Prognostic Significance of the Modified Glasgow Prognostic Score in Patients With Stage <scp>IV</scp> Melanoma Receiving Immune Checkpoint Inhibitors: A Single‐Center Retrospective Study

Immune checkpoint inhibitors (ICIs) have transformed the treatment landscape for malignant melanoma (MM). However, given variable response rates and potential toxicities, identifying robust biomarkers is crucial. We investigated whether the modified Glasgow Prognostic Score (mGPS) predicts treatment efficacy and toxicity in Asian patients with advanced MM receiving first-line ICIs. We retrospectively analyzed 132 patients with stage IV MM treated at Shizuoka Cancer Center between 2012 and 2024. Patients were stratified by mGPS, which integrates C-reactive protein and albumin levels. Outcomes included objective response rate (ORR), progression-free survival (PFS), overall survival (OS), and the incidence of severe adverse events. The cohort was distributed as mGPS0 (70.5%), mGPS1 (12.9%), and mGPS2 (16.7%). Treatment efficacy declined notably with higher scores: ORR was 28.0% for mGPS0 and 23.5% for mGPS1, but dropped to 4.5% for mGPS2. Survival analysis revealed a clear prognostic stratification; median PFS was 6.2, 2.5, and 1.5 months, and median OS was 23.5, 14.6, and 1.9 months for mGPS0, mGPS1, and mGPS2, respectively. The mGPS2 group demonstrated significantly worse survival outcomes compared to the mGPS0 group. Conversely, the incidence of grade ≥ 3 adverse events did not differ significantly among the categories. The mGPS is a simple, accessible biomarker reflecting systemic inflammation and nutritional status. It effectively predicts ICI treatment outcomes in patients with advanced MM, particularly identifying those with mGPS2 as having a significantly poor prognosis.