Neoadjuvant Pembrolizumab for Unresectable Stage III and Unresectable Stage IV Melanoma

This study is being done to see if using the study drug, pembrolizumab, can shrink down melanoma tumors enough so that they will be small enough to cut out, so that there will be no cancer left in the body. Eligible participants include those who have not received any systemic melanoma therapies (i.e. participants do not have to fail ipilimumab or BRAF inhibitor) and those who have failed all available systemic options (if the participant meets other inclusion / exclusion criteria). For most melanoma cases, surgery is the recommended treatment. Until recently surgery was not used for patients with advanced melanoma (melanoma that has spread to lymph nodes or melanoma that has spread to other organs like the lung, liver, brain) because it was thought that surgery wouldn't help patients live longer when the melanoma tumors had spread beyond the skin. Recent studies have shown that patients with advanced melanoma who have surgery as one of their treatments may live longer than patients who only have systemic therapy (IV drugs or pills) and do not have surgery at all. Unfortunately, when patients with advanced melanoma come to the doctor, surgery is not a good choice for most patients because they have 'unresectable' melanoma. 'Unresectable' melanoma means they have melanoma tumors in the body that are too big or too close to important parts in the body (like big blood vessels) to be cut out safely. We are studying if we can use a drug to shrink tumors down to make them small enough to cut out; this is called a "neoadjuvant" approach to treating melanoma. By removing all of the cancer from body by using the combination of drug and surgery, we think this could help people live longer. Pembrolizumab is a drug that is given in the veins and can make the immune system stronger so that it can fight cancer cells. Pembrolizumab is in the class of drugs called immunotherapy. Immunotherapy uses parts of a person's immune system to fight the disease. Pembrolizumab is designed to restore the natural ability of the immune system to recognize and target melanoma cells to be attacked. In addition to possibly shrinking tumors, it may change your immune system so that it can fight melanoma in the future. We are also trying to learn more about how pembrolizumab works in the body. In this study, we will look at the skin, blood, and bone marrow to see if we can see any signs to tell doctors whether pembrolizumab is working or tell us which patients it may work on.