Nivolumab was developed as a monoclonal antibody against programmed death 
receptor-1, an immune checkpoint inhibitor which negatively regulates T-cell 
proliferation and activation. Intravenous administration of nivolumab was 
approved for the treatment of unresectable malignant melanoma in 2014 in Japan. 
When advanced melanoma patients were treated with nivolumab, median overall 
survival became longer. Overall survival rate was significantly better in 
nivolumab-treated melanoma patients than dacarbazine-treated melanoma patients. 
Nivolumab had an acceptable long-term tolerability profile, with 22% of patients 
experiencing grade 3 or 4 adverse events related to the drug. Therefore, 
nivolumab can become an alternative therapy for advanced malignant melanoma.