Notably, genetic alterations in the p53 pathway (CDKNA2 loss, MDM2 gain/amplification and TP53 mutation) accounted for 36.4% and were significantly associated with unfavourable PFS (median PFS 2.7 months vs. 3.9 months, P = 0.0394). Moreover, 26 genes were identified as differentially expressed genes that were upregulated in patients with clinical benefits compared to those without benefits. Four genes, GZMH, GZMK, AIM2 and CTLA4, were found to be associated with both PFS and OS....Genetic alterations in the p53 pathway may be critical in Asian patients with melanoma undergoing ICI treatment....A total of 26 genes were identified as DEGs upregulated in the CB cohort compared to the non-CB cohort, and high expression of GZMH, GZMK, AIM2 and CTLA4 was associated with favourable PFS and OS.