Figure 2. eNAMPT levels are significantly increased in patients with MM and correlate with response to therapy and overall survival.

(A) eNAMPT levels measured using an ELISA assay in sera from healthy donors (HD, n = 38), patients with a localized melanoma (LM, n = 50) or patients with metastatic disease (MM, n = 113). (B) ELISA assay showing eNAMPT concentrations in sera of stage IV melanoma patients subdivided in M1a, M1b and M1c subcategories. The horizontal line in (A–B) around 2 ng/ml indicated mean eNAMPT level in HD subjects. (C) Regression line showing a positive correlation between LDH (x-axis) and eNAMPT (y-axis) levels detected in 39 sera from MM patients. Pearson coefficient (r) and the corresponding P value are noted. (D) ELISA assay showing eNAMPT concentrations in sera from MM patients with PD-L1⁺ (n = 8) or PD-L1^- (n = 18) lesion (cut-off level >5% or <5% respectively). (E) eNAMPT activity determined in sera from 5 MM patients, with variable eNAMPT levels (indicated in brackets as ng/ml for each MM serum), as described in the Methods section. (F) Kaplan–Meyer curves showing overall survival (OS) of a cohort of 62 MM patients divided on the basis of eNAMPT levels (cut-off 12.72 ng/ml) at diagnosis. Log-rank test showed statistical significance. (G) ELISA assay showing eNAMPT concentrations in sera from 50 MM patients before and after therapy with a BRAFi alone or in combination with MEKi (T = 0). Graph on the left shows eNAMPT values before therapy and after 1 month of treatment (T = 1), where all patients showed some degree of response. The central panels shows eNAMPT levels in sera from 28 responsive MM patients at T = 1 (1 month of therapy) and at T = R (2–6 months later with consolidation of the clinical response). The graph on the right shows values in 22 progressive MM patients at T = 1 (1 month of therapy) and at T = P (at time of progression 6 months. The horizontal line, in all graphs indicates the mean eNAMPT level in HD subjects.