opdivo is a medicine that may treat certain cancers by working with your immune system. Opdivo can cause  the  immune system to attack normal organs and tissues in any area of the body and can affect the way they work. These problems can sometimes become serious or life-threatening . These problems may happen anytime during treatment or even after your treatment has ended. Some of these problems may happen more often when opdivo is used in combination with yervoy opdivo ®  (nivolumab) is a prescription medicine used to treat a type of skin cancer called melanoma that has spread or cannot be removed by surgery (advanced melanoma). You may receive opdivo alone or in combination with  yervoy ®  (ipilimumab).  opdivo in combination with yervoy was approved based on the amount of time patients lived without their tumors worsening. There is ongoing evaluation of clinical benefit of opdivo in combination with yervoy for this use. opdivo (10 mg/ml) and yervoy  (5 mg/ml)  are injections for intravenous (iv) use.