New treatments for metastatic melanoma fall into two categories: immunotherapies that spur patients’ immune systems to attack the cancer and targeted therapies that block the molecules that allow the cancer to grow and spread.
Immunotherapies — Up to 60 percent of patients will respond to immune therapy. FDA-approved immunotherapies include pembrolizumab, nivolumab, talimogene laherparepvec, ipilimumab and nivolumab with ipilimumab. Survival rates have improved so dramatically in some patients that many researchers think immunotherapies may cure metastatic melanoma, but the treatments have not been around long enough for their long-term effect to be quantified. Researchers are still trying to understand why other patients don’t respond to immunotherapies.
Targeted therapies — Targeted therapies interfere with specific molecules involved in the growth and spread of cancers. Patients whose tumors express BRAF mutations, which comprise about half of people with metastatic melanoma, will respond to targeted therapies. Targeted therapies are also available for the MEK mutation and the C-KIT mutation. FDA-approved targeted therapies include vemurafenib, dabrafenib, trametinib, dabrafenib with trametinib, cobimetinib with vemurafenib and imatinib. Two combinations of targeted therapies, dabrafenib with trametinib (for high risk stage III melanoma) and encorafenib with binimetinib (for metastatic melanoma), received approvals in 2018. While almost all patients respond to targeted therapies, over time they develop resistance. Researchers are focused on making the targeted therapies work longer, preventing resistance or overcoming it when it happens.