Nivolumab is a monoclonal antibody used to treat several types of cancer, including melanoma, lung cancer, and kidney cancer. It is sold under the brand name Opdivo.

Bristol-Myers Squibb (BMS) is the manufacturer of Nivolumab. According to the company's website, BMS is "a global biopharmaceutical company whose mission is to discover, develop and deliver innovative medicines that help patients prevail over serious diseases."

According to the drugpatentwatch.com, Nivolumab is not currently under patent protection in several countries, including the United States, European Union, and Japan. However, BMS still holds the exclusive rights to manufacture and sell Nivolumab under the Opdivo brand.

In summary, Bristol-Myers Squibb (BMS) is the manufacturer of Nivolumab, which is sold under the brand name Opdivo. Nivolumab is not currently under patent protection in several countries, but BMS still holds the exclusive rights to manufacture and sell Nivolumab under the Opdivo brand.

Sources:

1. <https://www.drugpatentwatch.com/p/biologics/ingredient/nivolumab>
2. <https://www.opdivo.com/>
3. <https://www.bms.com/>