PDCD1 and nasopharyngeal carcinoma: Compared to the trials that assessed the anti-tumor activity of different PD-1 antibody monotherapies in pretreated RM-NPC, the ORR from our study was slightly higher (39.1% vs. 20.5–34%), as was the median PFS (7.5 months vs. 1.9–6.5 months) [12–15].