e14661 Background: FOLFIRINOX is an important addition to our therapeutic armamentarium for the treatment of aPDAC; however, safety and tolerability issues (hematologic toxicity, increased risk of AE in pts carrying biliary stents) may limit its use in routine clinical practice. Methods: We reviewed the clinical charts of 36 aPDAC pts receiving first-line FOLFIRINOX at two different institutions and analyzed toxicity and outcomes according to the presence or absence of a biliary stent and whether they received (n=21) or not (n=15) primary prophylactic G-CSF (d 7-9-11). Results: 36 pts (M/F: 22/14; median age: 57 yrs, range: 37-70; stage III/IV: 10/26; ECOG PS 0/1: 33/3) and 241 cycles were analyzed. Toxicity was mild with G3/4 adverse events (AE) in <1% of cycles, except for G3/4 neutropenia (16.6% of pts, 3.7% of cycles); dose was reduced to 75% in 48/205 cycles (23%); 3 pts discontinued treatment after 1 cycle (G3 gastro-intestinal toxicity in 1 pt and early progressive disease, PD in 2 pts). Overall and G3/4 toxicities were not significantly different in 7 pts carrying a biliary stent. G3/4 neutropenia was observed in 5/155 (3.2%) and 4/86 (4.6%) cycles among pts receiving or not G-CSF prophylaxis (p=n.s.); anemia and thrombocytopenia (any grade) were more common among pts receiving G-CSF (p<0.001 and p=0.009, respectively). Palonosetron/aprepitant/dexamethasone achieved complete control of nausea/vomiting at cycle 1 in 72% (95% CI: 58-87%) and 86% (95% CI: 75-97%) of pts. Partial response (PR) occurred in 25% and stable disease (SD) in 43% of 28 evaluable pts (disease control rate, DCR: 68%, 95% CI: 51-85%). A >50% reduction in CA19.9 occurred in 61% of pts. Median PFS was 8 mos (95% CI: 6-9 mos). Conclusions: FOLFIRINOX is well tolerated and easily manageable on an outpatient basis in young (<70 yrs) and fit (PS 0-1) aPDAC pts and can be safely used in pts carrying biliary stents. Routine G-CSF prophylaxis is not currently recommended, but may be useful to carefully extend FOLFIRINOX use to older/less fit/comorbid pts with aPDAC.