Melanoma: new insights and new therapies

Metastatic melanoma has historically been considered as one of the most therapeutically challenging malignancies. However, for the first time after decades of basic research and clinical investigation, new drugs have produced major clinical responses. The discovery of BRAF mutations in melanoma created the first opportunity to develop oncogene-directed therapy in this disease and led to the development of compounds that inhibit aberrant BRAF activity. A decade later, vemurafenib, an orally available and well-tolerated selective BRAF inhibitor, ushered in a new era of molecular treatments for advanced disease. Additional targets have been identified, and novel agents that impact on various signaling pathways or modulate the immune system hold the promise of a whole new therapeutic landscape for patients with metastatic melanoma. One of the major thrusts in melanoma therapy is now focused on understanding and targeting the network of signal transduction pathways and on attacking elements that underlie the tumor's propensity for growth and chemoresistance. In this article, we review the novel targeted anticancer approaches that are under consideration in melanoma treatment.

Bevacizumab and everolimus in the treatment of patients with metastatic melanoma: a phase 2 trial of the Sarah Cannon Oncology Research Consortium

BACKGROUND

In this phase 2 study, the activity and tolerability of the combination of bevacizumab, an inhibitor of angiogenesis, and everolimus, an inhibitor of the mammalian target of rapamycin (mTOR), was evaluated in the treatment of patients with metastatic melanoma.

METHODS

Patients with metastatic melanoma who had received up to 2 previous systemic regimens (chemotherapy and/or immunotherapy) were eligible. Previous treatment with angiogenesis or mTOR inhibitors was not allowed. All patients received bevacizumab at a dose of 15 mg/kg intravenously every 21 days and everolimus at a dose of 10 mg orally daily. Patients were re-evaluated every 6 weeks; those with an objective response or stable disease (according to Response Evaluation Criteria in Solid Tumors [RECIST]) continued therapy until tumor progression or unacceptable toxicity occurred.

RESULTS

Fifty-seven patients with metastatic melanoma received a median of 4 treatment cycles (range, 1-14+ cycles). Seven patients (12%) achieved major responses, whereas 33 patients (58%) were found to have stable disease at the time of first evaluation. The median progression-free and overall survivals were 4 months and 8.6 months, respectively. Approximately 43% of patients were alive after 12 months of follow-up. The treatment regimen was well tolerated by the majority of patients.

CONCLUSIONS

The combination of bevacizumab and everolimus was found to have moderate activity and was well tolerated in the treatment of patients with metastatic melanoma. Further exploration of agents with these mechanisms of action is indicated, perhaps in combination with inhibitors of the mitogen-activated protein kinase (MAPK) pathway.