Prognostic Biomarkers for Anti-PD-1 Monoclonal Antibodies in the First Line Treatment of Advanced Melanoma

Approximately 50% of patients with advanced melanoma treated with first-line anti-PD-1 immunotherapy achieve clinical benefit. However, to date, there are no validated biomarkers for objective response (ORR), progression-free survival (PFS), or overall survival (OS) with this treatment.

We performed a unicentric retrospective analysis of ORR, PFS, and OS in 138 patients with advanced melanoma treated with first-line anti-PD-1 monoclonal antibodies. Baseline blood parameters were analyzed as potential predictive or prognostic biomarkers. ORR was assessed using both RECIST (Response Evaluation Criteria In Solid Tumors) v.1.1 and iRECIST (Immune Response Evaluation Criteria In Solid Tumors). Survival analysis was performed using Kaplan-Meier curves, and comparisons were made using the log-rank test. Multivariate Cox regression analysis was used to determine independent prognostic factors for survival, and a logistic regression model was used for response.

The median follow-up was 44.1 (95% confidence interval [CI]: 40.4-49.4) months. Elevated pretreatment lactate dehydrogenase (LDH) level and systemic immune-inflammation index (SII) were negative prognostic factors for PFS. However, only LDH remained statistically significant on multivariate analysis [hazard ratio (HR) 1.72, 95% CI: 1.09-2.70, p = 0.019, HR 1.69, 95% CI: 0.95-3.00, p = 0.072]. Increased pretreatment LDH level and SII were both negative prognostic factors for OS on multivariate analysis (HR 2.25, 95% CI: 1.35-3.75, p = 0.002, HR 2.37, 95% CI: 1.29-4.37, p = 0.006).

Elevated pretreatment levels of SII and LDH were shown to be independent negative prognostic factors for OS. According to the nomogram for OS, which considers a combination of pretreatment parameters including LDH and SII, it is possible to predict 24-month OS in the first line of anti-PD-1 therapy.