L. Orgiano

BRAF-mutant melanoma: treatment approaches, resistance mechanisms, and diagnostic strategies

BRAF inhibitors vemurafenib and dabrafenib achieved improved overall survival over chemotherapy and have been approved for the treatment of BRAF-mutated metastatic melanoma. More recently, the combination of BRAF inhibitor dabrafenib with MEK inhibitor trametinib has shown improved progression-free survival, compared to dabrafenib monotherapy, in a Phase II study and has received approval by the US Food and Drug Administration. However, even when treated with the combination, most patients develop mechanisms of acquired resistance, and some of them do not achieve tumor regression at all, because of intrinsic resistance to therapy. Along with the development of BRAF inhibitors, immunotherapy made an important step forward: ipilimumab, an anti-CTLA-4 monoclonal antibody, was approved for the treatment of metastatic melanoma; anti-PD-1 agents achieved promising results in Phase I/II trials, and data from Phase III studies will be ready soon. The availability of such drugs, which are effective regardless of BRAF status, has made the therapeutic approach more complex, as first-line treatment with BRAF inhibitors may not be the best choice for all BRAF-mutated patients. The aim of this paper is to review the systemic therapeutic options available today for patients affected by BRAF V600-mutated metastatic melanoma, as well as to summarize the mechanisms of resistance to BRAF inhibitors and discuss the possible strategies to overcome them. Moreover, since the molecular analysis of tumor specimens is now a pivotal and decisional factor in the treatment strategy of metastatic melanoma patients, the advances in the molecular detection techniques for the BRAF V600 mutation will be reported.

Potential Role of Soluble c-Met as a New Candidate Biomarker of Metastatic Uveal Melanoma

IMPORTANCE Conventional melanoma serum biomarkers (S100 and lactate dehydrogenase [LDH]) perform poorly in patients with uveal melanoma, and the search for new biomarkers is needed. A high expression of the oncoprotein c-Met in primary uveal melanoma is associated with metastatic progression, and c-Met is released as a soluble ectodomain through ADAM10- and ADAM17-mediated cleavage, suggesting a possible role as biomarker. OBJECTIVE To determine the potential role of soluble c-Met (sc-Met) as a biomarker of uveal melanoma progression in comparison with S100 and LDH. DESIGN, SETTING, AND PARTICIPANTS Soluble c-Met was studied in the conditioned medium of 9 uveal melanoma cell lines and in the blood serum samples of 24 mice with uveal melanoma xenografts, 57 patients with uveal melanoma (17 patients whose tumors metastasized and 40 patients whose tumors did not metastasize), and 37 healthy donors. We collected blood samples for as long as 5 years after treatment of the primary tumor. The concentration of sc-Met was measured using enzyme-linked immunosorbent assays, and the receiver operating characteristic curve was used to evaluate sensitivity and specificity in the identification of metastatic uveal melanoma. The study began on May 2, 2011, and the last samples were collected in January 2015. MAIN OUTCOMES AND MEASURES Levels of sc-Met in uveal melanoma cell cultures and in the blood serum samples of xenotransplanted mice, of healthy donors, and of patients with uveal melanoma during follow-up. RESULTS The conditioned medium of uveal melanoma cell lines and the blood serum samples of mice with uveal melanoma xenografts contained significant levels of sc-Met. Patients with metastatic disease had significantly higher serum levels of sc-Met (median level, 590 ng/mL [range, 246-12,856 ng/mL]) than did patients without metastatic disease (median level, 296 ng/mL [range, 201-469 ng/mL]) (P < .001) and healthy donors (median level, 285 ng/mL [range, 65-463 ng/mL]) (P < .001). Analysis of receiver operating characteristic curves for sc-Met levels in patients with nonmetastatic uveal melanoma vs patients with metastatic uveal melanoma yielded an area under the curve of 0.82 (95% CI, 0.68-0.95) (P < .001), which was superior to the areas under the curve achieved with S100 or LDH markers. Patients with progressive metastatic disease showed further increases in sc-Met level, whereas stable patients did not. CONCLUSIONS AND RELEVANCE The present pilot study suggests that sc-Met should be further exploited as a biomarker for monitoring of uveal melanoma.

Current status and perspectives in immunotherapy for metastatic melanoma

Metastatic melanoma was the first malignancy in which immune checkpoint inhibitors demonstrated their successful efficacy. Currently, the knowledge on the interaction between the immune system and malignant disease is steadily increasing and new drugs and therapeutic strategies are overlooking in the clinical scenario. To provide a comprehensive overview of immune modulating drugs currently available in the treatment of melanoma as well as to discuss of possible future strategies in the metastatic melanoma setting, the present review aims at analyzing controversial aspects about the optimal immunomodulating treatment sequences, the search for biomarkers of efficacy of immunocheckpoint inhibitors, and innovative combinations of drugs currently under investigation.

CARAMEL study: Clinical prognostic biomarkers for ipilimumab-related outcome in metastatic melanoma patients.

e21009Background: Ipilimumab is an inhibitor of CTLA4 receptor of T lymphocytes that has been approved by FDA both as first and second line treatment for patients with metastatic melanoma. Despite ...