The impact of immunosenescence on the efficacy of immune checkpoint inhibitors in melanoma patients: a meta-analysis

BACKGROUND: Immunosenescence, the age-related decline of immunity, affects the immune responses of melanoma patients. Through immune responses, immune checkpoint inhibitors (ICIs) exert their antitumor robustness. In different ages of melanoma patients, especially the older patients, the effectiveness of ICIs remains unclear. It is still controversial whether ICIs should be used in treating older patients. MATERIALS AND METHODS: The authors included clinical trials of ICIs in older and younger patients. The authors used hazard ratio (HR) and 95% CI of overall survival (OS). RESULTS: From four phase III randomized clinical trials 2,251 melanoma patients were included. We found that ICIs significantly prolonged the OS for melanoma patients in both younger (HR, 0.71; 95% CI, 0.60–0.82; P<0.001) and older groups (HR, 0.62; 95% CI, 0.41–0.83; P<0.001) compared with controls. Anti-programmed death-1 (PD-1) agents appeared to be more efficient in older melanoma patients (HR, 0.34; 95% CI, 0.14–0.53) versus younger patients (HR, 0.52; 95% CI, 0.26–0.78). CONCLUSION: ICIs significantly prolonged the OS for melanoma patients in both younger and older groups than controls. Anti-PD-1 agents were more efficient in older melanoma patients versus younger patients. ICIs could be used for older melanoma patients.