Prognostic value of baseline neutrophil-to-lymphocyte ratio for predicting clinical outcome in metastatic pancreatic ductal adenocarcinoma (mPDAC) patients treated with liposomal irinotecan (nal-IRI)+5-fluorouracil and leucovorin (5-FU/LV) vs 5-FU/LV alon

[[abstract]]Background: Elevated baseline neutrophil-to-lymphocyte ratio (NLR), a marker of subclinical inflammation, is associated with poor survival in several malignancies including mPDAC. Here we report the association of NLR with overall survival (OS) and progression-free survival (PFS) in a post-hoc analysis of the NAPOLI-1 trial (NCT01494506), that demonstrated improved survival with nal-IRI+5-FU/LV vs 5-FU/LV for treatment of mPDAC patients (pts) after disease progression following gemcitabine-based therapy. Methods: Pts treated with nal-IRI+5-FU/LV or 5-FU/LV and available baseline NLR data were included (data cutoff: Nov 16, 2015). OS and PFS were assessed in pts with high (>5) or low (≤5) baseline NLR in individual and pooled treatment arms. Results: Baseline NLR was available for 221 pts: 116/117 nal-IRI+ 5-FU/LV pts and 105/105 5-FU/LV pts. In the pooled treatment arms, pts with NLR≤5 had significantly better OS compared to pts with NLR >5 (6.2 vs 3.7 months, HR = 0.7, p = 0.02). Interestingly, this improvement in OS in pts with low vs high NLR was significant in the nal-IRI+5-FU/LV arm (8.4 vs 4.3 months, HR = 0.5, p=0.001); but not in the 5-FU/LV arm (4.8 vs 3.1 months, HR = 0.9, p=0.6). Similarly, PFS was significantly higher in pts with NLR≤5 vs NLR >5 in the pooled treatment arms (2.7 vs 1.4 months, HR = 0.7, p=0.05), and the nal-IRI+5-FU/LV arm (4.2 vs 1.4 months, HR = 0.5, p=0.002), but not the 5-FU/LV arm (1.5 vs 1.4 months, HR = 1.1, p=0.6). Conclusions: Data from these exploratory analyses are consistent with previous reports on the prognostic value of baseline NLR in mPDAC, and extend it to the post-gemcitabine setting. Median OS and PFS were improved in pts with low vs high baseline NLR in the nal-IRI+5-FU/LV arm but not in the 5-FU/LV arm. Clinical implications of these data remain to be determined