquisition of genetic mutations, melanoma cells may also adapt to the drugs through phenotype switching. The ZEB1 transcription factor, a known inducer of EMT and invasiveness, is now considered as a genuine oncogenic factor required for tumor initiation, cancer cell plasticity, and drug resistance in carcinomas. Here, we show that high levels of ZEB1 expression are associated with inherent resistance to MAPKi in BRAFV 600‐mutated cell lines and tumors. ZEB1 levels are also elevated in melanoma cells with acquired resistance and in biopsies from patients relapsing while under treatment. ZEB1 overexpression is sufficient to drive the emergence of resistance to MAPKi by promoting a reversible transition toward a MITF low/p75high stem‐like and tumorigenic phenotype. ZEB1 inhibition promotes cell differentiation, prevents tumorigenic growth in vivo, sensitizes naive melanoma cells to MAPKi, and induces cell death in resistant cells. Overall, our results demonstrate that ZEB1 is a major driver of melanoma cell plasticity, driving drug adaptation and phenotypic resistance to MAPKi.

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The disease course of BRAF (v-raf murine sarcoma viral oncogene homolog B1)-mutant melanoma has been drastically improved by the arrival of targeted therapies. NRAS (neuroblastoma RAS viral oncogene homolog)-mutated melanoma represents 15–25% of all metastatic melanoma patients. It currently does not have an approved targeted therapy. Metastatic patients receive immune-based therapies as first-line treatments, then cytotoxic chemotherapy like carboplatin/paclitaxel (C/P), dacarbazine (DTIC) or temozolomide (TMZ) as a second-line treatment. We will review current preclinical and clinical developments in NRAS-mutated melanoma, and analyze ongoing clinical trials that are evaluating the benefit of different targeted and immune-based therapies, either tested as single agents or in combination, in NRAS-mutant melanoma.

IMPORTANCE Melanoma treatment has been revolutionized with the development of immune-based therapies that offer durable clinical responses in a subset of patients. Clinical outcomes after treatment by immunotherapy can be influenced by the host's immune system. The immune system is modified with age by age-related immune dysfunction.OBJECTIVE To evaluate if age influences clinical outcome and immune adverse events in patients treated by immunotherapy for metastatic melanoma. DESIGN, SETTING, AND PARTICIPANTSThis was a single-center cohort analysis in patients treated with immunotherapy for metastatic melanoma between January 2007 and February 2016, in the Lyon Sud Hospital, France. A total of 92 patients with metastatic melanoma treated with ipilimumab, nivolumab, or pembrolizumab were retrospectively analyzed. MAIN OUTCOMES AND MEASURESOverall survival, progression-free survival, and immune-related adverse events were evaluated for each treatment line according to the patients' age.RESULTS A total of 92 patients were eligible and included in this study for a total of 120 lines of treatment. Fifty-four patients were included in the cohort that was 65 years or younger (24 [44%] were female; mean [SD] age, 48.1 [12.5] years), and 38 patients were included in the cohort that was older than 65 years (12 [34%] were female; mean [SD] age, 74.8 [6.9] years). Mean follow-up duration starting at treatment initiation was 12.5 months. Patients older than 65 years treated with immunotherapy had a better mean progression-free survival (4.8 vs 3.4 months; P = .04) and overall survival (not reached vs 10.1 months; P = .009) than younger patients in univariate analysis, and after adjusting on prognosis covariates. This was particularly true with patients treated with anti-programmed cell death protein 1. Common immune-related adverse effects were similar in both cohorts.CONCLUSIONS AND RELEVANCE Age might be associated with a better clinical outcome after treatment with immunotherapy in the real-life setting. In our cohort, older patients did not have more immune-related adverse events. Further studies are warranted to confirm our results and describe the underlying mechanisms involved.

Our study shows that, in the context of continuing medical education, a spaced education Internet dermoscopy module combined with in-class training increases participant performances in dermoscopy. It is easy to use and adaptable to professional working schedules.

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The combination of cobimetinib and vemurafenib seems to be more toxic than the combination therapy dabrafenib and trametinib even if these four drugs have never been compared in a randomized trial. The future of this combination depends on its capacity to be combined simultaneously or sequentially with immune based therapies to improve the durability of responses.