Wikipedia
Nivolumab (nye vol' ue mab), marketed as Opdivo, is a humanized IgG4 anti- PD-1 monoclonal antibody used to treat cancer. Nivolumab works as a checkpoint inhibitor, blocking a signal that would have prevented activated T cells from attacking the cancer, thus allowing the immune system to clear the cancer. It was discovered at Medarex, developed by Medarex and Ono Pharmaceutical, and brought to market by Bristol-Myers Squibb (which acquired Medarex in 2009) and Ono.
As of April 2016, nivolumab was used as a first line treatment for inoperable or metastatic melanoma in combination with ipilimumab if the cancer does not have a mutation in BRAF (gene), as a second-line treatment following treatment with ipilimumab and if the cancer has a mutation in BRAF, with a BRAF inhibitor, as a second-line treatment for squamous non-small cell lung cancer, and as a second-line treatment for renal cell carcinoma.
It had not been tested in pregnant women but based on the mechanism of action and animal studies, is probably toxic to the fetus; it is not known if it is secreted in breast milk. Side effects include severe immune-related inflammation of the lungs, colon, liver, kidneys, and thyroid, and there are effects on skin, central nervous system, the heart, and the digestive system.