Prognostic value of the <scp>CONUT</scp> score with immune checkpoint inhibitors as first‐line therapy for metastatic malignant melanoma

The recent availability of immune checkpoint inhibitors (ICIs) has revolutionized the treatment of advanced malignant melanoma (MM). However, many patients with MM do not benefit from ICI treatment. As immunotherapy is associated with significant toxicity and high treatment costs despite its excellent efficacy, it is pertinent to select patients who are likely to respond to ICIs. In this single-center, retrospective study we investigated whether the controlling nutritional status (CONUT) score is a useful prognostic marker in Japanese patients with advanced-stage cancer. We analyzed 123 patients with stage IV MM treated with ICIs as first-line systemic treatment at our hospital between February 2012 and July 2024. Receiver operating characteristic curve analysis was used to calculate the CONUT cut-off value and CONUT into two groups of ≥3 and ≤2. Progression-free survival (PFS) and overall survival (OS) were determined using the Kaplan-Meier method, and differences in survival were assessed using the log-rank test. The Cox proportional hazard regression model was used to evaluate independent prognostic factors. Objective response rate (ORR), PFS, and OS were significantly low in the CONUT ≥3 group, characterized by low nutritional status and high inflammation. Multivariate analysis identified the CONUT score as an independent prognostic factor for both PFS and OS. The CONUT score was not significantly associated with the development of serious immune-related adverse events. The simplicity of the CONUT score may aid in identifying patients with MM who are suitable candidates for ICI treatment.