Association between immune-related adverse events and efficacy of PD-1 inhibitors in Chinese patients with advanced melanoma

Programmed cell death 1 (PD-1) checkpoint inhibitor therapy leads to immune-related adverse events (irAEs). We sought to evaluate whether the development of irAEs correlates with the treatment response in Chinese patients with advanced melanoma. In this study, we conducted a retrospective study of advanced melanoma patients who received PD-1 inhibitor therapy in China between August 2014 and March 2018. A total of 93 patients treated with PD-1 inhibitors including pembrolizumab and nivolumab were enrolled. The most frequent irAEs were pruritus, rash, vitiligo, and fatigue. The median time to onset of irAEs was 6.1 weeks. The overall response rate (ORR) and disease control rate (DCR) were higher in patients with irAEs than those without irAEs (P = 0.004 and P = 0.003, respectively), and better in patients who experienced three or more irAEs than those with none (P <0.001 and P <0.001, respectively). The ORR and DCR were significantly better in patients with grade 1 to 2 irAEs when compared with those with none (P = 0.002 and P = 0.003, respectively). In addition, the median progression-free survival and overall survival were longer in patients with irAEs than in those without irAEs (P = 0.007 and P = 0.002, respectively). In conclusion, our data demonstrated that irAEs were associated with a better clinical outcome after treatment with PD-1 inhibitor therapy in Chinese patients with advanced melanoma.