The authors examine the use of pembroluzimab, a monoclonal antibody designed to block the PD-1 pathway in metastatic melanoma. PD-1 ligand has been found to be expressed on several cancer cells, including metastatic melanoma, and when bound to the PD-1 cell-surface receptor on T-cells, functions to reduce immune mediated destruction of those cancerous cells. Thus, blockade of this pathway has the potential to promote T-cell mediated cytotoxicity and reduce tumor burden. The authors note that further studies need to be done to establish which patients should receive treatment with pembroluzimab, and whether this treatment should be started after initial therapy with other monoclonal antibodies directed against differing cell surface receptors (i.e. BRAF/MEK). The use of monoclonal antibodies shows great promise as a future treatment option for a wide variety of diseases, and thus medical students, and all medical professionals, should be made aware of the amount of potential of such therapy.

Bhatia S, Thompson JA. PD-1 Blockade in Melanoma: A Promising Start, but a Long Way to Go. JAMA. 2016 Apr 19;315(15):1573-5.