Nivolumab is a type of protein designed to attach to a certain type of white blood cells called the T cells. T cells are part of the immune system needed to attack the cancer. Nivolumab acts to improve the activity of T cells, thereby increasing the ability of the immune system to kill cancer cells. Ipilimumab is another type of protein that acts in a different way to increase the activity of T cells. If licenced, nivolumab in combination with ipilimumab will offer additional treatment option to prolong lives of this patient group.