The Pan-Immune-Inflammation Value in Patients with Metastatic Melanoma Receiving First-Line Therapy

Background: Since a non-negligible fraction of patients with metastatic melanoma does not experience long-term disease control, even with immunotherapy and targeted therapy, new biomarkers for patient stratification and treatment tailoring are needed in this setting. Objective: We investigated the association of a novel immune-inflammatory blood-based biomarker, the Pan-Immune-Inflammation Value (PIV), with clinical outcomes of patients with metastatic melanoma receiving first-line therapy. Patients and Methods: We retrospectively included patients treated at the Fondazione IRCCS Istituto Nazionale dei Tumori of Milan and having an available baseline complete blood cell count (CBC). PIV was calculated as: [neutrophil count (103/mm3) × platelet count (103/mm3) × monocyte count (103/mm3)]/lymphocyte count (103/mm3). Results: A total of 228 patients were included: 119 (52%) had been treated with immunotherapy and 109 (48%) with targeted therapy. PIV was significantly higher in patients with ECOG PS ≥ 1, high disease burden, synchronous metastases, and elevated baseline LDH level. High baseline PIV was independently associated with poor overall survival (adjusted hazard ratio [HR]: 2.06; 95% confidence interval [CI]: 1.30–3.29; adjusted P = 0.002) and progression-free survival (adjusted HR 1.56; 95% CI 1.01–2.41; adjusted P = 0.044). High PIV was also associated with primary resistance to both immunotherapy (odds ratio [OR]: 3.98; 95% CI 1.45–12.32; P = 0.005) and targeted therapy (OR: 8.42; 95% CI 2.50–34.5; P < 0.001). PIV showed a promising discrimination ability in terms of AIC and c-index when compared with other CBC-based biomarkers. Conclusions: PIV may guide the treatment decision process and the development of novel first-line treatment strategies in melanoma, but warrants further study and validation.