PDCD1 and melanoma: However, data from recent clinical trials revealed a modest overall response rate (ORR) to the PD-1 blockade of less than 20% (4, 14), and a lack of dramatic responses in most patients (15) when compared with the more impressive ORRs of up to 57% in other advanced/pretreated indications, such as non-small cell lung cancer and melanoma (16, 17).