Molecular features for selecting Asian metastatic melanoma patients who benefit from check-point inhibitors.

Abstract

e22011 Background: There was few data for molecular characteristics of Asian metastatic melanoma patients with distinct clinical features as compared to West patients with metastatic melanoma. We conducted the molecular profiling for Asian metastatic melanoma patients with check-point inhibitors (CPIs) to find novel biomarkers to CPIs. Methods: 164 Asian patients with metastatic melanoma who received CPIs were simultaneously tested by the next generation sequencing (NGS) in tumor samples. We collected all NGS data and clinic-pathologic factors and also analyzed biomarkers for tumor response to CPIs. Results: The most common subtype was acral melanoma (39.6%) followed by cutaneous melanoma (32.3%), mucosal melanoma (26.2%) and others (1.8%). 163 pts are evaluable for efficacy; we observed 40 complete response (24.4 %), 34 confirmed partial responses (20.7%), 41 stable disease (25.0%) and 48 disease progression (29.3%). The overall confirmed response rate from the dose escalation is 45.1%. There was no significant difference of tumor response among subtypes of melanoma (p = 0.295). NRAS and TP53 mutation and NF2 deletion were significantly related to patients without the response to CPIs (p < 0.05). Meanwhile, MYC and RPS6KB1 amplification were found with those with the response (p < 0.05). The median progression free survival (PFS) to ICIS was 5.9 months (95% CI 3.8 - 8.05 months). Univariate analysis showed that TP53 and BRAF mutation, NF2 deletion, and BIRC2 amplification were poor prognostic values for PFS (p < 0.05). Conclusions: This study reported molecular characteristics of 164 Asian patients with metastatic melanoma. The specific molecular alterations influenced on the tumor response and PFS to CPIs in those.