Current and emerging treatment options for metastatic melanoma: a focused review.

Melanoma is responsible for nearly 9,000 deaths each year in the United States. Until the early 2000s, chemotherapeutic agents were the mainstay of treatment for metastatic disease. Currently approved treatments include therapies that block signal transduction pathways (BRAF inhibition), increase anti-tumor immune responses (CTLA-4 blockade), or stimulate tumor-infiltrating T cells (IL2). In recent years, various new strategies have emerged. Radiation therapy has been widely underutilized, but it can prime tumor cells that are distant from the field of radiation, a phenomenon termed the abscopal effect. Other therapies such as pembrolizumab disrupt the tumor cells' typical mechanisms of T-cell avoidance. Various other treatments involving imiquimod, adoptive T-cell therapy, and vaccines are currently being studied and can play a role in metastatic melanoma treatment in the future. Herein, we review the past treatment modalities, currently approved treatments, and potentially effective options for the future. We also provide strengths of recommendation and level of evidence for each treatment.