Anti-BRAF monoclonal antibody, clone 5C3

Introduction Approximately 40-50% of patients with cutaneous melanoma harbor point mutations inBRAF. BRAF and MEK inhibitors in combination are now a standard therapy for advancedBRAF(V600)-mutated melanoma. Nevertheless, survival rates with the combination are limited, highlighting the need for further therapeutic improvement and strategies to overcome primary and acquired resistance. Areas covered Encorafenib, a highly selective BRAF inhibitor, was developed in combination with binimetinib, a potent, selective allosteric MEK1/2 inhibitor, to improve efficacy and tolerability over other approved combo-targeted therapies. This novel combination shows peculiar pharmacodynamic properties which translate in a higher on-target potency and paradox index. Consistent survival improvements for encorafenib and binimetinib inBRAF(V600)-mutated melanoma have been confirmed in clinical trials, with over 4 years of median follow up. Expert opinion the favorable survival results and the attractive toxicity profile suggest that encorafenib and binimetinib combination is an intriguing standard option when targeted therapies are considered as first line treatment in BRAF mutated melanoma patients. In the near future, results from ongoing clinical trials will provide information on the use of this novel combination in specific situation, including as adjuvant treatment or as a combination strategy.

Melanomas arising in the mucous membranes are a rare and aggressive subtype. New treatment approaches are needed, yet accumulating sufficient evidence to improve patient outcomes is difficult. Clinical and pathological correlates between human and canine mucosal melanomas are substantial, and the relatively greater incidence of spontaneous naturally occurring mucosal melanoma in dogs represents a promising opportunity for predictive modeling. The genomic landscapes of human and canine mucosal melanoma appear highly diverse and generally lack recurring hotspot mutations associated with cutaneous melanomas. Although much remains to be determined, evidence indicates that Ras/MAPK and/or PI3K/AKT/mTOR signaling pathway activations are common in both species and may represent targets for therapeutic intervention. Sapanisertib, an mTORC1/2 inhibitor, was selected from a PI3K/mTOR inhibitor library to collaborate with MEK inhibition; the latter preclinical efficacy was demonstrated previously for canine mucosal melanoma. Combined inhibition of MEK and mTORC1/2, using trametinib and sapanisertib, produced apoptosis and cell-cycle alteration, synergistically reducing cell survival in canine mucosal melanoma cell lines with varying basal signaling activation levels. Compared with individual inhibitors, a staggered sapanisertib dose, coupled with daily trametinib, was optimal for limiting primary mucosal melanoma xenograft growth in mice, and tumor dissemination in a metastasis model, while minimizing hematologic and renal side effects. Inhibitors downmodulated respective signaling targets and the combination additionally suppressed pathway reciprocal crosstalk. The combination did not significantly change plasma sapanisertib pharmacokinetics; however, trametinib area under the curve was increased in the presence of sapanisertib. Targeting Ras/MAPK and PI3K/AKT/mTOR signal transduction pathways appear rational therapies for canine and human mucosal melanoma.