This study focuses on patients with unresectable stage III–IV melanoma, which is a serious type of skin cancer that cannot be removed by surgery. The purpose of the study is to compare two different ways of giving medication to see how they affect the immune system’s response to the cancer. One approach involves using ipilimumab, an immunotherapy drug that helps the body’s own defenses fight cancer, alongside nivolumab. In one part of the study, ipilimumab is given through an intradermal injection, which means the medicine is injected just under the surface of the skin, while nivolumab is given through an intravenous infusion, which is a liquid delivered directly into a vein.

The other part of the study uses the standard method where both ipilimumab and nivolumab are given through intravenous infusion. Researchers will look at how these different methods change the tumour microenvironment, which refers to the area immediately surrounding the cancer cells. The study will also monitor the activity of T cells, which are specific white blood cells that play a key role in the body’s ability to attack harmful cells, as well as Tregs, a type of cell that can sometimes prevent the immune system from working too strongly against the cancer.