The prognostic value of the derived neutrophil-to-lymphocyte ratio (dNLR) in patients treated with immune checkpoint inhibitors

Background The (derived) neutrophil-to-lymphocyte ratio (dNLR) is a potential predictive biomarker in the era of checkpoint inhibitors (CPI). An elevated dNLR is associated with worse outcomes across several malignancies. However, there is no clearly defined cut-off in the clinical setting. Aim To compare outcomes in patients prescribed CPI with a baseline dNLR(0) > 3 and dNLR(0) <= 3. The dNLR(6) was measured 6 weeks later to determine its impact on patient overall survival (OS). Methods Prospectively maintained pharmacy databases in a regional cancer centre were interrogated for patients who were prescribed CPI in the advanced setting between January 2017 and May 2020. Results There were 121 patients with advanced cancer and a median age of 68 (range 30 to 88) years. Forty-four percent (n = 53) received prior systemic therapy. Patients with an initial dNLR(0) > 3 when compared with a dNLR(0) <= 3 had significantly shorter median progression-free survival (PFS), 3 vs. 14 months (p = 0.001) and median OS, 6.4 vs. 30.2 months (p = 0.001). Patients with an initial dNLR(0) > 3 and increased dNLR at 6 weeks (dNLR(6)) had significantly reduced median PFS (3.5 vs. 14.7 months, p = 0.03) and OS (5.7 vs. 16.3, p = 0.03) when compared with those whose dNLR decreased. In the dNLR(0) <= 3 cohort, any increased dNLR when compared with decreased dNLR after 6 weeks of CPI had significantly reduced PFS (8.4 months vs. NR, p = 0.01) and OS (24.2 months vs. NR, p = 0.02). Conclusions Lower pre-CPI treatment dNLR is associated with improved OS. A decrease in dNLR during treatment confers improved OS.