460 Background: We report a post hoc, exploratory analysis of pts with BL ML number and LL data who received nal-IRI+5-FU/LV, nal-IRI or 5-FU/LV in NAPOLI-1, a pivotal, phase 3 trial (NCT01494506). nal-IRI+5-FU/LV increased median OS (mOS) vs 5-FU/LV (6.1 vs 4.2 mo [HR=0.67; p=0.012]). Methods: ML (1, 2, 3, >3) and LL were recorded (local investigator) at BL. Pts with >1 LL were counted for each location. Results: 354 of 417 ITT pts had measurable BL ML and 1,080 LL were recorded. There was no clear trend in the percentage of pts with KPS ≥80 in 1- >3 ML (range 87%-95%) or LL (range 89%-94%) subgroups. ML 1 (n=81), 2 (n=65) and 3 (n=24) subgroups were small. nal-IRI+5-FU/LV significantly improved mOS vs. 5-FU/LV in pts with 2/>3 ML (n=184/24); nal-IRI+5-FU/LV had numerically higher mOS vs. 5-FU/LV for all LL (Table). nal-IRI+5-FU/LV had favourable median PFS (mPFS) vs. 5-FU/LV in pts with 1–>3 ML (range 2.0-4.2 vs. 1.4-1.9 mo; HR range 0.35-0.88) and for all LL (range 2.8-4.2 vs. 1.4-2.0 mo; HR range 0.39-0.55). Conclusions: Low pt numbers across groups and repeat counting of pts in LL subgroups preclude firm conclusions on treatment efficacy, pending further analyses. Allowing for these limitations, we detected no clear prognostic effect on outcomes of higher BL ML number or LL in NAPOLI-1 ITT pts. nal-IRI+5-FU/LV improved mOS vs. 5-FU/LV in some ML groups and across LL groups; improvement in mPFS vs. 5-FU/LV in the ITT population was maintained in all subgroups. Clinical trial information: NCT01494506. [Table: see text]