Opdivo Qvantig is part of the Monoclonal Antibodies class and treats Esophageal Cancer, Lung Cancer, Skin Cancer and other conditions. Monoclonal antibodies are used to treat many conditions, including cancers, autoimmune diseases, and certain infections. They are similar to the antibodies in the body's immune system. But they are lab-made to have a specific target based on the condition they treat. Targets can include cancer cells, viruses, immune cells, and certain receptors in the body. Opdivo Qvantig is only available as a brand name drug.